Allison Transmission "Slipping" when below 30 degr

[polecat]

Hello Allison Man...I was just referred to you..maybe you can help...our 2002 Allison equiped DP will "slip" or "hunt" between gears when the temp is below 30 degrees...it takes about 20 miles or so before it starts to do this, and does not clear up or get better..we have been lucky that we have been close to home when this occurs as it hard to keep the coach moving...usually in the 40 mph range with pushing it hard..just basically letting it hunt around while keeping this speed...had it to Kansas City area Allison facility the first year it did this...they could not find anything wrong using only their little hand held computer..they did not drive it...they said it probably was a Freightline problem with their wiring harness...I really don't think they believed us entirely..as they kept saying they had never had one do this before...can you give me some ideas to talk to them about when I take it back in this month (warranty is getting close to running out)...thanks, Larry