'01 Sierra Z71

[tkidu]

First off, let it be known that I am fairly new to the truck world, as I am only 18, and I don't know an awful lot about trucks...

 

My dad decided to give his 2001 GMC Sierra with 172k (mostly highway) miles on it and is now gonna buy a new '07 but back to the question.. I used to drive it around a lot around 140-150k miles and it never seemed to have this problem..

 

Whenever I put it in reverse, the transmission or something in the back of the pickup makes a big clunking noise, sometimes it's big, sometimes it's not very noticable at all. I had the guys at my local chevy dealer take a look at it, and they said that it was the U-joint, but that didn't seem to be the problem.

 

So I guess what I'm asking is, why does it do that? Will I be able to drive it for very much longer? please help me out

 

edit: I also forgot to mention that when shifting from 1st to 2nd gear, seems like it hesitates before shifting, then makes a clunking noise when it does, any quick fix for that?

[asilverblazer]

If it is the U-joint it won't last long. Try moving the driveshaft by hand if it moves that is a bad sign.