Transmission fluid

[Jeremy Parrett]

Does anyone know what transmission fluid was put in the Alison 6 speed transmission from the factory??
  We have a 2000 Marquis Amethyst with the Caterpillar C12 455 HP engine?  

[Edward Buker]

At that time it would most likely have been Dexron 3. That fluid was available until around 2005. Since then, the Dexron transmission fluids have continued to undergo composition changes, and is now up to Dexron 6. If your transmission has had fluid changes in its life, but has not been converted to TranSynd or another TES 295 approved fluid, then you probably have a mix of multiple generations of Dexron in it.

This is the current list of the approved fluids from Allison.

http://www.allisontransmission.com/service/autoapp/172/viewpage.jsp?ThisPage=3

I do not like the cost of conversion, but I believe it is the right thing to do, given the cost of these transmissions. Once you have done two changes of the fluid and filters, you can go onto an extended maintenance schedule for Synthetics.

Later Ed

[Jeremy Parrett]

Hi Ed,
  thanks for the reply. We have changed to Transynd TES 295. It was spendy ($75 per gallon)but apparently we are now good for 150,000 miles on the fluid and 75,000 miles on both filters.  I would recommend The South Coast RV Service in Chula Vista.CA 91911 and  Mike the owner . Chris ,a very polite young mechanic,who serviced the transmission also fixed the weeping hydraulic hoses that lean on the Midland Grau air dessicator mounting bracket. The hose clamp was loose.This had caused a tar sands effect over the whole area by the dessicator mounting but never showed up as a leak on the ground. The hoses could have chafed through eventually but now with chafe protectors on them both this has been avoided.
 I did not read that I need to change the TES 295 twice to go on the extended maintenance schedule. The transmission was flushed and then filled with TES 295.
The Cat 12 455hp engine has never run so smooth. I have 70,000 miles on the coach and I am sure the ATF was original .  No points to the previous owner !!!
The difference in the way the engine now feels and runs is amazing. Idle RPM is up from 600 to 700 rpm. ......gotta be a reason for that.

[Edward Buker]

Thanks for the pointer on the hoses that chafe on the Midland Dryer. I'll check that out.

If your conversion just included a drain, filter changes, and a fill then it will take two changes according to Allison's guidelines. If they actually pulled a cooler hose and flushed the old fluid (I understand that Allison does not recommend this technique) and fully replaced all of it then you would be good to the new schedule. You could have the fluid tested once based on the old Dexron change schedule just to be sure all was well.

Glad you are running so good. I also love my Cat C12, it is a remarkable piece of machinery.
later Ed

[Jeremy Parrett]

Hi Ed,
  They charged me for 7 gallons of TES 295 . I believe that is just a refill . The complete system holds much more. So how long do you think I need to run before the second change???  Going to Baja,Cabo San Lucas  on the 27th Jan. Maybe I should do the second change on our return to the US in April??   jeremy

[Richard And Babs Ames]

We went from Dexron to Transynd and immediately got a 15 degree decrease in transmission temperature. As long as the fluid stays clean it will last many years.

[LarryNCarolynShirk]

A mechanic who knows Allison transmissions, should be able to change both filters and loose only about one gallon of fluid.  If he lost 7 gallons, I think I would look for another mechanic.  That is too expensive.

Larry

[Jeremy Parrett]

I understand the mechanic just drained the transmission case. He did not drain the cooler and the lines. I was expecting them to drain ALL the Dexron ;hence my question to Ed re having to do this all over again at some point down the road.

[Marty and Suzie Schenck]

Larry, When I change the ATF on my 4000 Allison with a filter change it takes 27-28 quarts. What gets me is that he was charged $75.00 a gallon. Thats just wrong. Transynd at the Navastar and Frieghtliner dealers here in the puget Sound area are $42-$60. range.
Marty

[Jeremy Parrett]

I agree that we paid a premium price for the Transynd. However, the S&H to the California  RV dealer did make up some of the difference,plus here in CA there are big disposal costs for all things automotive !!
 Ed, I assume the next transmission oil change will also be a regular service drain with filter change. This I assume will have diluted the remaining Dexron 3 to negligible amounts to qualify for the Alison extended warranty??
Thanks again for eveyone's valuable input.  
 On Saturday we are having the hydraulic fluid drained from the tank;a new filter installed and the tank refilled with 20 quarts of fresh  Dexron 3 . With 71,000 miles on the coach I expect this also is the first time this has been done !!!!!  
After the trip to Mexico I will be changing the differential oil as well as the axle lubricant. This will put my service records for all the lubricants we use on a level playing field.

[Edward Buker]

Jeramy,

The second change of the TranSynd by drain and refill gets you to about 90% replacement rate of the Dexron and Allison considers that acceptable to get to the extended service intervals. The interval you would follow until then is 25K miles or 12 months per the attached literature.(check it to be sure) I would not have a concern about 12 to 24 months if the mileage was contained to the 25K. There are high capacity filters called for which I'm sure your shop was aware of and used.

http://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=SA5429EN.pdf

When your second change is done you may never have to change it again. You would follow the filter change intervals and have fluid analysis done with the filter changes to guide you. I'm sure that there is benefits to the transmission with
just the first change to TES 295 that you have done. You may want to label your dipstick "TranSynd Only" or "TES 295 only" now that you have started down that path if your shop did not already do that for you.

The price was a little steep for the fluid, but trusting who does the work sometimes is priceless today.....

later Ed

[Jeremy Parrett]

Hello  Ed,
   We will get the fluid changed when we get to Bend,Oregon in May.   By then we will have 3500 miles on the coach.     Thanks for your input.    jeremy

[Edward Buker]

Jeremy,

There is no real need to change it that soon unless you just want to finish your conversion. The guideline is 25K miles and 12 months after your first fluid change to TranSynd or equivalent. The fact that you did not get all the old Dexron out is a normal occurrence with any Allison transmission drain and change and is factored into their service interval requirements.

later Ed

[Jeremy Parrett]

Thanks Ed.
   I know the Cat is running way better.  We leave for Baja Mexico on the 27th.  I am eager to see the diesel mileage improvement.   J&J