rear end clunk

[clinebarger]

Originally Posted by Boog

I have what can be described as a "clunk" in the 06 GMC. Happens only on the 1-2 shift. Feels like it's from the rear end. There is no gear whine or howl however. The truck has the 5.3, auto w/od, 4.10 gear with gov lock with 110,000 miles on it. I haven't looked at the ujoints yet. Any ideas?

Remove the driveshaft & lube the internal splines on the slip yoke....Retest.
Get back to me on what you find.

Inspect the U-loints while the driveshaft is out.