Allison Transmission

GaDawgFan · 04-16-2007, 07:33 AM

I am still very new to all of this as I recently purchased my first motor home. The motorhome is equiped with the 6-speed allison transmision. Other that pushing the Drive, Neutral, or Reverse buttons, I know nothing about this thing. Is the LED display always suppose to display the number 6? Also, should I also be useing this pad to manually down shift when in the mountains? The family and I recently took the motorhome from Atlanta up to Unicoi state park (above Helen), and while not extremely hilly, I was rather disappointed in the performance. I should note that I tow a 2002 Saturn L-200. I know as I become more comfortable I will be venturing further into the mountains via the Blue Ridge parkway and know that there are much steeper grades out there. I would just like to hear from others on how to best use operate this transmission. The coach itself has less that 50,000 miles on it and because I cannot find a record of transmission service from the previous owner, I am going to get it in for transmission service next week. I would appreciate any suggestions.

GaDawgFan · 04-16-2007, 07:33 AM

I am still very new to all of this as I recently purchased my first motor home. The motorhome is equiped with the 6-speed allison transmision. Other that pushing the Drive, Neutral, or Reverse buttons, I know nothing about this thing. Is the LED display always suppose to display the number 6? Also, should I also be useing this pad to manually down shift when in the mountains? The family and I recently took the motorhome from Atlanta up to Unicoi state park (above Helen), and while not extremely hilly, I was rather disappointed in the performance. I should note that I tow a 2002 Saturn L-200. I know as I become more comfortable I will be venturing further into the mountains via the Blue Ridge parkway and know that there are much steeper grades out there. I would just like to hear from others on how to best use operate this transmission. The coach itself has less that 50,000 miles on it and because I cannot find a record of transmission service from the previous owner, I am going to get it in for transmission service next week. I would appreciate any suggestions.

lesgorv · 04-16-2007, 08:00 AM

GaDawgFan
There have been lots of posts about mountain driving. Such as how fast, what gear, peak RPM. I hope you have as much fun learning as I did. On my last trip form Virginia to the Rockies we traveled from Yellowstone south to Darango CO and home with an average of 9.6 mpg pulling a Jeep. I was not disappointed at all with the performance of my 300 Cat.

2000 Horizon 36LD
Jeep Wrangler

GaDawgFan · 04-16-2007, 09:19 AM

lesgorv,
Thanks for the response. Since we are talking about the exact same coach here, did you find yourself having to manually downshift the transmission or do you let the transmission simply do its thing. My experience may be that the transmission is doing exacty what it is suppose to do but I need to be something.

LK23 · 04-16-2007, 12:06 PM

Watch your engine tempertature. When you see it start to climb, downshift.

I travel in the mountains frequently. The only time I have had to downshift was in May in Utah. I have a 400 ISL in a Horizon 40AD.

Pusherman · 04-16-2007, 01:07 PM

The allison control pads with only one window show the gear selected. Therefore if you put it in Drive, 6 will show in the window, and will not change unless you downshift manually. The new coaches have 2-digit windows, showing the gear selected, and the actual gear the transmission is in.

Generally I would recommend letting the transmission shift itself, even when driving in the mountains. The exception is if your engine temperature begins to climb too far. The engine gets optimum cooling at 2000 RPM, so manually downshifting to try to maintain this RPM level is advisable when the engine begins to heat up.

The other thing to consider for your transmission service is to change to TranSynd synthetic oil for the tranny. It is far superior in heat dissipation, and allows for longer service intervals. If you do not have TranSynd in the unit today, then it will take 2 oil changes before you can follow the longer service intervals with the synthetic oil.

Go to Allison's website for more info.

Ron-in-Tn · 04-16-2007, 04:50 PM

There are many features of the key pad on the Allison to include checking the fluid level (right from the comfort of your driver's seat), displaying fault codes, changing to the "Economy" mode and so on. I would highly recommend reading through the owners manual as there is plenty to learn on this. When traveling through the Black Hills in South Dakota, I found that if I left the cruise control on, the performance seemed to be much better than if I kicked it off and manually throttled through the hills...just an FYI.

David K · 04-17-2007, 03:38 PM

Gadawgfan

I bought my 2002 and it did not have good maintenance information on it either. One of the first things that I did was to take it to Cummins South and let them change the tranny and engine fluids and filters. It is a little bit of sticker shock (my bill was $585.00 for the job) but, I felt better about it afterward. They let me look under the coach while they had it up and showed me all of the lub points, other filters and they also did a general check over of the chassis also. Bill is the super down there and he has worked with me on other items that have come up. You do need to call ahead of time and make an appointment but, normally not that bad to get in. They are the authorized service center for both the cummins engine and the chassis.

