BAC Forum
General Boards => Technical Support => Topic started by: Tim Bentley Co-Admin on November 18, 2012, 11:03:32 PM
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Need help with a transmission problem. My Allison 4000 is running hot. It usually runs at under 200 Degrees, but is now running at 220 to 235. If I keep my speed at 60 in 5 gear, I can keep it at temp below 227. My transmission fluid and filters were changed less than 1000 miles ago. Three Questions. What can cause a transmission to run hot? Can I continue my trip, about 500 more miles, without damaging the transmission? Is it possible that they could have put the wrong type of fluid in at the change, is there more than one type of TranSynd?
I have no warning lights or Fault codes.
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Tim,
A few questions. First, are you sure that the transmission is full of fluid (check fluid level with transmission shift pad)? Next, does the transmission read the same temperature on your Aladdin as it does on your dash gauge?
There is the possibility that you have a gauge failure, and the transmission really is not that hot. Therefore the need to check more than one gauge. There is only one TranSynd as far as I know.
If your transmission really is running that hot on the highway, I would have it checked if possible before driving another 500 miles.
Gerald
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I have checked the fluid level and it is OK, Both gauges read the same.
I really would like to drive home taking it easy. Will I get a check transmission warning light before any serious damage is done?
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Tim,
I do not know. The thing that is the most concerning to me is, what is causing the overheating?
Gerald
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Tim,
Some discussion here with some feedback regarding 250F being a limit requiring cooling down. The fluids degrade at a higher rate as the temperature goes up but having Transynd is much more forgiving.
http://www.irv2.com/forums/f22/allison-trans-temp-73891.html
It is a matter of flow, both fluid and air, and if there is any slippage in the transmission. If the heat exchanger for the transmission is clean, then I would guess the next thing to try is to pull the transmission filters and see what they look like for particles, proper installation, and fluids. That could be done by a road service in the campground. Just a thought along with calling Allison for advice.
Later Ed
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Did you check for transmission codes? Are the radiators clean?
Steve Jewell
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Haven't cleaned in radiator in awhile, will do that but not sure if a dirty radiator would cause a 30 degree rise over night. The fact that it started after the service should be a clue. I did check the fluid cold at the dip stick and it was low, have not checked it hot yet. The fluid level read ok up front at the shifter, is it possible that reading is incorrect?
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The shifter/keypad is supposed to be more accurate than the dipstick.
When you are in 5th at 60, does the Aladin show 5C (clutch) or 5L (locked)?
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Several thoughts. A sudden temperature increase of 30 degrees, while not major, is also not normal and should be investigated. If fluid level has been confirmed by the shifter method (less chance of a miss-calibrated dipstick giving false readings) then the next step would be to review the cooling system. Several logical suggestions have already been given regarding the inspection and cleaning of the radiator. I'm assuming there is no associated increase in engine temperature? Question, were genuine Allison filters used at the recent change? Some aftermarket filters have been known to collapse under normal operating conditions. Internal transmission failures that would result in sudden increase in temperature would usually also be associated with some performance problems. Converter stator failure can cause overheat but would also result in a significant reduction in acceleration, a greater than 30 temperature spike, and will usually produce aluminum "sheen" in the fluid. Slipping clutch packs can cause temperature increases but would again result in noticeable performance problems and specific diagnostic codes. Please note that Allison provides specific thresholds to define Overheat and where to measure those temperatures. Per their Operators Manual (available for free download from Allison's website http://www.allisontransmission.com/index.jsp [search for Operators Tips]), SUMP TEMP shall be considered Overheat above 250 F. TO COOLER shall be considered Overheat above 300 F. If the unit is equipped with a transmission retarder, then RETARDER OUT temp of above 330 F is considered Overheat. As has already noted, TRANSYND is a very forgiving synthetic fluid so you should not experience any reduction in life based on a short term (relatively minor) fluid temp increase. However for something like this, my two cents is to contact an authorized Allison service outlet for guidance. Allison's website has a service locator that can point you in the right direction for service support based on your location. Good luck.
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Tim,
Even if the fluid was a bit low I do not think that would be a reason for such a temperature rise. Lower volume of fluid might account for a small shift in traditional temp due to fluid volume differences, but with proper flow it still sees the cooler and the pan should still have volume in it as a reservoir to pull from and the temperatures should be stable within a few degrees.
Given these transmissions are very reliable by design I agree that it is likely that some error in the service is the most logical source to have induced this issue. This problem timing just does not seem likely due to chance. When you look at the service performed there are two components, fluid and filters. Even if they inadvertenty used Dexron it would still not account for a significant temeprature shift, That leaves filters or a possible fluid or particle contamination of your transmission. (like antifreeze fill from a bulk system selection error} Like Keith I'm still thinking that improper filter PN or install may be involved. Not sure what your status is right now but I would be looking to have the filters inspected and changed and a fluid sample analysed to see where the current fluid maintenance stands and if it can shed some light on your problem. These transmissions are just too expensive to not sort this issue out when in doubt.
Regards Ed
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Tim,
Just a thought. When we changed from Dextron to TranSyn in our '98 Patriot, the transmission and engine temperature dropped about 30 degrees. It is possible they put in Dextron. I think the color is different, but you know me and colors.
Larry
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Still working on a fix for this problem. Allison in St George, Utah says fluid level and type are OK. They suspect its the transmission cooler, did not want to interupt trip to fix at this time. Will drive 58 in 5th to keep temp below 230, max temp is 250 so should not harm unit.
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..... Will drive 58 in 5th........
My fuel mileage improves significantly when I do that.
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Not so good news on our transmission. Looks like a transmission cooler leak allowed coolant to enter the transmission. The transmission cooler and transmission need to be replaced. As we have found out before, any coolant in the transmission will ruin it.
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Tim--
Sorry to hear your diagnosis. That's one of the frightening issues I hope never to have to face. I did some surfing and it does appear that there are a fair number of remanufactured 4060 tranny's for sale. Good luck.
