I am getting vibration from 25 mph to 55 mph in the drive train. When shifting to a lower gear going down a steep road I get a clunk. Sounds like U joints but they don't look loose. When I turn the drive shaft that is in front of the transfer case I hear a noise in the transfer case. Can U joints be bad but still appear tight? Can a transfer case be rebuilt like other components?
I have a 1994 S10 Blazer. It is a four wheel drive with the push button selector. Last hunting season I noticed that when I was in 4 wheel drive and I shifted down to keep my speed down on the mountain roads I was getting a clunk. Now, it is vibrating from 25 to 55 mph when I am just in drive. The vibration stops when I go faster, or when I take it out of gear. It is definitely in the drive train. I thought it was a U-joint, but when I check them all 4 seemed tight to me. I turned the front drive shaft by hand and noticed some noise in the transfer case. Is there a kit to rebuild this component? Can the U-joints look godd but still be bad?