I replaced my oil in my rear diff and I used Royal Purple 75-90 well my top fill screw is leaking I have it tighten pretty snug but not to snug, my question is should I crank it down till it stops and will it stop? or add some plumbers tape to the screw?

 

You can add the thread tape if you want to, I dont, I just crank them down until they stop.

 

Well I just got another three turns out of it and it did stop should be good!
Thanks

 

Good choice of gear oil! I'm running that stuff in my Tcase. I'll be putting it in the diffs next couple weeks or so.

 

Ya I have it my Transfer Case too but the wired part is my front diff has Lucas 80-90 long story but I was one quart short and had to leave town a.s.a.p and that was better than old oil! Don'T get me wrong Lucas is great stuff just like to have the same in both!

 

If you still have the plastic/rubber type fill plug. If you over tighten them, they will crack or break. If this happens, you might want to consider buy the newer style brass plug with a built in o-ring, they never fail or leak.

 

Well dang it is leaking again and the screw in tight as could be!!
I don't like the plumbers tape idea any other options I should consider?

 

DO you have the brass screw or the cheap plastic one?
If you do have the brass one then you can put the plumbers tape on the last few threads and it wont leak or get into the diff.

 

I have the plastic one on the front that one doesn't leak but I did the plumbers tape on the rear no more leak!

 

The fun parts comes when the plug breaks and you can't remove it, change them out on your time not when your plug breaks.