Joel
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Tim,
This seems so strange that it coincided with a transmission oil service timing wise. Did you also see a loss of coolant or contaminated antifreeze? If not maybe there is a chance they added the wrong fluid to the transmission at time of service.
later Ed
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Tim: Sorry to hear about the outcome. Not what anyone had hoped for. If you decide pursue a used transmission, I'd suggest requesting a dated dyno report from the seller indicating it's health (or pay to have the unit run on a transmission dyno yourself). As you know, the removal/replacement labor is going to be significant, so you don't want to have to go through it twice. Regards,
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Tim: Another thought. As you search for replacement options please keep in mind that there are subtle differences in the 4000 Series transmissions based on year of manufacture (and of course, the Assembly Number found on the transmission data tag). You will want to avoid any unintended issues such as harness connector changes or calibration compatibility problems that could add to the complexity of the job. I would suggest working with an experienced service outlet to help you with the selection process (my vote will always be to stick with an Authorized Allison distributor or dealer). Regards
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Has this diagnosis been determined by an authorized Allision tech center? The reason I ask is that the manual says to test the fluid and if found contaminated to change the seals gasket etc. It implies damages not a need for an entire new transmission. I would call Allision before doing anything. This just doesn't seem right. You wouldn't be the first RVer to be told something that just doesn't need to be done.
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Here's an Allison "service tip" dealing with glycol coolant in the transmission fluid. To echo John Hennessey's point, nowhere in this note is a transmission replacement indicated.
http://www.allisontransmission.com/servlet/DownloadOnDemand?ApplicationID=155&DownloadID=6
The key recommendation is:
Any trace of Glycol or greater than 0.2% water contamination requires a complete disassembly and cleanup of the
transmission and replacement of seals, gaskets, clutch plates, and bearings.
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The point here is that both John and Joel are saying that the transmission will need to be overhauled. That is the term that is commonly used for replacing the clutches, seals and bearings. It is normally cheaper to replace the transmission with a rebuilt transmission than it is to rebuild your transmission because of the labor difference between a factory worker sitting at a bench assembling transmission parts at $20 an hour and the labor rates that you have for and experienced transmission technician at a repair shop. Therefore you just replace the transmission with a rebuilt transmission if it is contaminated with coolant.
Gerald
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We are working with Vally Power Systems the Allison dealer in San Diego. We will get a factory rebuilt transmission and new cooler.
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Need help with another problem. Apparently the leak was in the heat exchanger part of the transmission. This is the cylinder that has the hoses from the transmission running into it. We cannot find what this is called or where we can get one. Beaver coach sales says they don't have the slightest idea what we are talking about.
Does anyone know what this unit is called and where we can get one.
We currently have a call into Monaco.
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Tim can you get a photo of the unit; we don't have anything like you describe.
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Tim,
The unit is a liquid to liquid heat exchanger. It should be listed somewhere in their parts list as a transmission cooler or a transmission oil cooler assembly one would think. This is a link to a rectangular liquid to liquid version on the web. This is just an example, not implying this unit is appropriately sized, but it may be able to get you going on the right track with the parts folks as to what you are talking about with this photo. Hope this helps.
http://www.makcotransmissionparts.com/TDI-13680.html
Later Ed
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Tim,
I gave a call to Steve Harris the service manager at Pacific Power Products, an Allison Dealer in Kent Washington. Phone 253-854-0505. They are well familiar with these type fails. They are in the process of proactively changing out 10 of these units on fire trucks in Seattle before they fail. He indicated that the heating and cooling cycles over time will cause a crack to form which allows the fluids to mix. In the reliability field that is called a thermal cycle fail which I have some experience with in semiconductors.
He said to look closely at the unit for any PN or build identifier if you cannot get help from Navistar as a part source. Steve at Pacific Power is having high quality units built by Seakamp Engineering for his retrofits. Basically you would need to take photographs of the existing unit with dimensions, end to end, and of the ports location and sizes. They can take that info and build what you need. Basically these are a vessel with many copper tubes that the transmission fluid travels through surrounded by the antifreeze. The construction is much like a heat exchanger in a boat. Seakamps phone number is 800-753-4436. Steve indicated that the ones he had built were $750 but it will vary a bit by size and configuration. If you cannot find the current PN, or Navistar is of no help, or if the source is out of business this may be a good path to follow. Steve at Pacific Power would be happy to field your call to discuss this if needed. Hope this helps.
Later Ed
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This is what the cooler looks like. We have found one but will take a week to build and we would like to get the Coach out this week.
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Tim
That looks like a Rocore shell and tube cooler. If there are no numbers on it they can figure out by dimensions. Go to ( rocore.com ) they have a catalog there.
Steve
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Steve
Thank you, you are right it is a Rocore shell and tube cooler. Thanks to you we have one on the way. Don't know why BCS and Monaco were unable to give us any information.
The forum and all our fellow members have done it again.
Don't really know if I am happy putting in the same product that failed and ruined our transmission. Maybe we should replace it every 5 years just in case. This would be cheaper than replacing the transmission the next time the cooler fails. Seems that there is no way to tell if you have a problem until its to late.
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Ed,
does the Marquis 2000 C12/Alison transmission have a liquid to liquid heat exchanger??
I found this one that is an Allison product. http://www.makcotransmissionparts.com/TDI-13680.html
Should we be changing the core or replacing the whole unit at a certain mileage or age??
Could we remove the existing unit if it is the liquid/liquid type and replace it with a fan cooled radiator type??
