So i took my car to this mechanic and he fixed my pinion seal on the differential but now its making this whining and grinding noise i have never heard before... im not that great with cars so could anyone tell me what the possibilities could be?

 

Does the noise trace acceleration? I would try removing the belt and running the engine to see if the noise disappears or not.

 

yup took it to a shop today and they said i need new gears and bearings Is 650 good for a rebuild?

 

The pinion bearing preload was not set correctly after replacing the pinion seal. Take it back to that mechanic, light him up, and demand that he sublets the vehicle for repairs, OR pays the bill for another shop (of your choice) to repair it. DON'T LET HIM FIX IT! He's obviously an idiot who couldn't do the job properly the first time.

ALL GM 7.5" 10 bolt rears that come in with pinion seal leaks I sell a crush sleeve replacement as well. Other manufacturers axles are more forgiving, but our rears are REALLY picky.

 

QFT.

 

Yeah i will definitely do that thanks... a good friend of mine was suggesting getting gears... maybe 3.73s or 3.42s im not sure if thats the right way to go for a car thats completely stock though

 

If you have 2.73 gears now and plan to remain completely stock, 3.42 would work very well.

If you have 3.23 gears now or plan to do any mods to it, go with a 3.73 gearset.

 

So the guy still doesnt believe he did anything wrong... he claims that since i drove it off his shop how does he know i didnt mess it up or that i took it somewhere else on purpose just to get new gears. Does anyone know if there is somewhere or someplace i could go to file a claim against this guy?

 

Your local better buisness bureau is where to start.