Hello all. I am looking for some advice as to whether this pinion needs replaced. Pictures are attached.

The differential was making a roaring noise, so I diagnosed it to be the pinion bearing. After I got it taken apart, I noticed that the pinion itself has a few chips at the end of the grooves. There isn't any damage to the grooves themselves and the ring is in great shape.

Do you think I need to replace the pinion, or should it be fine since there's no other damage except on the ends?

Thanks in advance for the replies!

 

definitely needs bearings

 

I'd change them.

 

If you ever wanted to put a different gear in, now is the time to do it, that pinion will chew on the ring gear until one or both grenade.

 

Hi all,


Thanks for the advice. Ended up taking it to a mechanic who thought the pinion itself would be ok, since the chips were outside of where the pinion and ring touch.

We ended up replacing the pinion bearings and races. That seems to have fixed the problem, since we went from a load howling noise in the rear end to completely silent now.

 

I'm curious as to why the pinion looked like that in the first place.

 

I'm not sure. There wasn't any metal pieces in the fluid when we drained it, but that just means the fluid has been changed before. There were a lot of chunks taken out of the inner pinion bearing and race. Maybe those metal pieces damaged the pinion?

The pinion was also very loose. When we took it off, the pinion nut was almost hand loose and the pinion could easily be wiggled around in the case. Maybe being loose caused it to bang around and get damaged.