Jeremy
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I too would like to isolate the 2 cooling units from each other. I spoke to an Allison dealer in Auburn Wa. (US Transmission) and he says the 3000 maybe but not the 4000. He said the heavy duty 4000 really needs the engine coolant to get the trans up to temp and then because of the torque of the higher horsepower engines it still needs the engine coolant to keep it at the cooler temps. He also said that an isolated cooler would keep the trans at a too cool temp or not cool enough. I'm trying to find someone at Allison headquarters to answer this question but have not had any luck. I'm also going to ask the transportation dept. of the school district that I work for if they can get me a phone number for Allison. Marty
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Tim, what was th mileage when your cooler failed? I am going to look at mine and see if it's the same type unit. I have had oil coolers fail before on my boats, but that was caused by salt water corrosion in one case and an "O" ring failure in the second case. One of my best friends just spent over $60,000 to rebuild two CAT marine diesels because of failures of his H20 cooled intercoolers which allowed water to be drawn into the air intake system. Unfortunately for him, he was about 100 hours out of his extended warranty. I was lucky both times mine failed, since I noticed waterin the oil on the first one and had a catastrophic oil pressure failure on the second, but was doing some testing and was watching my guages when it happened.
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Jeremy,
All Beaver coaches have a liquid to liquid transmission cooler. There are several reasons for the liquid to liquid cooler. First it is more efficient than an air cooler. The next reason is that it will keep the transmission at operating temperature regardless of the outside temperature. An air cooler that is large enough to adequately cool you transmission in hot weather, will over-cool your transmission in cold weather and drop the transmission below operating temperature. It is almost as bad for your transmission to be continuously operated at a low temperature as it is for it to be operated at a temperature than is to high. For these reasons the liquid to liquid heat exchanger is best because it will keep the transmission at the proper temperature in all weather.
As for changing the liquid to liquid cooler for preventive maintenance, that is hard to justify. The number of coolers that fail is so low that the cost of a new cooler in the thousand dollar range when you consider labor and parts (cooler, TranSynd, and coolant), can not be justified. The best thing that you can do as preventive maintenance for your transmission cooler in my opinion is to keep track of the PH level in your coolant, and change your coolant if it starts to become acidic. That will prolong the life of your entire cooling system including your transmission cooler. However some coolers will fail from metal fatigue, but low mileage ones fail almost as often as high mileage ones from my experience when it comes to metal fatigue.
Gerald
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I for one do not know the faiure rate of the water to oil units that were used in our coach. Certainly the failure mode, wether it be vibration related, corrosion related, thermal cycle related is not clear. In my conversation with Pacific Power Products they were concerned enough to proactively replace some units before failure. How effective this is and the timing of replacement would normally be related to the cause of faiure and how each of our units is used in real life. With most failure modes one size does not fit all.
What probably makes the most sense is to learn what we can and each of us make decisons based on what is shared. Nobody will know more about these units and the expected life than Rocor. Some questions come come to mind.Why do these coolers fail? Does Rocor have a more durable design that has demonstrated a significantly lower failure rate? Also based on the predominant failure mode has the unit used in our coaches been redesigned to be more durable and if so when?
On the oil cooler page there are several designs for oil to water coolers. The one at the top appears to be pretty robust and has a removable core which begs the question, does that core have a defined useful life and a recommended change frquency or is that to facilitate cleaning if the need arises? Why this design?
http://www.rocore.com/products.html
Regarding Gerald's comment on metal fatigue with low mileage units failing almost as often as high mileage units, that certainly can be true. If these are internally soldered units, how much solder is in the joint, how well all the surfaces were cleaned and fluxed, the temperature applied and if it caused brittle metallurgy. When soldering, these issues cause defects that will fail somewhat randomly over time just as Gerald observed. The other side of the coin, the one we would want to be sure does not exist, is a design issue where we are getting wearout of these coolers within the normal use life of the coach. That would be a high failure rate, without defects being involved, due to an inadequate design. If that is what we have we would need to know that and make some decisions.
Tim, if you could provide the PN for what was removed I will try and have a conversation with Rocor. What they will share may be a different story. It won't hurt to try and learn what we can. Given the high cost and the lengthy repair to replace the transmission, we would want to know if these coolers experience wearout. If it is random defects only and the cooler normally lasts multiple lifes of the coach then it is just the luck of the draw if you get a defective one and changing one preventatively would not likely improve your odds.
Later Ed
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Ed,
If I understand your post correctly, it sounds like the failure occurs at a solder joint. Assuming the cooler was not subjected to extreme operating conditions, this seems to indicate a defect related, rather than intrinsic problem. Thus, the projected failure rate would be difficult to determine unless one knew more about how the defect was introduced; e.g. batch of solder, given manufacturing line, specific period of manufacture, etc.. From the inputs on this thread, it doesn't sound like this problem has impacted many coach owners. Obviously engine hours, operating conditions on any failed units would help to determine future risk.
Steve
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Gerald,
thank you for your reply. I also see the Rocor design on their webpage that has a removable "bundle" of coolant tubes. My Yanmar engine has a very similar arrangement for the seawater cooled sealed cooling system.
Next time I change the Transynd I am going to install the Rocor intercooler with the removable tubing bundle.
The tubing could be changed at a set mileage and hopefully eliminate the possibility of a failure.
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Steve and Jeramy,
I think what we have is defect related and the extent and nature of the individual defect in a particular cooler will dictate when it would fail. The issue is we do not know for sure if we have what is refered to as a defect fail mode or a wearout fail mode in the design of the coolers. If defect mode and you replace it you may be taking a good cooler and replacing it with one with a defect in it. If we have a wearout mechanism (like a filament in a bulb has a predicatble life in hours or a tire based on tread wear and miles) then we have a need to look at the expected life of the cooler and change one before it fails. We do not have any failure insight yet, so it is too early to understand if any change of the cooler would be expected to provide a benefit.
Later Ed
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The coach had 140000 miles on it when the cooler failed. I do not know the pin, but it was a Rocore shell and tube cooler # 3-1249T, built around 2002. For the first 75000 miles the radiator had regular coolant which was than changed to longs life coolant for the reminder of the miles. The PH was checked often and was never found to be off. There was a chemical canister in the system to help maintain the proper balance, the canister was removed with the change to the long life coolant. The radiator has had a small leak for most of its life, I needed to ad a gallon of coolant about every 5000 miles.
