I’m doing an oil change in the read differential (thank you ‘TheRock’ for the procedure!) and found that a white sealant was used on the plug threads at the factory. Should I clean and replace with new, or perhaps use Teflon tape? Does anyone know what the sealant is?

thanks
steve

 

You need Pipe Dope.

 

I'd use Teflon tape rather than pipe dope for automotive use, but it's a tapered thread so either should work.

 

I did neither, as it is a tapered drain plug. Driven the car many miles since the diff fluid change and no issues with leaking or seeping. Just my experience, do what you feel is best.

 

I was tempted to do the same, and appreciate you relaying your experience. Not worried so much about leaks as I am about a ferrous drain plug in contact with an aluminum housing. So, at the very least I'll use Teflon tape, as I have done so with classic cars for many years, with good results. However, I came across Permatex Aviation Form-a-Gasket Liquid Sealant, which is also impervious to oil. Has anyone had any experience with this?

 

Done same to one I had , could always slap a bit of grease round plug threads but other than that dudes way to fussy

 

For the record, I didn't use anything on mine either, but if I had it would have been teflon tape. I would not use any "form-a-gasket" type of sealer as I'd be concerned with it setting up too much and making removal difficult the next time. I just went through an unpleasant situation where pipe doe had set up too hard on some plumbing. Changing a utility sink faucet turned into tearing off the backsplash, cutting into the drywall, and replacing some piping just to achieve the original goal. I still need to grout the new backsplash

Anyway, it's a tapered thread so it wedges in place, and care needs to be taken to not overtighten.

 

If I use such a sealant I use this:



When applied looks just like the factory stuff.
When I changed the diff oil in my car I just bought new plugs. They are very cheap. They come with the sealant on them already.