Switch out 1989 tranny for a 6-speed?

[Ted Couch]

We have a 1989 Beaver Marquis with about 69,000 miles. The tranny does its job but going up a hill of any magnatude we need a while to make it up. Wondering if anyone has done a 6-speed in an older Beaver? We live in the Vancouver WA Portland OR area. Would the cost and possible complications make it a bad idea?

Ted Couch

[Gerald Farris]

Ted,
The transmission exchange that you suggested will be expensive, and it will not solve your problem by itself. In the 6-speed Allison, fifth and sixth gears are overdrive to reduce engine RPMs for less engine wear and better fuel economy. So a 6-speed will not pull a hill any better than a 4-speed. However the overdrives in the 6-speed will allow you to change to a lower gear ratio differential that will help your hill climbing some.

The main problem in hill climbing with a 90 Marquis is the 3208 engine. It produces about 1/2 of the torque that my C 12 does. So if you want to go uphill faster you may try better intercooling, more boost, or other engine modifications, but it would probably be cost effective to trade-up to a later model coach with a high torque engine. The C 12 first came out in the 97 Marquis.

Gerald

[Ted Couch]

Thanks for your input Gerald. I appreciate it. Great food for thought... :-/

Ted

[Bruce Benson]

Ted

I have a quote for a new Allison 4000 from Stuart and Stevenson (an Allison Distributer) for $36,000 installed, if that helps you at all with your thinking.  In agreement with Gerald, you would additionally be looking at some rear end changes as well.  

[Edward Buker]

My understanding is that there were several older Beaver Marquis Coaches (1992 or so vintage) that had the engine and transmissons replaced with a more modern Cat engine and Allison transmission. As I understand it several of these upgrades were done by Beaver in Bend Oregon. I did see one of these coaches for sale in an ad several years back from California Coach Company. They may recall the coach and perhaps have some insight or the name of the owner. I'm sure it is an expensive proposition but the chassis and body condition and quality may warrant the investment in an upgrade. Depends on your attachment to the coach.

Without a more modern engine and a well coupled transmission my guess is that you would be less than satisfied that the expense was warrented by the very marginal improvement.

Regards Ed

http://www.californiacoachcompany.com/inventory_avail.asp

Found more info, coach is visible on the sold portion of the website.

Description: This top of the line Marquis has been fitted with a 330H.P. 3126 Caterpillar electronic diesel and an Allison 6 speed transmission. The installation was done by Beaver in Bend, Oregon. This wonderful Marquis had a list price of over $280K in 1988! This well made coach features solid walnut cabinetry, corian counters, a private bath area, an ice maker, a gas range, big refrigerator, and microwave, full Zip Dee awnings, This coach is in very nice condition throughout, and with a fresh modern engine and transmission how could you go wrong? Please contact us for more information on this fine, affordable coach.

[Richard And Babs Ames]

Our 1997 Patirot has the above engine and transmission and weights thousands of lbs less is still not a much of a climber. Going th a rally in Lake Placid,  New York I felt like a turtle behind two rabbits that did not stop to smell the roses. Reason is 830 lbs of torque compared to 1500 plus.  

[Peter and Connie Bradish]

 The question is why do you want to go up hills faster?
 We have a 93 Contessa with 250 HP and 660 ft/lb of torque. We tow a Jeep Liberty which weighs 4000 lbs. Yes, we are slow up hills/mt passes sometimes. 25-30 mph on some up hill climbs. We talked to our mechanic about it. He told us about costs, etc. He also said, "Is there a hill you haven't climbed?" We said, "Well, no." (this includes Eisenhower Pass in CO)  He said, "Well ?-?-?-"
 Ever since then we have just been patient on hills/mt passes and taken our time in the lane with the slow trucks. We now have 220,000 miles (49 US states & all Canadian provinces except Nunavut) on our coach and have loved every minute of it, even the slow climb on steep hills.
 I would suggest if you want to go faster you will need to buy a newer Beaver. The cost to upgrade in your present 89 would be prohibitive and for what? 55 instead of 30 to 45 up a hill? Again why do you want to go faster up the hills? When you answer that question, you can make decisions about what to do with respect to your coach.

[Bill Sprague]

The question is why do you want to go up hills faster?