You can go to Allison't web site and get an electronic copy of the manual covering your tranny if you do not have the hard copy in your black book. It has a lot of information about what the display can show you. I have not made the change to the synthetic oil due to the cost and I plan on having the oil changed on at least an annual basis regardless of the mileage.

rvarner · 04-17-2007, 05:33 PM

David
That's cheap. I paid $256 for oil, filter and fuel filter plus another $500 for trans drain and fill (not transynd). I know, "theres one born every minute" Findlay in Las Vegas.
Richard

David K · 04-18-2007, 05:03 PM

Richard

I was just trying to prepare him for the cost of the service. I think that Cummins South does a good job and I have found they do not overcharge for what they do. Also good to work with you on the extended service warranties -- I have one and Bill has always taken care of the front end work with the warranty people. Last time we used it was to replace the hydralic fan hub -- Bill got all but $128 paid for by the warranty people -- total bill was over $1,200. I have been very happy with them and recommend them highly.

Carnles · 05-03-2007, 07:16 PM

GaDawgFan--
I'm very new to diesel coaches also, but on my coach, which is also equipped with the 6-speed Allison transmission, the "6" number you see is the highest gear that the transmission will be allowed to shift to. By pushing the drive button you are allowing the transmission to use all of the available gears. When you shift up or down you manually limit the transmission to the gear you select so the number displayed will be the highest gear that can be used.

A question for you...does your coach have an engine brake? If so, you should turn that on when doing hilly driving (especially when going down hill) to prevent service brake heating and premature failure.

On a side note, you should go on a trip to Cloudland Canyon State Park. Unicoi is nice with Helen and tubing and stuff, but my wife and I enjoy Cloudland Canyon much more.

If anyone sees any misinformation please let me know...all I know is what is in the book and what I have had practice at so far.

vicsryd · 05-04-2007, 05:21 AM

I generally have the exhaust brake always enabled on-highway. It adds a another level to general braking. I think anything to help improve the stoppoing distance of my 14+ tons w/ toad going 60mph, espeically if you encounter an unexpected situation, is desireable. I also find it just right for dealing with merging traffic.

In my rig at least there is a sweet spot when you just barely depress the accelerator where it is coasting without the exhaust brake. As such I have full control over when to use it or not without having to turn the switch on or off.

Glock Guru · 05-05-2007, 04:51 AM

The Allison web site has lots of good information in PDF and on Real Player video. The videos and print go into great detail on how the products work and why. Check out the site and most of your questions will be answered.

-Troy

John_Canfield · 05-05-2007, 05:17 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Carnles:
GaDawgFan--
I'm very new to diesel coaches also, but on my coach, which is also equipped with the 6-speed Allison transmission, the "6" number you see is the highest gear that the transmission will be allowed to shift to. By pushing the drive button you are allowing the transmission to use all of the available gears. When you shift up or down you manually limit the transmission to the gear you select so the number displayed will be the highest gear that can be used.--snip--
If anyone sees any misinformation please let me know...all I know is what is in the book and what I have had practice at so far.

</div></BLOCKQUOTE>You're right on track with the Allison display info. My coach (with the Jake) will display a "2" when the Jake is engaged, or a "6" if we are in "Drive."

The Allison electronics are smart enough to not let you do something stupid like actually going into Reverse while rolling forward, or shifting into Drive with the engine idling too fast.

Our coach came with an informative VHS tape describing the Allison operation in a bit of detail - if you don't have a copy, I'll bet Allison will be glad to provide one.

Pusherman · 05-05-2007, 03:20 PM

I had my engine brake reprogrammed to select '4' instead of '2' when the engine brake is engaged. I find it much more driveable with this selection.

I use my engine brake moreso to slow the coach on highway conditions such as when exiting onto an exit ramp, or slowing down a hill.

Even though the Allison will not let the transmission downshift to a lower gear until your speed is correct, I found it too severe to downshift to 2nd.

I had Allison reprogram this feature (they didn't charge me).

Jestme13 · 05-14-2007, 04:04 PM

Don, is there any chance of the engine brakes being set up as 2 stage ???

Pusherman · 05-14-2007, 04:28 PM

Hey Steve -- where've ya been! Missed ya!

Unfortunately there's only one selection to make for the engine brake programming -- you can pick any gear for the engine brake to select to downshift to (not sure about 1st), including 6th gear.

What I do is if I want more braking power I will manually downshift below 4th if called for due to conditions. So after the engine brake chooses 4th, I can then manually downshift to 3rd or below if I so choose.