If I am not mistaken Mike Collins also lost a transmission from a water leak, don't know if it was the cooler or not.
The cost of replacing the cooler would be around $900.00 + labor.
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Thanks for the Model info Tim. With a few calls into Racore I have reached a source who spent 20 years with Allison followed by being the rep for Rocore in the transmission cooling field. He (Dave Wheatley) had a lot of information and I will try and pass the info I gathered along.
The 1249T cooler has been around awhile and was originally designed by Stewart Warner. It is what is known as a fixed bundle design and that style is still made today. It is a set of tubes silver brazed into a brass end cap and I believe that is brazed into a steel shell. They have a wear out life that is hard to predict individually given it is a function of use conditions but they do wear out. He discussed a 5 year life but we both acknowledged that our application is not as severe mileage wise or thermal cycle wise as many. The issue with not considering a preventative change is the cost of a transmission vs the cost of a cooler. He highlighted that the actuarial tables for rebuilt Allison transmissions do not match the normal life of original units. If you can prevent this type fail your original will likely outlast a rebuilt and your coach. FYI, the original cooler was warrantied for 18 months or 100k miles which probably does not give us much insight into the useful life.
These coolers have two primary failure modes that can occur. Corrosion is one possibility. I indicated that most of us use ELC coolant and Transynd and he said that we are using the latest state of the art chemistry with very low corrosion rates, so lets consider that one a non issue. If you are using the non ELC coolant check your PH and keep it optimized with additives.
The second failure mode is thermal fatigue causing a crack. On start up the engine coolant and transmission coolant rise at different rates and as the thermostat opens and closes there is some thermal shock that is involved. The tubes must expand and contract from ambient to maybe the 220 degree range of fluids and that stresses the tube bundle. If you have a retarder, and luckily we do not, that adds an increase component of stress due to higher temperature excursions. So we have the temperature excursions of normal travel and those due to desert travel and mountain pass climbing, again all individual driving habits and travel patterns. Prediction of useful life is hard but he was clearly concerned about a tube crack due to thermal fatigue in the shell at some point. The life of the unit depends on your use and probably the best guidance we could get would be data from failures in multiple coaches (Tim has one data point). If anyone knows mileage and age of several more we may be able to use that info to come up with some logical mileage and age value to guide us. This all assumes that we do not have an early fail due to a defect in the cooler build and I would guess that we are all pretty much beyond that at this stage.
There is a better cooler design that has evolved to eliminate the thermal fatigue fail that he would recommend. There is a floating bundle design and he thought that if that design was used, he was comfortable that in our application it would last the life of the coach given that corrosion was not an issue and that the floating bundle design does not suffer the thermal fatigue failure mode. The bundle expands and contracts without restriction.
The issue is that there is not an exact bolt in conversion. He will provide us recommendations along with drawings and insight into the differences that would have to be allowed for in a conversion. They are not that major but fittings and mounting may have to have some alteration. He indicated that the thermal performance would be equal to or better for this cooler over the 1249T design. He would get to this when he returns after the 1st of the year and I will pass the info along. Maybe Gerald or anyone else into the mechanics of these things could offer up an opinion as to what would be needed to physically change over and not worry about this issue again. We will take our time and see if some logical path evolves...
Tim, I'm sorry that you are suffering through this issue. Hopefully you can find a way to have a good Christmas after all.
Later Ed
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Ed and Gerald,
So we will wait till the New Year to find out all the details of the new "floating bundle" design.
I have a Ford F250SD 4x4 6.0 diesel with one of these liquid to liquid coolers.The previous owner had a mega $$$ bill when the cooler failed at 45,000 miles !! I know the cooler has 80,000 miles on it so I am inclined to change it out for a new floatng bundle design as well as the one on my Marquis.
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Ed, Thank you for all the information and your time spent researching it. I also spoke to Pacific Power here in Kent, Wa. and they also said that changing to an air to liquid cooler was not possible for the 4000 (same as US Transmission said). They went on to say that they are recommending and are changing out coolers on firetrucks every 2-5 years depending on make and model. I'm really wondering if (in my case) I should just change it out with something newer and better to be on the safe side. Please do keep us updated.
Marty
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Marty,
I would hate to spend the money too early if it is not really necessary. What we need is some data of mileage and age for failed coolers of this type in Monaco RVs. Short of that we would have to get an educated guess from Rocore. They may have an RV cooler fail database. Tim mentioned Mike Collins, if somene knows him and could get that info, maybe that would be another datapoint.
The fire truck would have no warm up time, hard relatively short runs, and then it would be shut down again. For the miles traveled thay would have many more thermal cycles then a typical RVer having the same mileage. They also need to get to the fire and be available so they would conservatively be trying to prevent major failures while in service. 2 to 5 years seems conservative for RV folks but only the fail data will give us the best answer. I would wait and see what info comes our way in January.
If you do go ahead and replace one of the current designs with the same PN and design I would say you would be reasonably safe for the next 5 years and 100k miles. If there were a lot of RV transmission cooler fails within that range I think we would have had more bad news on the forum.
Later Ed
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Just got the coach back from Valley Power Systems and all seems to be well. We were very happy with their service and would recommend them to anyone needed Transmission work in the San Diego Area. They seem to be a well respected company, they were doing service work on fire trucks from as far away as Los Angeles.
I did pick up some more useful information while talking to the service manager. He said that the cooler on our coach was a very tight fit, installing another unit that was of a different size and shape would be a problem. He also said that 80% of the transmission failures they fix are caused from water in the fluid. It only takes 2% water to destroy a transmission. The cooling system sure seams like the weak link in the system.
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Tim, Glad you are back on the road before Christmas, that must feel good. Thanks for passing along the insight regarding space constraints and the transmission fail service managers observations. It does look like there is a common theme on that subject emerging from multiple sources. 8 out of 10 fails having a common source would warrant taking the root cause seriously.
