8.75" Drain Plug

-
GoFish

GoFish

Have impressive member
Joined
Mar 29, 2007
Messages
765
Reaction score
8
Location
Los Angeles, CA
Has anyone here ever installed a drain plug in their 8.75" rearend? I seem to recall an article in Mopar Action or Mopar Muscle from a few years ago where they said you could drill and tap a hole and install a plug, but I can't seem to find it.

Any help would be appreciated!
 
Yes, very easy. Drill a 3/8" hole and tap it for pipe thread. I installed an aluminum plug with a recessed hex head (allen wrench) so it wouldn't interfere with a jack under the pig. Put locktite on it and run it in, but not super tight.

You will have to buy or borrow a 3/8 pipe tap, if you don't have one, buy a plug and some locktite.

VERY IMPORTANT: Make sure you don't put it under the ring gear, offset it a bit !!!!!

You can see it in the pic.
 

Attachments

  • plug 8 3-4.jpg
    179.3 KB · Views: 517
Thanks, Badsport!

Is it possible to do this without pulling out the pig? I'm lazy...:sleepy2:
 
I suppose you could, just be sure to avoid the ring gear! I would put some vaseline or grease on the drill bit to catch the shavings to minimize them going into the diff. Same thing when tapping. If there is gear lube in there obviously it will run out when you get through the case, and that will aid in flushing any small particles out.

Drill lightly so you don't blow through and break the bit. The housing material is not all that thick.

When you install the plug with the locktite on it make sure the area is reasonably dry.



EDIT: I said a 3/8 hole in the above post, I believe it will be smaller, 5/16 maybe for a 3/8 tap. Just look on the tap it should tell you.
 
Also when you are drilling be sure and keep your bit at a 90* angle to the surface that you are drilling so as not to end up with an oblong hole, you will never get the plug to fit right.
 
I used the 1/8" npt like the article.
1/8" npt use 21/64 drill bit. Don't run the tap all the way in because they taper and it will give it a better seal.

1/4" npt uses 7/16 drill bit
3/8" npt uses 19/32 drill bit
 
You must log in or register to reply here.
-

Back
Top