I challenged a friend with a 455 Cat in his Patriot.  We were going to drive over three 6% grades between Yakima, WA and Ellensburg.  Our coaches weigh about the same but his motor is a lot bigger.   The cruise controls were set at 60 and we agreed to not exceed the speed limit downhill.  He beat me by less than two minutes. Our total drive time that day was about 2 hours.  

Even in the West we drive up hill for only a few minutes in each trip, so going faster uphill is insignificant in the passage of a travel day.

Another friend, with a Thunder, had an even bigger engine in a coach with the same floor plan as ours.  His bigger engine needed a bigger transmission.  That called for a tag to support the extra engine and transmission weight.  Now all the framework needed to be stronger and heavier.  And, the engine needed a big cooling fan to keep from overheating while it pushed 45,000 pounds up hills.  Altogether his coach weighed about 12,000 more than mine.  The result was his similar floor plan rolled down the road at about 6.5 mpg while mine gets 8.1!  Yes, he got up the hills a little quicker but Wally was nice, and polite enough, to insist on following, not leading, up the hills.  He only chose to "embarrass" my little engine once, for the fun of it, on the long road from Prineville to Newfoundland.  I wish Wally was still here to do that trip again.

[Edward Buker]

I owned a 1989 beaver Contessa with a Cat 3208 Turbo with approx 250 HP, 485 Ft lbs of torque at 1400RPMs, and a 4 speed Allison in it for my last coach. I would travel at 62MPH at about 2400 RPMs. I now own a 2002 Marquis non Tag axle 505Hp with 1550Ft Lbs of Torque at 1200RPMs and a 6 speed Allison. I now travel at 65MPH at 1450RPMs.

I understand the question and the problem with the underpowered Cat 3208 in the early Beaver Coaches. It is not just a matter of uphill speed and a couple of minutes. It is a matter of losing gearing, running 2400-2700 RPMs in 2nd gear at 30MPH, worrying about cooling airflow as the fluid temperatures rise, the safety issue of possibly being rear ended, and an engine running as hard as it can for very long periods of time with tremendous heat build up. It just keeps you on edge worrying if everything will stay together. There was always a debate with a slower truck ahead of you if I dare go into the left lane at 30MPH or lose more speed behind a truck doing 20. That was part of the life experience in an older Beaver, one might say part of the adventure. When you crested a pass you had to engage an exhaust brake and use 3rd gear to hold you back from the ride of your life...

The new Marquis with the Cat C12 and the Allison 6 speed are electronically integrated seamlessly and there is no worry at all about the passes. I travel mostly at 65 MPH and the coach moves effortlessly at this speed and the longest Interstate passes barely put a dent in the speed if at all. Some passes I crest at 65 and need to be careful to pull the cruise control off before I summit otherwise I have to brake in conjunction with setting the jake brake. Just no worry at all during the climbs and a dream to drive. Sometimes when I stopped after climbing a pass the 3208 heat would be extreme being emitting from the engine compartment and it is a non issue at all with the C12. Mileage wise I averaged 8.8MPG with my 36ft 1989 Contessa traveling at 62MPH and I now average 8.6MPG with the 2002 Marquis 40ft non tag traveling at 65MPH. I am very impressed with the newer coaches performance and see it as a world of difference. I am running Michelin XZA2 Energy tires that are supposed to give you about .2MPG better than standard tires on the new coach. I thought my mileage would be worse than it is with the C12 but that is an accurate average for about 8k miles of travel.

The engine capabilities have now evolved to better match the coach and in my case it is a dramatic change for the better.

Later Ed

[Don Hircock]

"I travel mostly at 65 MPH and the coach moves effortlessly at this speed and the longest Interstate passes barely put a dent in the speed if at all."

I'm impressed Edward, I presume with your above reference that means you have been eastbound I-70 to Denver over Vail Pass and through Eisenhower Tunnel (actually Edwin Johnson Tunnel Eastbound) and maintained that speed.  That sure beats my C-9.  I'm not unhappy with it at 35 mph towards the top, its just the surge I get in it and just told to live with after several diagnosis stops.
Gerald will fix that problem for me, we've never talked about that one that I've put up with for the past 3 years.  

Happy
Trails

[Joel Ashley]

I'm certainly happy with our almost over-powered 36' Monterey with the 400HP C9 and Allison 6, towing our 4300 lb Explorer.  On my last trip from Portland to Hagerman, ID, about 500+ miles of mostly I-84, I did something I don't usually do.  I determined to try for maximum fuel efficiency, and I know that the cruise control system has a much steadier foot than I do, so I put it to work.  From the start I set the cruise at 57mph, just above truck speed in the right lane, and tried to stay there.  Where I had to pass, I took my time and tried to do it without changing the cruise control or stomping on the throttle.  Where the speed "limit" went up, I tried to cruise at the posted truck speed.

