There's a transmission "bump" on my 08 Tahoe. It happens most of the time when I stop for a light or an intersection. It feels like someone has bumpedyoufrom behind. Additionally, if I am coasting down for a traffic light and then apply gas lightly when light turns green, I will sometimes hear a distinct clank noise and feel a shutter through the truck.
It's been one year already since I bought my Tahoe. I had this problem once in a while before but lately it's been ocurring every single day.
I read some post about this issues and I was wondering if anyonehad this problem resolved.
Dave mentioned that the GM engineeringwas working on an updated piece of software that will eliminate this problem. Does anyone knows if this update is already available?

I wanted to check on this forum for any updates before I take it back to the dealer.

Thanks for any info.

Happy Thanksgiving to all on this forum!

 

My 97 Tahoe did this and when I took it in they said they lubricated the tail piece of the drive shaft, it stopped it for about 6 months but it returned.
I noticed that it would happen more often when I stopped not hard but quickly and as long as I kept my foot on the brake it wouldn’t do it until I released the brake pedal.
Like it was keeping something loaded or in a bind.

 

This is the same problem I had with my 07 Silverado LTZ (the LTZ is set up just like the Tahoe). Read this thread https://chevroletforum.com/m_79524/tm.htmand as it says, tell your dealer there is a bulletin on it. The last time he re-greased the driveshaft slip yoke and the new lubricant partnumber is #12371287. He said the new grease should fix the problem for a long time.

 

I took the Tahoe to the dealer today and mentioned to the service writer the information you provided me.

It took them about two hrs to fix the problem. This is what they wrote on thereport "Removed drive line & cleaned splines inside yoke. Applied lube to splines & reinstall drive line.

I drove back home and WHAT A DIFFERENCE!! The ride is very smooth now. Couldn't be happier!!!

Thank you very much for your help.

 

Butarn't the splines on the yoke bathed in transmission fluid?
Guess that iswhat there doing is putting on a heavy viscosity lube that performs better as a lubricant then hydraulic fluid....

 

JC10 you're most welcome. I guess that's what these forums are for! I not only noticed a difference in the "bump", but my overall ride was smoother. It's been over a month since they applied the "new improved" grease to my truck and it's still doing great. They said they shouldn't have to do it again, but as long as it's in warranty, I'll be taking it back if the problem returns!