For all Patriot and Marquis owners with C12s please send your coaches year and miles to me at ednjillb@hotmail.com if you have not had a fail. Just approximate K miles would be fine. If you have had a cooler fail or know of someone who has please let me know and send me the approximate miles and age when the fail occured.
If someone else owns a Monaco product that has a C12 drivetrain and you would like to pass your info along, that would be welcome also. Both a fail database and a database of still good coolers in the field may be useful in coming up with some life expectations. We will see what we can learn to help ourselves. Everyone have a good Christmas.
Regards Ed
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For all Patriot and Marquis owners with C12s please send your coaches year and miles to me at ednjillb@hotmail.com if you have not had a fail. Just approximate K miles would be fine. If you have had a cooler fail or know of someone who has please let me know and send me the approximate miles and age when the fail occured.
FYI, I have the data for five coaches so far. Hoping for more inputs in the next week or so. At some point I will tally up for the forum the miles, and age of any fails as well as the same data for coaches without fails to see if it will help us in any way.
Later Ed
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Our coach is a 03 Contessa with side radiator and Cummins ISL. After reading Gerald's post saying that all Beavers have a liquid to liquid cooler for the transmission I crawled under to have a look and was looking for the cylindrical cooler that failed in Tim's coach. What I found was a tall rectangular cooler housing about 5 X 5 inches square and about the height of the Cummins radiator. This box has 2 lines from the Allison attached to it and a large hose that returns to the Cummins. It is mounted adjacent to the forward edge of the Cummins radiator and is about the same height and depth.
If this is the Allison cooler does anyone else have this cooler arrangement and have any failures been had?
Any thoughts?
Paul
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Paul, we also have a Cummins (8.3C) in our '95 Patriot with a similar type of trans cooler to the one in your photo. I believe that this thread discussion relates to the coolers used only with the CAT C-12/Allison drivetrain, which are different from the ones used with Cummins engines.
We have had no failures or leaks in 60K miles (so far, so good!!!).
HTH.
Andy
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Andy,
Thanks for the info. I did not realize the thread was for the Cat C-12's only.
We are presently at 80,000+ miles and the only significant failure was the charge air cooler about 3 years ago.
Paul
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Paul,
Technically this thread is about all coaches, however since different models use different coolers, and the cooler that failed was on a C-12 equipped coach, Ed has started a database to try to determine if there is a predictable life expectancy for this particular configuration.
The part that you described in your previous question, sounds like your transmission cooler. The problem with a transmission cooler failure is that you will not know it until your transmission is damaged because the leak will be internal to the cooler. The internal cooler leak will allow coolant (50% water and 50% antifreeze) to enter the transmission, and any water in the transmission fluid will cause permanent damage quickly because the adhesive that is used for the clutch material is not waterproof.
Gerald
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Attached is a photo of my 03 Monterey with 350 cummins and rear radiator. It was delivered by Beaver Coach with an air/liquid transmission cooler that has only transmission fluid flowing through it. There is no engine coolant involved with this cooler. The 350 cummins in my coach has a direct drive fan therefore air is flowing through the radiator and transmission cooler anytime the engine is running. Monaco switched to this stand alone cooler after losing millions of dollars in the late 90,s to faulty radiators that destroyed the transmissions. The cooler is mounted on the top right side of the radiator with the charge air cooler being above the radiator. It is about 21 inches wide and 12 inched tall.
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I have the following inputs so far. Glen Perkins, Jeramy Parrett, Les Marzec, Marty Shenck, Garland Land, Phil Rodriguez, Larry Shirk, Richard Simonis, Gerald Farris, Tim Bently, Joel Weiss, and myself. If you have sent me an Email ( ednjillb@hotmail.com ) and I have missed it please resend it. My filters did over filter in some cases, and I am now watching closer for that.
If anyone knows of anyone else that has a coach with a C12 and Allison 4000 in it, and they are not included in the above list, see if you can gather the year, miles, and if they have had a cooler fail info for us and pass it along to me. Of particular interest is the data for anyone else who has had a cooler fail. If you think that there may be another owner out there that we could seek that information from let me know the contact info if you have it.
Thanks Ed
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We had a radiator failure in our 2003 Thunder. The problem was that an internal partition broke, allowing engine coolant and Transynd to mix. The fix was to replace the radiator and rebuild the transmission. Cost was $18,591.99. Monaco extended care paid all but $2,815.53. The breakdown occurred in August 2008, mileage on coach was 65055. It took almost 6 weeks to complete repairs because of the inspections required by Monaco extended care. Should I mention the 3 thousand dollar damage done by the tow truck?
Mike
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Just to recap on the transmisson cooler failure that Tim experienced, this is where we were with input from Dave Wheatley at Rocore..... skip the next four paragraphs if you have a good memory and are still up to speed on this...
These coolers have two primary failure modes that can occur. Corrosion is one possibility. I indicated that most of us use ELC coolant and Transynd and he said that we are using the latest state of the art chemistry with very low corrosion rates, so lets consider that one a non issue. If you are using the non ELC coolant check your PH and keep it optimized with additives.
The second failure mode is thermal fatigue causing a crack. On start up the engine coolant and transmission coolant rise at different rates and as the thermostat opens and closes there is some thermal shock that is involved. The tubes must expand and contract from ambient to maybe the 220 degree range of fluids and that stresses the tube bundle. If you have a retarder, and luckily we do not, that adds an increase component of stress due to higher temperature excursions. So we have the temperature excursions of normal travel and those due to desert travel and mountain pass climbing, again all individual driving habits and travel patterns. Prediction of useful life is hard but he was clearly concerned about a tube crack due to thermal fatigue in the shell at some point. The life of the unit depends on your use and probably the best guidance we could get would be data from failures in multiple coaches (Tim has one data point). If anyone knows mileage and age of several more we may be able to use that info to come up with some logical mileage and age value to guide us. This all assumes that we do not have an early fail due to a defect in the cooler build and I would guess that we are all pretty much beyond that at this stage.
