I changed the diff fluid, gasket, and used some rtv on it and now two of the bolt holes are leaking a little.

Do I have to change the gasket or can I take the 2 bolts out and use rtv in the holes?

 

Hmm... last couple times my differential cover has been off, I haven't used the gasket and only used RTV. No leaks. I used the red high temp RTV.

http://www.bfranker.badz28.com/fbody/Maint15.JPG

It's going to suck if you have to take the cover back off... if it is just leaking out the holes, it might be worth a shot to take the bolts out, squirt a little brake cleaner in the hole to clean it good, then try some RTV on the threads and around the head area. Or, the best thing IMO but more work would be to get a clean container, drain it, put new RTV on it, then put it back together and the oil back in.

I'll move this over to the Drivetrain forum too

 

Yep I always just use straight silicone with no gasket on my diff cover, never had any problems doing it that way.

 

if its comming out the bolt holes, did you put sillicone completely around the bolt holes, or just on the outside

 

if its leaking out of the bolt hole then most likely you didnt put silicone around the bolt holes. Its just on one side and its now leaking tru to the threads. You can try putting silicone on the bolts but it may not fix it. Your probably better off just doing it again.

 

< same here - use silicone only