Service people could not duplicate the problem. Now with 62000 miles the torque converter needs to be replaced & warranty has expired so it is costing me $1117.75 to replace it. Because of the clunking noise, I have opted to replace the whole transmission at a cost of $2633.44 to ensure no other problems will show up that will cost me more. The replacement transmission comes with a 3 year 100,000 mile warranty. I thought because of the clunking problem GM would at least cover the $1117.75 because the problem was brought to their attention way before the warranty expired even though the problem is just now being fixed.

Tranny started clunking a few months back, once every now and again.Didn't think much about it until the tranny's gears started winning. Also it gets louder as you decelerate and feels and sounds as though it is not lubricating very well. 47,000 mi. now so have not been in to service the tranny; book calls for 50,000 mi. Called a set an appointment for Aug.28, 2008. I have a extended warranty so we'll see if the Dealer replaces the tranny or tries to squirm out of it. I will check back after seeing the dealer.

I have a 05 Silverado 2WD reg cab with a 4.8 that has a similar problem like yours. When I accelerate in 2nd, I get a clunk from the tranny. I had it to the dealer & they replaced the Prop Shaft which didn't help. They checked the rear end & told me everything was fine. The dealer told me that the truck is operating under normal conditions and this is normal for a long box 2wd Silverado. I'm still at wits end with the noise. I even involved the GM AVM., which was a waste of time. Any new input anyone has would be appreciated. Thanks.