Clunking Noise =(

**blueZ71** · 02-02-2009, 11:10 PM

Hey there. Maybe I'm just not used to all the clunking and rattling of a truck but I'm sure this one should not be happening. In my 2000 silverado I hear a loud very audible clunking noise (passengers notice it as well) which sounds like it's coming from the rear of the truck whenever I accelerate hard from a dead stop. It sounds like something in the drivetrain is slipping and then catches suddenly. I posses nominal mechanical knowledge but I'm thinking maybe the u-joints need to be replaced? Anyone else every experience anything similar or willing to shed some light on the situation? Thanks a bunch!

**retired2001** · 02-03-2009, 01:09 AM

Is it a "single" clunk just on taking off? If so it may well be slack in the drive line. There have been "clunks" coming from the shaft coming from the splines in the transmissioin. Also, might look at all suspension bolts. At least a place to start looking. Good luck!

**vncj96** · 02-03-2009, 02:15 AM

Most likely u-joints or rear end, crawl underneath and try and twist the driveshaft, I bet you have alot of play in it

**blueZ71** · 02-03-2009, 03:08 AM

Yea it's a single clunk. What would cause play in the driveshaft?

**vncj96** · 02-03-2009, 03:25 AM

The u joints are shot or if your rear end has some problems it will start to allow slack, the rear end thing can be a bunch of different things, but if there is too much play while its in park then its one of the two. So just try and turn it and see how much you get

**mrfixdit** · 02-03-2009, 04:17 AM

Do you have a posi rear?

**blueZ71** · 02-03-2009, 09:12 AM

Originally Posted by mrfixdit

Do you have a posi rear?

Not sure. It's the z71 so I would think so.

I'll check it tonight after school and report back.

**cascott325** · 02-03-2009, 04:30 PM

i have the exact same thing in my truck. one single clunk and its over till i stop again and then take off... just on the take off, not on the stop. i have replaced the rear end with a used one, and the u joints, so im sure its neither of those. i had the same thing with the old rear end and u joints, so i dont know. wasnt sure how to explain it, so i didnt post about it, but you did a good enough job for the both of us. i dont know what it could be.

**bartmk** · 02-03-2009, 06:50 PM

I've done all kinds of research on this subject myself. I have a '01 Silverado Z71 with the same thing going on. From the other forums I've read it's the piece that slips into the transmission and connects the trans with the driveshaft. My driveshaft has no play in it but I get the clunk also. Supposedly it's that piece (the tube shaped one with the spline on the inside) that needs to be replaced. From what I've read GM offers a replacement one that is of better quality. The guys on the other forums seem to get the same message from the dealer... they tell them that it's a normal noise. Not sure I believe that but I'm just going to let mine be for now.

**cascott325** · 02-04-2009, 10:10 AM

Originally Posted by bartmk

I've done all kinds of research on this subject myself. I have a '01 Silverado Z71 with the same thing going on. From the other forums I've read it's the piece that slips into the transmission and connects the trans with the driveshaft. My driveshaft has no play in it but I get the clunk also. Supposedly it's that piece (the tube shaped one with the spline on the inside) that needs to be replaced. From what I've read GM offers a replacement one that is of better quality. The guys on the other forums seem to get the same message from the dealer... they tell them that it's a normal noise. Not sure I believe that but I'm just going to let mine be for now.

i seem to have a normal driving and performing vehicle, so except for the noise, i think every thing i ok and wont take it any where as well