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trying to get in touch with alisonman to ask this question

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Doc3254:
I recently purchased a repo motor home....it's a 2001 Harney with a cat 330hp and an alison 6 speed automatic.  I got a real good deal on it and as always with thing you buy over the internet it had some minor issues, I mean really minor stuff like missing screws and trim washers that vibrated loose and fell out, nothing major.  The only issue I am questioning is the way the trans shifts, I have a "Class A" CDL and drive the big boys but never drove an automatic and just feel this isn't shifting as it should and is wasting the HP under the hood and fuel as well by laboring in a higher gear when I would have already downshifted a manual trans to keep my RPM's up and the engine working in the power band.  I didn't get to test drive the unit before I bought it at auction but the dealer said it drove and ran fine.  It does run well, as I said but it is a dog on hills and I have to keep and eye on the RPM's and manually down shift the push button selector to keep the road speed up for the type of grade it is pulling, I kinda missed the Q's on I-77 N and lost it on the big hill and cause the R's to drop below 2000 and in an empty coach only pulling my Mini Van on a tow dolly the 330 HP should have pushed 65 up that like nothing but the trans didn't down shift even with my foot to the floor board.  I got home fine except for that incident and did the minor repairs and some things to customize it to my liking as I use this for work as my home away from home (sorry I just hate motels) for extended periods of time like I usually go for.  I located the Alison Manual on line and read it cover to cover and it explains about the push button "E" for economy mode but also mentions different S2-S7 modes where the Manufacturer can set the shift patterns for more aggressive driving and towing which would use the Cat engine's HP to my advantage.  Is there and aftermarket programmer that I can buy to change the shift points/power band RPM's to get this to perform the way I like to drive (like I stole it) or do you have any other suggestions.  Thanks Doc,  illeagleinpa@yahoo.com

Tom:
Hi Doc,. Unfortunately, allisonman hasn't neen around for quite a while, and efforts to contact him have failed. Maybe one of our forum members can answer your question.

Gary RV Roamer:
I think your expectations are too high. The Allison 3000MH is tuned for best fuel economy rather than max acceleration and performance. And the rear axle ratio is not designed for charging up hills either.

By the way, the sweet spot on my Cummins ISL 370 is at about 1650 RPMs. Max torque is in the 1300-1600 range and horsepower peaks at 1800. I would not want to pull 2000 RPMs. Guess maybe I have a different driving style? But I agree the performance on grades leaves something to be desired!

As for aftermarket tuners for the Allison ECU, I'm not aware of any. You might be able to get an Allison shop to install a different profile, though. They have different shift patterns for different applications.

BernieD:
As Gary said +1

My first DP had a CAT 275hp and Allison tranny. Once I learned it's quirks I had no problems in the mountains (Rockies, not Alleghenies). As I approached the climb, I increased my speed about 5mph, took the mode button out of economy and downshifted to 5th manually. I know I go against the grain on this forum, but I found climbing with my cruise control on worked for me. I wasn't the first up the hill but there wasn't anyone there handing out checker flags and I still passed most of the trucks. The engine ran cooler and I got better fuel economy.

My current coach weighs about 5k more but and has 400hp and 1200#/ft torque so I just leave it in cruise control, sometimes after switching off economy mode, I don't worry about slowing down on the steep ones and I still pass most of the trucks.

Doc3254:
thank you all for your input, I will have to learn to adapt to the querks of the trans......I may have to use 5 th gear more frequently and maybe even 4th for hill and dale type of road conditions.  I must have under estimated the shifting cycles of the Alison and thought it would kick down by itself on foot to the floor command to downshift in the 5 &6 gear (overdrives).  I only drove the unit 3 days so far and 2 them were when I drove it back from SC when I picked it up and the last time was when I drove it about 135 miles to set up for a job lasting three months.  I will try  all of your suggestions and appreciate your input and advice.  Doc

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