The mechanic says I need a drive shaft bearing and pinion seal and that the differential is leaking, there are no signs of leaking?

Hi,

It isn't odd for a pinion seal to leak. If it isn't a bad leak, it can wait, but you need to check the differential fluid to make sure it doesn't get low.

I attached two pics below. If you look under the rear of the vehicle, follow to where the drive shaft attaches to the rear differential. See pic 1 for a pic of the differential. I circled where the seal is located. Inspect that area to see if it is wet or if it has any signs of a leak.

Pic 2 shows an exploded view of the differential. I highlighted the seal he is referring to for your reference.

Let me know if you have questions and if this helps.

Take care,

Joe

See pics below.