had my pinion gasket replaced 2 days ago on my 06 GT, but they did not fill up the rear with lub so I think I trashed the rear on a car that has less than 8500 miles on it.

 

If they didn't have the rear cover off fluid loss would be minimal. Check your diff fluid level. It should be about 1/4" below the plug hole.

 

didn't get the chance they are replacing lots of parts in the differentional, that were torn to sheds when I drove it in.

 

no leaks here except for the brake fluid

 

Lime GT is correct. The pinion seal is quite high on the housing and there would be very little oil loss. Certainly not enough to damage anything. As suggested just pull the fill plug and make sure the oil is just about up to the hole and you're good to go.