Allison Shifting Problems

mschaffer66 · May 31, 2006

I have an 03 Dmax with around 90k miles on it.

I have recently noticed that when leaving a light if i "get on it" my trans won't upshift correctly. It will get to about 40-45mph and just stall there for a second or two, then shift. Its a long enough delay to really scare the crap out of you if you are pulling out in front of someone.

I've also had the same problem while at cruising speed of 50 or so and going to pass. It will downshift, then as it comes up towards 60-65 it won't upshift to the next gear.

Has anyone else had this problem? Is it worth taking in to the dealer? I still have an extended warranty so the worst its going to do is cost me $100. Does anyone have any hard info on what could be wrong?

Thanks

snoman · May 31, 2006

I have an 03 Dmax with around 90k miles on it.

I have recently noticed that when leaving a light if i "get on it" my trans won't upshift correctly. It will get to about 40-45mph and just stall there for a second or two, then shift. Its a long enough delay to really scare the crap out of you if you are pulling out in front of someone.

I've also had the same problem while at cruising speed of 50 or so and going to pass. It will downshift, then as it comes up towards 60-65 it won't upshift to the next gear.

Has anyone else had this problem? Is it worth taking in to the dealer? I still have an extended warranty so the worst its going to do is cost me $100. Does anyone have any hard info on what could be wrong?

Thanks

<{POST_SNAPBACK}>

Have you done regular servicing of tranny (oil and filter changes) ? Also if you take it in and you have oversized tires, loose them before you do as GM can void warranty if tires are bigger than 265 in size.

dewfpo · May 31, 2006

First things first...have you checked your fluid level? and like snoman says...... have you changed your external spin-on?

DEWFPO

Jake99Z71 · May 31, 2006

Make sure to change your spin-on every 10k miles at the most. Where are you located? Someone with a Tech II or EFI Live could reset your taps and look at them to see if this could help you out.