Questions and Answers

GMC Caballero Just Clunking Around Q. Mr. Ciulla, I have a 1978 GMC Caballero that has been neglected for years. The clunking noise has been going on for several years along with noise/vibration at 55 mph. About six months ago I took the car in for U joints, front and rear, to be replaced thinking this was the problem. The mechanic said they didn't look bad but replaced them as I wanted. Noise was still there.

May 20, 2004 I had the car in for a transmission check since it has never been serviced. The mechanic gave the car a good once over and found several problems requiring immediate attention.

Left front wheel bearings were shot and he said the tire could have come off. Transmission fluid was changed but otherwise was in fairly good condition. He replaced wheel bearings on left wheel and repacked right wheel. New tire rods were mounted, new shocks put on and he replaced a cracked motor mount. Front end was aligned.

I initially told him the that the U joints were new and I was concerned about the clunking sound from Park to Drive. Apparently he couldn't find the cause because it still exists. Is there any chance that the U joints being replaced before all this work was a mistake? Should I have the U joints replaced again?

What else should I consider regarding this clunking sound? The engine was given a tune up also, including a carburetor overhaul.

Thanks,
Bob
Salinas, CA

A. If this noise can be duplicated fairly easy, I can't see why someone can't find where it's coming from. You need to see someone else who wants to fix the car, not just hang parts. If someone tells you the U-joints are bad, make sure they will stand behind their work if the noise is still there when you pick it up. Demand your money back if necessary.

Has anyone checked the rear differential for excess play? I have seen them where you can turn the driveshaft a half turn before the wheels start to turn. This will make a big clunk.