There is a better cooler design that has evolved to eliminate the thermal fatigue fail that he would recommend. There is a floating bundle design and he thought that if that design was used, he was comfortable that in our application it would last the life of the coach given that corrosion was not an issue and that the floating bundle design does not suffer the thermal fatigue failure mode. The bundle expands and contracts without restriction.
The issue is that there is not an exact bolt in conversion. He will provide us recommendations along with drawings and insight into the differences that would have to be allowed for in a conversion. They are not that major but fittings and mounting may have to have some alteration. He indicated that the thermal performance would be equal to or better for this cooler over the 1249T design. He would get to this when he returns after the 1st of the year and I will pass the info along. Maybe Gerald or anyone else into the mechanics of these things could offer up an opinion as to what would be needed to physically change over and not worry about this issue again. We will take our time and see if some logical path evolves...
New News...
First regarding the database of mileage vs failure, we basically have about 15 coaches ranging in mileage from 32k to 223k miles. Tim has had the single failure with the exception of several coaches that I did not include in our database, which had the transmission cooler built into the main radiator assembly. That design was prone to failure at a higher rate and fewer miles than the 1249T.
Usually in this kind of situation when you are life testing for wearout, you would thermal cycle assemblies beyond the normal use to accelerate the failure until you reached what is known as the T50 point which is where half the units in the sample test have failed. Then you would model the useful life to assure that either the unit lasts beyond the normal use lifetime or define when you would replace a unit before it would fail. We do not have that kind of data and with the information in our database having just one fail at 140k miles, what we can predict and conclude is limited. It would be in each of our best interests to make a personal decision regarding how conservative you would want to be regarding this issue. I think being conservative would mean changing your cooler unit out before the first known fail would have occured, maybe considering cooler change in the 120K mile range. There are just three coaches in our database beyond the 140K miles where Tim had his fail, one at 145k, one at 151k, and Lamar at 223K miles. Obviously units can last longer than Tim's did, they will not all fail at the same time but the way things work with fatigue and cracking is the more times you heat and cool the cooler the closer you are to when it will fail. In time we may see a cooler fail earlier than Tim's did, but until we see that, the 120K miles seems like a reasonable approach as to when you would consider your options. If the failure was not such an expensive and difficult situation to deal with we would not be taking such a hard look at this. So that is my own personal perspective on this cooler issue for now...
Dave Wheatley at Rocore has been dealing with some health issues so things have gone slower than expected. I did get the drawings of the current cooler design for the 1249T which I have attached. Dave was to also research alternatives that use the floating bundle design which is allowed to expand and contract without the metal stress issue and therefor is not prone to this failure mode. The issue we would have had to deal with a change in configuration in a tight space.
Dave and I dicussed Rocore making a floating bundle drop in replacement for the 1249T and I am pleased to report that they had drawings for that unit and he got permission to have that unit become an active design. I do not have price and availability information yet but I will pass that info along when I get it. If you consider changing out your cooler this would be the more reliable design.
Hope this all helps along the way in preventing someone else from having to go through what Tim did. Sorry this got so long...
Later Ed
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Thank you Ed for the time and effort you have put into compiling the data and the research for a possible good outcome.
Marty
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Just to let everyone know that the ROCORE 3-1249T cooler is also installed with 3126 Cat engines on the Magnum chassis. I have one of those units on my 2002 Patriot... With this concern about failure, I am trying to find another heat-exhanger for replacing the ROCORE unit. Ed Buker and I just spoke at lenght on the phone about this issue. Will keep everyone posted on our findings. I should note, the ROCORE cooler may not be as prone to failure in the 3126 application because of not see the extreme heat cycle that people see w/C12s.
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Karl,
Is yours a side or rear mount radiator?
Steve
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Steve,
It is a rear mount radiator.
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I know that folks are concerned about the cooler issue and I want to be sure that we all take our time here. I saw nothing in the data that would indicate what I would call an emergency issue on anyones part, where a cooler change is needed immediately.
The expense of a fail is of great concern but I think what we are looking for is a drop in design that is a best of breed cooler that eliminates the root cause of the stress crack fail in the current design. Getting this right in the end will serve us best. I hope to have more info from Rocore next week on the alternative design. If there are other good designs that will work as a replacement for a 1249T and someone is out looking keep us informed...
Later Ed
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Karl, C12 drivers,
I'm a bit confused re engine / tranny temps. Under normal conditions I was under the impression the side radiator units, including C12s would run cooler and maintain a more consistent temperature than a rear radiator unit. E.G. my rear radiator 3126B runs about 194 engine temp when ambient temps are <85 and I'm not pulling a hill. If I start climbing or ambients get to 95+, engine temps start climbing. On a long hill in the summer, I'll run up to 205-212, even when keeping rpm up to 2000. Tranny temps lag engine temps be a few degrees normally. As soon as I am able to unload the engine, temps drop down to the mid 190s. So, I think I see quite a bit temperature variation, due to both the marginal power to weight ratio and the less than effective air flow into the radiator. BTW, I've got 125K miles on it and am not running ELC or Transynd. (Plan to change both over at next service interval).
Do C12s see these temps and or variations?
Thx, Steve
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Steve,
C-12 equipped coaches rarely have that much operating temperature change. The side radiators cool more effectively than the rear radiators do, and the engine rarely needs to operate at full power so the engine operating temperature on a C-12 normally stays around 185 to 190.
Gerald
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Gerald,
Thanks! That then seems to reinforce the view that the cooler problem is a defect related issue. Otherwise it would seem to follow that the smaller engine, rear radiator units would be considerably more prone to exhibit the failure.
