2007 Gmc Thunk!

[OpiemusRex]

Hello, I have a 2000 GMC Sierra 1500 z71 with less than 56,000 miles. Truck is totally stock and in great shape. The only concern that I have is that when taking off from a stop I get a distinct "thunk" coming from the rear of the vehicle. I thought that it might be a bad U-joint but they all feel good. It almost acts like there is some kind of slop in the rear end.

 

This has happened ever since I have owned the vehicle which was in 2004 when my dad died. He bought it brand new.

 

Any thoughts?

 

Thanks

[ColoradoSkiCountry]

I'm going to bet it is the Slip Yoke. Very common problem on the 99-03s, solution is usually replacing the slip yoke with a newer nickel plated yoke (which they started installing in 03) and that takes care of the issue. My 99 had this same problem as did many others back in the days on this forum who owned the 99-03s

[MarkD]

My 03 has it, and I had to explain the fix to the dealer. Then they turned me down for mileage.

 

Apparently if you can get away with something for long enough, you are no longer responsible.

[Spurshot]

Pull the driveshaft and grease the splines with a good synthetic grease. Chances are good that it'll cure the clunk for a good long while.

[Airspeed-Alive]

Our 03 does the same thing. I'll have to try adding some more grease to it.

[stadt11]

I'm going to bet it is the Slip Yoke. Very common problem on the 99-03s, solution is usually replacing the slip yoke with a newer nickel plated yoke (which they started installing in 03) and that takes care of the issue. My 99 had this same problem as did many others back in the days on this forum who owned the 99-03s

http://www.gm-trucks.com/forums/index.php?act=Search

 

or

 

http://www.gm-trucks.com/forums/index.php?...p;highlite=yoke

 

or

 

http://www.gm-trucks.com/forums/index.php?showtopic=84509

 

or

 

http://www.gm-trucks.com/forums/index.php?showtopic=86083

 

(search is your friend )

 

BTW, Welcome To The Greatest Site Ever!!!!

[sams819]

Hi, your dealer has a sheet on this problem. They first replace the front yoke with a nickle plated one as stated in an above repley. Then the will give you a sheet from gm saying it is a normal condition that is caused by the transmission. something to due with the trans dics reversing between 2nd and third gear. ???? I had this problem in my 2004 and 2006 silverado. My 2008 seems better.

[Zembonez]

It's the slip yoke.

 

I fixed my 01 in about ten minutes. Good marine grade wheel bearing grease inside the splines and the problem went away for several years until I sold the truck.