I just recently had a shop put in 4.10 gears in my rear dif and 1st thing I noticed on the ride home was a "Noticeable" vibration on the freeway on ride home. Revs were about 3000 at 70-75. It vibrates moreso when I let off the gas. It has progressively gotten worse and now will not drive it until I fix it...but first I need to figure out what it MAY be. Is this a suggesting my bearings weren't replaced or if they were replaced maybe installed crooked? I have an aluminum driveshaft, maybe the U-Joint needs replacing? Oh, and now im leakin out of the diff...I haven't pinpointed where yet, but will try and find out this weekend. Anybody experience bad vibrations at higher speeds when letting off the gas? Thanks for your help.

 

Try removing your driveshaft, turning it 180 degrees and then reinstall it. Check to make sure that the shaft and u-joints are in good shape. If that doesn't fix it, take the car back to the shop where the work was done.

 

Thanks, I'll start off there. Im sure replacing bearings (if thats the problem)could be a pain in the tail...i was just trying to get away from that option because the shop is about 70 miles away, but they only charged 700 cash for the 4.10 set, posi and installation. Other quotes were runnin at over a grand.

 

Could that be the problem?

JamesC

 

It could be other things, but vibration or noise when letting off the gas could be a problem with the coast side of one of the gear teeth. I'd take it back.