the dealer installed a new diff. Now I can feel a vibration when in motion. It's noticeable from 0-75. above that speed it's drown out by the road or it's too high a frequency to differentiate from the normal vib. The vib is subtle but enough that it causes a tingling sensation.

I'm going to take it back to dealer, but they'll probably try to bs me. Unfortunately I don't much clue myself. Anyone have any ideas?

please help! Thanks!

 

no clue, but take the service manager for a ride and let him feel it, dont take no for an answer

 

Maybe they put improper fluid in it? Or there is a bolt loose on the rear mount? Youd have to get under it

 

let us know what you find out. thanks.

 

Under acceleration or deceleration ?

 

I would try unbolting the driveshaft and rotating it a hole. The shafts are balanced and matched with the pinion flange. I replaced my diff a long time ago and it vibrated and rotating the driveshaft fixed it.

 

hmmm good idea, I am having a similar issue, did not think to index the holes when disconnecting my prop shaft...now it vibrates a little bit, doesnt seem like the orientation should matter however since it is cylindrical

 

alright, I had the wheels rebalanced somewhere else. When the mech put the car in the air, he did a suspension visual check. He found that the CV shafts are sloppy on the diff end. The end attached to the hub/wheels is tight, like the drive shaft. But the diff end can move up and down (radially).

Is this normal???

 

also, I assumed the dealer got the entire assembly, and all they did was bolt things up to it. When you replace the diff, are there any special procedures that goes with it? like shimming...etc? Or is it just a bolt on and go?

and according to the dealer paperwork, they put 8090 gear oil in there.

Thanks much!

 

Maybe the pinion nut was loose? It could very well be the condition of the inner CV joints. Also check air pressure in all your tires. I wouldn't be worried about the orientation of the driveshaft as they put in a new diff with a new flange. If you have a diff rebuilt it would be a good idea to mark it and put it back together the same way.