im prett new to the diesel and allison tranny... sometimes when i go over a bump or even had it happen on making a turn, the tranny acts like it misses a gear. i press the gas and i just rev up the motor... let off the pedal and then press it again and it catches.. is this normal or should i have it looked at?

also when i slow down sometimes is it normal for this tranny to downshift a lot? i mean i slow down make a turn and just kinda coast for about 500 feet at about 20mph and the tranny downshifts hard at least 3 gears... im figuring that it isnt dwnshifting when the brake is pressed and im slowing down???

hope this makes sense...thanks guys

not sure about the first part but I am the second part. Yes the tranny is downshifting. It aids in keeping the brakes lasting longer and with towing heavy loads. Normal operation. I got use to it pretty fast and find myself not braking as hard as I use to in my 1500hd.

Does the missed gear happen every time you hit a bump or turn a corner? If it does take it in and have the dealer look at it. If it is an intermittent problem the dealer may have a hard time diagnosing it.

Sounds to me like it is low on fluid. It is common for it to slip on a turn because the fluid goes to the outside of the turn and the filter picks up air.

the slippage doesnt happen all the time.. the truck is not even a yr old...

Have you checked the fluid level?

Have you checked the fluid level?
yeah they have... look good.