Jump from full stop or going into drive.

[LeRoy]

I just recently purchased my new (to me) 2005 Silverado 2500.

When I shift from Park into Drive, the truck seems to Lurch or Jump forward pretty hard. It also does this when at a full stop and letting my foot off the brake before touching accelerator. When I come to a full stop, it seems to stop, then fall back just a bit.

Other than that, it runs and shifts very smoothly. Tow / Haul works great, and OD on / off works perfectly. There are no error or check engine lights on.

I'm not extremely mechanically inclined, but it seems like something isn't right with the transmission. I called the Dealership today and they told me that driving a truck with an Allison transmission is feels different than every other truck. This is the first Duramax / Allison truck I've driven. I have driven the Ford & Dodge diesels. This doesn't seem normal / right to me.

I think I'm going to take it in next week, but before I do, I thought I'd ask here.

 

[duramaxdiesel]

Yeah I was gonna say what the Allison dealership told you. The Allison does have different characteristics than say a 4L80E. It's a commercial transmission. I think what you are experiencing is normal. But still take it in anyway and see what they tell you.

Nick

 

[duramax05blk]

Sounds like Fprv does engine surge if in drive with foot on brake in traffic or stop light

 

[LeRoy]

I spoke with a few dealers looking to see what everyone's diagnostic fee were and how they handle them. While talking with them I mentioned this problem. One suggested that he thought it sounded like the slip yoke needed to be lubricated. He said that is a fairly common problem.

I'm taking it in to the dealer to have it looked at tomorrow.

 

[MACKIN]

If your feeling what feels like suspension recoil ,you come to a stop and the rear feels like it squats, or feels like someone bumped into you , then it probably is the slip yoke.

I don't understand the forward lurching? Does the tach move? When ever I've felt that the torque converter is dragging.

 

[LeRoy]

The truck was in the shop on Friday. They found it needed a new bearing and drive shaft center support. While they were there they lubed the slip yoke. When I picked up the truck it was running perfectly! Right around $500 to resolve and covered by extended warranty 100%.