I took the cover off my front diff to change the fluid. 2001 Cherokee 4x4 with 85,000 miles. The oil was clean but the cover and the gears inside are covered with a layer of black film. Is this normal? I'm putting synthetic back in with Lube locker gaskets. There was no metal in the oil or bottom of the case.

 

Normal. Spray the innards down with brake-parts cleaner before adding new oil.

 

FYI RTV works perfect, ya I'm cheap.

 

I used the black goo they sell at my work it's Mercedes sealant I couldn't get the cover off my 35 when I was done. I used it on my 30 and my8.25 no leaks from the cover just everywhere else on the 30. The nasty film is normal a lil bit of metallic sparkle is also normal if your getting large shavings or missing teeth on the gears then something is wrong.

 

I just spent 30 minutes scraping all the RTV crap off. I wan't have to do this next time!

 

Next time use a razor blade, or a brass wire-wheel on your drill.

 

I had an orange rtv on mine. Drill and wire wheel took it off the cover well. And a razor blade on the axel.

 

Yup. Next time you'll be scraping gasket!