Differential Fluid for my 72
Thread Starter
Team Owner
Joined: Feb 2005
Posts: 32,519
Likes: 1
From: central America
St. Jude Donor '08-'09
Differential Fluid for my 72
Okay guys and gals,
during a routine inspection, I noticed that the rear part of my exhaust had an oily like film on it...much to my chagrin, I noticed that the back part of my differential is leaking fluid (gasket area)
, 80W-90 I imagine. I'm going to be moving in the next couple of months, and can't really afford to take it apart right now(I hate limping things through but I don't see anyway around it
). I'd just like to add some oil and keep it topped off until I do my complete suspension redo this winter or next spring. Is there anything special about the fluid? Will straight GL-5 80w90 do the trick, or do I need some sort of special additive. The Haynes manual suggests a GM part number (can't remember it off the top of my head) but I don't always trust what I read in those.
tia for any responses,
trw
there are no loud noises yet from the rear end, and I want it to stay that way!
during a routine inspection, I noticed that the rear part of my exhaust had an oily like film on it...much to my chagrin, I noticed that the back part of my differential is leaking fluid (gasket area)
, 80W-90 I imagine. I'm going to be moving in the next couple of months, and can't really afford to take it apart right now(I hate limping things through but I don't see anyway around it ). I'd just like to add some oil and keep it topped off until I do my complete suspension redo this winter or next spring. Is there anything special about the fluid? Will straight GL-5 80w90 do the trick, or do I need some sort of special additive. The Haynes manual suggests a GM part number (can't remember it off the top of my head) but I don't always trust what I read in those.tia for any responses,
trw
there are no loud noises yet from the rear end, and I want it to stay that way!
Thread Starter
Team Owner
Joined: Feb 2005
Posts: 32,519
Likes: 1
From: central America
St. Jude Donor '08-'09
It was overfilled!
Okay, so I buy some 80w90, getting ready to add some oil to my differential...pull the drain plug, and rear end oil starts draining out! My differential was overfilled! and has probably been like that for some time. Do any of you think that there's been any permanent damage done? Gosh I hope not.
BTW, the oil looked almost grey, but didn't smell bad or burnt. No metal fillings either, that I could see.
trw
and has probably been like that for some time. Do any of you think that there's been any permanent damage done? Gosh I hope not.BTW, the oil looked almost grey, but didn't smell bad or burnt. No metal fillings either, that I could see.
trw
Tech Contributor
Joined: Aug 1999
Posts: 15,188
Likes: 4,010
From: Connecticut, USA
You're ok. If you have a problem you'll know it. As long as you don't have a leak by the side yokes or pinion seal you're good. 
Gary
PS Use any 90 wt gear oil but use the Gm additive otherwise the clutches will start knocking around corners.
Gary
PS Use any 90 wt gear oil but use the Gm additive otherwise the clutches will start knocking around corners.
