kittens

I had my car taken to the dealer for unrelated things and they said my differential was leaking. I looked under the car and didn't see anything on the pumpkin and couldn't find any fluid anywhere else. It rained recently so maybe the water washed it off so I will check again. But if there is a leak it is very small. Is this caused by a bushing breaking or something else? Can I leave it for now?

to accurately test for a leak can I put some cardboard under the car and check for fluid that way? or is it possible that it would just stick to the diff?

no fluid was seen under the car from the naked eye