Allison MH 3000 Shift Problem

Gerel Thompson

New Member
I have an 2002 Tradewinds with Cat 330 and Allison 6 speed tranny. This summer I experienced the tranny "dragging" when it shifted from 2nd to 3rd and from 3rd to otherwise, instead of a clean, crisp was a slow, soft shift that caused rpms to go up before it shifted. Allison in Indiana serviced the tranny, downloaded new software to the ECU and no difference....they then put it in normal adapt mode and drove it for about 4 hrs when it finally began to shift normally again.

So, we head out to Florida and on the way down it begins to shift poorly again...just like it did before having it looked after in Indiana. I decided to put it into "economy mode" and immediately the shifting was like normal...but after about 450 miles or so, it began to shift poorly in that mode it doesn't shift the way it should in either mode.....

Anyone experienced this....resolution, etc. is greatly appreciated.


IU Fan
Tradewinds LE 2000
30,000 miles
Towing a Saturn Vue