Differential Cover

mr84ss

Active Member
Joined
Aug 20, 2008
Hey there family. I went to change the rearend fluid on my 87 gn and noticed the 3/8 fill plug kinda rounded out by the previous owner. I dont even feel like messing with it if i dont have to. My question is, is there a cheaper option other than the $150+ diff cover with the fill plug in them?
 
From the factory, GN's didn't have any plug in the cover. The fill hole is in the front of the housing but I don't remember which side but it's easy to find. What I'd do is to find a way to remove the rounded plug, do your oil change and get a new plug in there and be done with it. As for removing the plug, if the square hole is too much rounded out, then have a nut welded onto it so you can put a socket or some "vise-grip" pliers to unscrew it and then get a new plug. There's definitely no need to replace the cover.
Good luck,
Claude. ;)
 
I forgot i sold my freaking welder to my buddy last year and i already done drained the rear. So welding the nut on idea is on hold. Is there anything else i can do until i get incontact with him

Sent from my LGMS631 using Tapatalk
 
I always managed to get them out with vise grips. Sometimes hamering in a allen or torx bit works :oops: I worked in a shop in the 80s and it was common. I would put a magnetic one back in.
 
I'll try that, thanks. Do they sell the magnet plug locally or its something that needs to be ordered from a vendor?

Sent from my LGMS631 using Tapatalk
 
Get an old 1/2 extension and start grinding the sides until it's slightly bigger than 3/8. Keep going until you can beat it in the plug.

Once it's out, you'll need to get a new one. I'm pretty sure it's 1/2NPT threads.
 
I forgot i sold my freaking welder to my buddy last year and i already done drained the rear. So welding the nut on idea is on hold. Is there anything else i can do until i get incontact with him

Sent from my LGMS631 using Tapatalk

I would remove the cover and install a Mr. Gasket transmission drain plug in the cover close to the same height as the plug in the hosing
 
Spray that diff bolt with PB Blaster every day, four times a day, for about a week. The do what Earl said. Using a little heat with a propane torch around the bolt will also help. I used this method to get the bleeder screws out of a caliper.

Also sprayed all brake lines at the proportion valve for a week, four times a day with PB Blaster....got the old brake fittings right off so I could put in a new brass proportion valve....didn't even round the hex fitting, either.
This is if you've got patience and time. Other wise, make a new hole with this:


DSC_0552.JPG

:D Bruce '87 Grand National
 
Top