So I noticed that my diff was leaking, so I took out the top plug and gear oil spurts out, probably half a quart or so. Looks like the place that put in my LSD overfilled it since it should only be filled to the level of that upper plug. I'm wondering if this could have caused any damage, other than breaking the seal somewhere? I'll most likely open the whole thing up and reseal it - what is used to seal up the pumpkin, or is it just a gasket or something?

 

you can use rtv sealant from the auto parts store. i've done dozens of them that way.

 

kinda curious how they even got it filled that much.

 

somebody at the repair you took your car to has really quick hands!

 

It's possible to overfill a diff by having a car not leveled out properly on the lift. If the nose is slightly down, the level at the diff fill hole changes and you can overfill it. That also applies the opposite way in checking the diff- was your car absoutely level when you pulled the plug?

In my experience, a slight overfill shouldn't hurt anything. If you had a specialized LSD installed, you may want to check the installation instructions to be sure that it doesn't call for additional gear oil.