Drive Train Axles Bearings problem
1967 Pontiac GTO V8 Two Wheel Drive Automatic 122000 miles
For over 2 years I have had an undercar noise that generally occurs within the first few miles at low speeds. The noise is described as "something binding up then a clunk or pop followed by a squeel or hiss. This usually lasts just a very short time (30 seconds) and then goes away." Two years ago, a mechanic repacked my front wheel bearings and replaced my water pump. Problem still existed. A year ago, I replaced my front shocks. No cure. Six months ago it dawned on me that maybe it's my u joints since they had not been replaced in over 30 years. I replaced the U joints with greaseable joints and the problem seemed to go away for 6 months until yesterday. Then I heard the symptoms twice after an hour long drive. Any suggestions on what component might be causing my problem? Incidentally, I bought this GTO new 43 years ago!
If this car has a positraction rear end, change the rear end dope. Also go to a dealer and they have an additive that helps these units. As this in's driven long or often probably your posi unit may be sticking. The hiss may be an exaust leak, but it would depend on which side. It could be something in the transmission but you didn't state whether it's a stick or automatic.