S-10 drive shaft vibration

[StevanSimmons]

I have a 95 S-10 Xcab 2WD with a 4.3 V6. The truck is new to me and has nearly new tires. At hiway speeds between 30 and 40 mph a bad vibration starts up and peaks about 35 mph. I have swaped both rear tires with the front with no affect. Braking makes no difference. Takeng the engine out of gear makes no difference. I've noticed there are 4 UV joints with three drive shafts in this truck. I can't feel a lot of play in the differential gears or in the wheel bearings. Anyopne seen this problem before? I sure could use a pointer on repair or troubleshooting here.:sun:

[vickk12785]

Your problem is one or both cardan joints(heavy duty u-joints). I had a guy rebuild mine. He charged me about $200 which was cheap. I assume you have already inspected the driveshaft and it seems as though everything is nice and tight right? That's the wierd part of it. I could not tell that they were bad by moving them back and forth like a regular u-joint but a master mechanic friend of mine assured me they were bad and he was right. If you go to a dealer they will try to get you for the whole drive shaft ($800-$1,000 just for the part). These cardan joints are super heavy duty but they can be rebuilt. If you are in the NY area the guy is Don at Drive Shaft Inc./(845)733-4655/Bloomingburg,NY the guy is a pro and he was done in 2 days. I removed and re-installed the shaft in 10 minutes myself. I realize your post is over a year old but I replied so someone else with the same problem may benefit from it. I ran mine with the vibration for several months till I finally got it diagnosed. Good luck brother gearheads.