Only rarely did I override the cruise, say up a steep grade somewhere or to pass without holding up left lane speed-a-holics, or to engage the exhaust brake down a long hill.  Normally we would stop in La Grande or Baker City to refuel and eat, and I normally have 1/2 tank at that half-way mark.  I was flabbergasted as we reached Pendleton and then Meacham, and my guage and Alladin indicated I was no where near down to a half tank.  In fact, I didn't hit that point until around the air base at Mountain Home, east of Boise.   The Idaho section required a bump up in speed to be safe, due to the higher posted limits.  Nevertheless, it was an awakening when I finally filled the tank in Twin Falls, and calculated 9.6 mpg.  Keep in mind that this CAT had only 8000 miles on it at the time.  Imagine the numbers when it gets broken in.

In dozens of identical trips over the decades, in cars and our old gas motor home, it took at least 9 hours, which included rest stops, refueling, and meal stops.  I was so comfortable on this trip, that I drove the entire way non-stop.  8 hours.  My take is that at the moderate speeds I never got stressed, and could even actually enjoy the country as we went by.  I've always found that hard to do at 65-70 mph.  The comfortable ride probably helped, as did no work for my right foot.  I could have switched driving with the Missus, but was never tired until a half hour after we got past Boise's more stressful freeway section and darkness fell.

The cruise control is probably the number one contributor to the good mileage - set it and pretty much forget it, except the occasional exhaust brake or manual shift on hills or to pass.  Minimize the amount of time your foot is on the throttle or brake.  Secondly, be patient and enjoy the trip, even if its one you've taken dozens of times.  Stay at or just above the posted truck speed;  65 to 75 mph may be normal in Texas, Wyoming, or Montana, etc., but if you're serious about minimizing fuel use, for yourself and for the country's sake, then make the conscious, deliberate decision to slow down.  Our most enjoyable trips are on good state and county "backroads" at 40-45 mph.  Anything over 60 on a freeway with all the nuts is hardly enjoyable.  Or fuel efficient.

-Joel

Sorry Ted- we kinda got off-topic. :-/

[Edward Buker]

Don, I have not done the pass on I70 west of Denver in this coach and that pass would probably be a challenge to hold speed on. It would be interesting to see what speed the coach would hold. From my recollection I would guess that 62-65MPH would be a very tall order. I have done the passes on I90 out of Seattle going to Cour d'Alene. Also the climbs on I5 going from Oregon into CA heading toward Sacramento. Those did not pose a speed problem. There have been other passes, just hard to recall where. A couple of other things to note. My coach is lightly loaded with water and waste when I travel, I have a light tow, a Honda Accord, my coach is shorter than the non tag 2000 and 2001 versions which saves some weight, and I run 115PSI cold pressure in all tires which have reduced rolling resistance by design.  

This coach does not shift into high gear until I reach 60MPH and I have tried traveling at 62 vs 65 MPH and have not observed any discernable mileage difference. There is probably a tenth or two MPG difference but I have not consistently seen it. I primarily use the economy mode on the transmission selector and the cruise control for travel. I have considered a slower speed (57MPH or so) for improved mileage but thought that traveling in 5th gear would be counterproductive. It would seem that the gearing has me traveling above 60MPH just to maintain top gear.

I am impressed with the Cat C12 and the Allison 4000, seems like a marriage made in RV heaven for this coach.
Later Ed

[Joel Ashley]

Thanks for the reminder, Ed.  I forgot to mention I try to stay in Economy Mode most of the time also.  I've wondered about the 5th to 6th shift myself, and wished that point was closer to 55 mph.  There was some discussion in 2007 about Allison reprogramming (lowering) the shift point, but I don't think they did.  That might satiate concerned owners like me, but their tests probably indicate that the benefit, if any, isn't as substantial as you and I might think. As I recall the shift point is around 63?   The trip I referred to in my previous post was 85% in 5th gear netting over 9 mpg.  Dare I make the next one at 65 in 6th just to see?  I dunno;  maybe at night, but otherwise I like to smell roses  .

-Joel