Just dawned on me that the fill plug in my 8.25 is probably as stiff and difficult as those factory grommets on the valve cover.

Is there a best way to get the thing out to just check/top off the gear oil without chunks falling into the diff? Will a heat gun help?

If not, is waiting until I can change the gear oil the way to go?

 

I'd just wait. Get a Lube Locker and gear oil and a new plug and go for it. Probably a $60 venture tax included, maybe less.

 

It is said that WD-40 will soften rubber. Guessing similar products will do the same.
If it works on the outside maybe you can fold up the flap and get some around the part that goes in the hole.
I don't see any reason if a small amount got in the diff it would do any harm.

 

Already have the rubber plug, but just have 1 qt of gear oil on hand. A Fel-Pro gasket is $3 at Rock Auto.

 

Just pop it out.

 

No need for a gasket. Blue RTV and a clean surface works fine.

 

I used this when I swapped my conventional gear oil for synthetic.

https://www.napaonline.com/en/p/PTW7651944

Had I know the Lube Locker gaskets existed I definitely would have went for one when I did the job.

https://www.lubelocker.com/product/llr-c825/

 

Anything wrong with Fel-Pro here?

 

If you don't use the Lube Locker I would just go with RTV.
But it should be fine though.
Thing with the Lube Locker is that you can remove the diff cover anytime you want and reuse the Lube Locker.
Guys who play in the water like these.
I like the idea because I could just go in there anytime I want for maintenance.
My Jeep being just a DD and all.
Like I said when I swapped out my diff fluid from conventional to synthetic had I known these existed I would have used one.

 

Ah, sounds good. Too bad Rock Auto does not show one for mine, it could go in with my massive parts order Friday.

 

Too bad.
Guys have said that they have had their diff covers off multiple times and were able to reuse the gasket without issue.