I'm finally getting around to changing the differential fluid in my 99 Ram Van, and I came across something curious in the factory service manual: it says to use a bead of silicone sealant when reinstalling the differential cover. Nothing about a gasket, just silicone sealant (which I assume would be black RTV).

Anybody out there done this job before? Did you use RTV or a gasket (or both) when reinstalling the differential cover?

I want to get this done right--my van doesn't have any leaks, and I'm not interested in creating one!

 

RTV will be fine.

 

One or the other but not both, Permatex ultra black has always worked well for me. For gaskets I like the lube locker gaskets since they are reusable.

 

No gasket required, just the RTV. They make an RTV especially for differentials and gearboxes, it's what I used and had no issues with it.

https://www.permatex.com/products/ga.../?locale=en_us