Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: 39BuickCoupe on October 30, 2021, 09:47:06 PM

Title: front differential 1972 Cadillac Eldorado
Post by: 39BuickCoupe on October 30, 2021, 09:47:06 PM
Fill and drain plug on 1972 Cadillac Eldorado front differential. What is the fluid replacement capacity?
Title: front differential 1972 Cadillac Eldorado
Post by: 39BuickCoupe on October 30, 2021, 10:22:05 PM
Location of fill and drain plug on 1972 Cadillac Eldorado front differential. How many quarts of gear oil does it take to refill after draining front differential?

Thanks,

Jeff
Title: Re: front differential 1972 Cadillac Eldorado
Post by: TJ Hopland on October 30, 2021, 11:29:57 PM
I don't think I ever saw a factory cover with a drain plug.   Its like most GM diffs of the era where they apparently expect you to pop the cover off to change it.    Fill plug/level check plug is about 1/3 the way up the cover which points forward.   GMC RV people I think made a finned aluminum cover with a magnetic drain plug.

Note that the gasket for the cover was a 2 piece design with a thin paper layer then a thicker layer that incorporated a vent so if you didn't have the gasket and just gooped it up with RTV you could end up with leaks because it can't vent properly.

I don't recall the capacity but its not much.  Just short of 2 quarts is what I remember.

If it was me and the gasket wasn't leaking I would consider just sucking out what you could and assuming no signs of metal just refill it with fresh stuff and call er good.   

This is what I use for jobs like this and about a million other jobs,  its a very handy tool to have around.
(https://www.northerntool.com/images/product/400x400/332/332260_400x400.jpg)

https://www.northerntool.com/shop/tools/product_465467_465467?cm_mmc=Google-LIA&utm_source=Google_LIA&utm_medium=Fuel%20Transfer%20%2B%20Lubrication%20%3E%20Oil%20Extractors&utm_campaign=LiquiVac&utm_content=332260&gclid=EAIaIQobChMIod-yj9rz8wIVWm1vBB0TtAJ4EAQYAyABEgIH-_D_BwE&gclsrc=aw.ds 
Title: Re: front differential 1972 Cadillac Eldorado
Post by: The Tassie Devil(le) on October 31, 2021, 02:02:52 AM
No drain plug.   Just a filler.

The capacity is 4 Pints.   But, also the level must not be higher that 1/2" below the filler hole.

Bruce. >:D
Title: Re: front differential 1972 Cadillac Eldorado
Post by: Big Fins on October 31, 2021, 02:53:25 AM
The gaskets are readily available. Easy to pop the cover off and change the lube. It takes longer to get the front end up on stands.
Title: Re: front differential 1972 Cadillac Eldorado
Post by: TJ Hopland on October 31, 2021, 10:18:55 AM
I hadn't looked for gaskets for a while,  I just remember reading here that at least for a while the only ones you could get were incorrect.  I know it was quite a while ago so its good to hear that someone started making the correct set again.

4 pints?  That's like 2 1/2 quarts.   I remembered ending up with a partial I guess I just didn't remember how many I started with.  I may even still have that partial waiting to top it off even though it was over 20 years ago that I did it.
Title: Re: front differential 1972 Cadillac Eldorado
Post by: The Tassie Devil(le) on October 31, 2021, 07:44:26 PM
I would have thought that 4 pints would be 2 Quarts.

I was going off the Shop Manual, which gave the figure of 4 Pints as US Pints.

The Shop Manual refers to the RWD Differential as requiring 5 Pints.

Bruce. >:D
Title: Re: front differential 1972 Cadillac Eldorado
Post by: cadlove on October 31, 2021, 10:11:33 PM
In US it is indeed 4 pints of 80W/90 GL-5. Don't you have a Cadillac workshop manual?

I've handled early seventies Eldorados for years, in the final drive steel pan they have a drain plug.
Title: Re: front differential 1972 Cadillac Eldorado
Post by: The Tassie Devil(le) on November 01, 2021, 12:40:15 AM
Sorry but there is no drain plug on the cover of the FWD Third Member.

Bruce. >:D
Title: Re: front differential 1972 Cadillac Eldorado
Post by: Big Fins on November 01, 2021, 03:37:40 AM
No drain plug on mine either. Just the filler/inspection plug.
Title: Re: front differential 1972 Cadillac Eldorado
Post by: TJ Hopland on November 01, 2021, 10:03:32 AM
Interesting that the front and rear drive were that close in volume.   The RWD's look much larger and are not nearly as full.   You open up one of the Eldo ones and there isn't hardly any room for fluid because its packed full of gears and such.

Has anyone actually seen Pints used anywhere other than this era of automotive?   Was it all American cars or just GM?  Is it used in medical?   Seems like I have heard pint of blood in tv and movies.  Is or was it used in cooking?