Steve
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Steve,
I am using Transynd and Cat ELC. The Alison transmission temp stays around 175 deg F .It may rise to 185 under severe load as it did here in Western Mexico running from Guadalajara across the Serra Madres down to Puerto Vallarta. The C12 ELC temp stays around 183 deg F .It rose to a max of 200 deg F on this trip. These are the most severe conditions I have even driven ;hills of 10 miles at a 10% incline are common......sometimes steeper. My coach has 90,000 miles on it. I will be changing out the Rocore liquid cooler as soon as the floating bundle design is available.
FYI....The Yanmar 4JHE diesel in my sailboat has a heat exchanger with a floating bundle design. It is made of cast bronze and the bundle is stainless steel. The end caps are sealed by huge O rings.
jeremy
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Steve,
Actually this failure mode is a wearout issue and not a defect issue. The fail is a stress crack in metal due to fatigue, not really a defect site. The worst stress of expansion and contraction against the fixed bundle containment is from a cold start up to normal operating temperature range, that is followed by many small expansions and contractions during driving, then the more severe cool down contraction cycle. At some point all of these units would fail with enough cycles due to the stresses involved. The fail point in any individual cooler will be the weakest point. Some may last 500k miles and some just 140K or possibly less in our RV use situation. The fire engine use case is a worst case with many more severe heating and cooling cycles for the given miles they drive. I can see why those units are being changed preventatively.
This fail is much like bending a piece of copper pipe back and forth until it breaks....that is basically metal fatigue. The alternate floating bundle design is allowed to expand and contract without restriction so the metal stress is eliminated. If the O ring sealing system on the floating bundle is fault free by design then this configuration has elimintated the stress cracking fail and should be a more worry free design. Hope this helps.
Later Ed
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Ed, I found this Rocore design on their product page. Last time I looked it wasnt there. Is it new?
This design is very simiar to my Yanmar diesel engine intercooler design. http://www.rocore.com/products.html
http://www.rocore.com/docs/floating.pdf
If so,which one would be a good fit for the C12 ??
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Not sure that I fully understand the new design data sheet. The 3000 and 4000 w/o retarder are not even addressed in these data sheets. Does that assume that this floating bundle design would only apply to 3000/4000 with retarder? I may be very confused, don't we all have exhaust (pacbrake) brake or internal engine (Jake) brake systems? Do any of us have transmission retarders?
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Jeremy,
Rocore has made a floating bundle cooler for some time. The problem has been that they have not made a drop in replacement version for the 1249T fixed bundle design. What we learned is that there was a design for one but it had not been released. My contact was able to get the design released within Rocore but because of some health issues has not been able to provide cost and availability yet. I do not think it is reflected yet in the link Jeremy provided. He indicated that he would try and get us more info this week but so far I have not heard from him. I will post as soon as I do.
Karl,
We do not have retarders and if we did that that could require a second cooler. With the floating bundle Rocore accomplishes retarder cooling by stacking two cooler sections in series with a spacer in between the sections. The antifreeze flows through both but the oil cooling is seperate. They also have a reversing design where the antifreeze flows from one end of the cooler through a bundle of pipes that then loops back to the same end through that same bundle. Our design has an entry and exit for antifreeze on opposite ends so we would not want that reversing bundle. So ours would be a single bundle non reversing cooler like the configuration of the fixed bundle 1249T. There are some photos and good cutaway views of a single and stacked version in this MCI service bulletin. More info here than needed...
http://service.mcicoach.com/ServiceInfo/ServiceBulletins.nsf/656d2ee39f727cd386256c1e0042b975/1896d1ccc41362e286256fd00055be3d/$FILE/2898B.pdf
Later Ed
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This is the latest from my contact at Rocore. Dave asked how many units we would need initally and I told him 10 units to get the ball rolling.....that is not a commitement to buy....
Ed,
Thanks so much for your patience! As of Monday, I am back among the living and in the office, slowly getting somewhat caught up.
Engineering has not yet completed the release process, but I have attached a concept drawing for you (5-7055B).
The production design will include the same type of mounting brackets as used with 3-1249T.
How many units do you think would initially be required?
Best regards,
Dave Wheatley
Shell & Tube Product Manager / Sr. Sales Engineer
ROCORE
Things are moving slowly but at least we have a drawing now. There are some differences that should be noted.
-The oil lines are spaced 13.5 inches apart instead of 12 inches. Overall length is literally the same and the coolant inlets and outlets on both units are 3 inches.
-The diameter of the replacement would be 5.5 inch vs 5 inch for the 1249T.
-I am not sure if the oil lines would use the same thread/size arrangement in both cases. Those knowing hydraulic lines should comment.
The unit seems to have end caps that are held on place by retainer rings and not bolted like the other drawing.
I think it would fit but may require redrilling the current mounting plate if the U bolts are slightly different. The hydraulic oil lines may need replacement, not really sure.
I asked Dave what the approximate price would be and when this unit might possibly be available. I'm sure things will continue to move slowly given our volume demand for this cooler is not significant. We will keep our fingers crossed that things continue to move forward.
Later Ed
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Latest news on the floating bundle drop in for the 1249T from Rocor. Not a lot of news.... these wheels are turning slow but at least they still seem to be turning....keep you posted as I learn anything new.
Ed,
Sorry for the way this has drug on, but Engrg is still working out some design details.
I hope to have a price estimate for you early next week.
Best regards,
Dave Wheatley
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Happy to Pass along the Following:
We have finally reached the end of our quest for an (almost) drop in Rocore floating bundle design replacement for the 3-1249T. The 50755B option in the previous drawing was not feasable for the expected volume of sales due to a $50K cost of tooling up for this unit.
