[richk]

Well my dealer may have finally found the source of my vibration and knocking problems:

My H3 was making the knocking noise real bad yesterday so I stopped by the dealer and was able to get it knocking by moving forward only about 1 foot and hitting the brake. The service tech and I drove around to the service bay and I had 4 mechanics around the H3 all listening at the same time. They could actually hear the noise by having me put it in park and pushing front to back. They could actually "feel" the knocking in the rear tires. They immediately said it was a bad differential.

They showed me a bulletin dated yesterday from Hummer that says rear-end replacements are now on hold until they can figure out why so many are failing. They are telling me I will have to wait until GM figures out a solution.

In case any of you read my others threads regarding a knocking noise that is only heard when the truck warms up. Or you may have read my complaints about excessive vibrations coming thru the gas pedal. The dealer has diagnosed both of these issues as the rear-end differential. Now I am just playing the waiting game until Hummer comes out with a solution. I plan on bugging them about every 2 weeks until its repaired. In the meantime I am driving around with a bad rear diff.

I feel like a weight has been lifted because at least now the dealer acknowledges my problems. And even if their diagnosis is wrong, they all have heard the knocking noise very clearly.