I have a 2004 3500 quad cab long bed srw 4x4 duramax allison, whew! I replaced the u-joints and the carrier bearing but now I have a vibration at 40-45 mph in the truck. I talked to a mechanic and he said the that the weight of the drive shaft is too heavy and that is why they (Chevy) switched to an aluminum drive shaft. Anywho, I've been looking online for a an upgraded driveshaft and I've found some specialty companies but no real luck on replacing the one on my truck without doing a custom job. Does anybody know of a company that replaces stock drivelines?

 

are you sure you reassembled exactly the way it was because they are balanced a certain way and you may have one of the shafts 180 out

 

Are you saying one of the yokes is 180 out? I have a 1500 4wd Silverado with the same symptoms. Vibration around 40mph. Reappears at highway speeds but not as much.

I have replace the Ujoints twice but did not pay attention to yoke orientation. Do you think they are marked in some way so you can see how they are supposed to go? It would be a pain in the butt to swap one and then the other to find the problem. Any other ways to diagnose this issue. I just put 4 new tires on the truck and both front wheel bearings are pretty new.

Thanks

Dave Cover

 

when you take them off you are suppose to mark them just try spinning it 180 and try that before dumping money into it