Dave Wheatley continued to look at options and has been successful in making available a floating bundle cooler as a replacement for the 3-1249T. The number will be 5-7063E. It will have 3" ports for the coolant flow, the same threaded ports for oil flow as the existing 1249T but they are spaced at 14.5 inches instead of 12 inches apart. The overall length of the new cooler is 19.98 inches vs 19.6 for the original cooler. The U bolt leg spacing for the old cooler was 5.5 inches and the new one is 5 inches so the mounting plate may need to have a several holes drilled in it to match the U bolt spacing. From what I see this looks like a very usable design dimensionally for our current configuration. This design has been available for 5 years with a 2.5 inch coolant port. Our design change will just require a new version of end cap core assembly with larger coolant ports cutting the start up costs.
Knowing that this design had 5 years of history I asked about the floating bundle field performance regarding fatigue failures and he wrote:
Ed,
We have used this design on other major MH chassis for over 6 years plus refuse trucks for about same time with no issues with thermal fatigue failures. In that regard, it is truly superior to a fixed bundle design.
Let’s don’t get started on that book! I could add a few chapters myself.
Best regards,
Dave Wheatley
The 5-7063E Design:
The unit has an aluminum cast and machined outer shell. The shell has a groove for an O ring machined at each end as well as a groove for a retainer spring clip. The floating bundle is 16.3 inches long vs 14.1 inches in the 1249T so they have been more efficient with interior space getting higher heat transfer with longer fluid residence time in the tube. This offsets the smaller diameter bundle. The end caps are soldered to the bundle so that is a fully sealed assembly and the assembly then floats against the O ring as a seal. If there ever was an O ring seal issue there is no antifreeze to oil interface at an oring, it would just seep by the O ring to the exterior. I was concerned and wanted to be sure that we would not trade one issue for another. Dave also mentioned that the O rings to some extent offer a small amount of vibration isolation from the housing to the bundle which helps with fatigue issues. This looks like a good design, certainly elminating the main fatigue failure mode that we have now.
Cooling:
I had Dave run cooling models for the 1249T vs the 5-7063E design. He used a C13 525HP and a 4000 Allison given the C12 data was not redily available online from Cat any more regarding coolant flow. All things being equal the new cooler design should cool abot 4% better than the current design and passed the critical temperature limits set by Allison for the 525HP C13 version so I think cooling performance should be very similar to our current configuration. Dave was later able to get coolant flow information for the C12 from a Cat distributor and confirm the calculations are acceptable. From my perspective we had existing history of good cooling performance from the current 1249T cooler, the new version being as good, should be fine.
Cut and Pasted This Pricing and Availability Note From Dave:
Ed,
After much searching and complete inability of CAT Factory Tech service to supply coolant flow data (even with your engine SN),
I was able to find a CAT distributor that was willing to actually look for the data.
According to the data sheets referencing your SN, the coolant flow at “EVAL SPD” (assume that means rated speed of 1800rpm) is
101 gpm. The coolant flow at “PT + 100” (peak torque + 100, or 1300 rpm) is 72 gpm.
So, it would appear that you should have at least 100gpm at 85%CE, and my predicted temps should be valid.
Regarding current pricing, the following quantity breaks would apply to cover cost of new 3” end caps and tooling:
PN Min Qty Price
5-7063E 1-pc $2,025.00
5-7063E 5-pcs $ 920.00
5-7063E 10-pcs $ 775.00
Quoted prices do not cover freight. These parts would ship from our Burkesville, KY plant.
Best regards,
Dave Wheatley
In Conclusion...
Given an on the road failure would come without warning and cost in the $10,000 or more dollar range, each of us should do some personal soul searching here and decide what is right for you. If you have a 1249T cooler in your chassis with a C12 or a lower HP engine configuration that uses the 1249T this new design would be a far superior choice. If there are BAC members considering this preventative cooler change option it would be good to get together and form an order up given the pricing advantage. I know that anyone trying to go it alone here faces too high a cost.
If you do have a fail on the road as it stands now all that would be available would be the 1249T without some product stream being generated so now is the time to consider this option even if you wait to have it installed. If there is any interest let me know in this thread or by Email if not a BAC member (ednjillb@hotmail.com) and I will contact Dave at some point after we see where we stand....
Later Ed
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Ed, What kind of a warranty would there be on these new coolers? If we as a group could come up with the 10 members to purchase them at that price count me in as one. I can swallow that a lot easier than $10,000-$15,000.
Thanks for the time you have and are putting in to this.
Marty
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I think the warranty is 1 year or 100k miles but I will ask. The issue is it just covers the part, but I believe that is customary for this type unit regardless of who makes it.
If you plan on staying in motorhoming for the long haul, you would be hard pressed today to find a nicer coach then one of our Beavers. They just do not make coaches like these anymore unless you can afford something like a new Foretravel. I think if you are staying in, then it makes sense to change the cooler at your convience sooner rather than later. Given this new design you should never face having to change it again. If you have 50K miles and plan on selling in the next couple of years then probably not.
I started looking at this problem because I could not imagine being on the road and facing what Tim went through. My house was broken into last year and robbed of family jewelry. I put the alarm system in after that....human nature.
Later Ed
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Ed
Thanks for all the work on this, it's been a great help. Our transmission and cooler replacement cost us a little over $10,000 and I will deffently be looking to replace the old style cooler I got in a few years. Maybe we could get Beaver Coach sales to do a group at a reasonable cost. I will forward a link to this thread so they will know what is going on.
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Tim,
That is a good idea. They should not be difficult to retrofit given the 7063E will be so close dimensionally to the current 1249T. It would be nice if they stocked some units given the trust they have with the Beaver coach owners already. I am attaching a drawing of the 7063C that I have. The 7063E will be the version that we would use with the 3 inch coolant ports. Hopefully there will be a way to make it available. It would not be in anyones best interest to keep buying the 1249T which is what is happening today...
Later Ed
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Marty,
I checked with my source at Rocore and the warranty is 12months or 100K miles, whatever comes first. Pretty standard warranty verbage...
Later Ed
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Thank you Ed.
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Hi ED,
Any idea on order/production status? Do we deal with the factory direct or should we place orders through BAC ??
Thanks ,Jeremy