Author Topic: HELP! Leaking Final Drive  (Read 367 times)

Offline danjarrett1

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HELP! Leaking Final Drive
« on: January 02, 2018, 05:41:50 PM »
I have a 1974 Eldorado convertible, affectionately known as “CADZILLA” I bought the car a few months ago expecting a few repairs, and so far, everything I’ve found has not been that much of a surprise. I am struggling  with one issue that I cannot find any documentation on. I bought the GM 74’ Service manual, ( it’s a well written manual in my opinion) but there’s very little about the final drive. I have a fair amount of leakage around the whole pumpkin, it may be that the output shaft seals are leaking but it’s hard to know exactly where the leak is because the differential cover is leaking.  Here's the dilemma, the previous owner gobbled a ton of sealant on it but I'm not sure that it's right, does anyone know if there is an applicable gasket for the cover or is it sealed only with silicone sealant?
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline The Tassie Devil(le)

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Re: HELP! Leaking Final Drive
« Reply #1 on: January 02, 2018, 05:52:00 PM »
The cover can be sealed with a Silicone, if you don't have a gasket, as there is supposed to be a gasket there.   I use Loctite 5900  silicone, as this stuff is also compatible with Auto Trans fluid.

The side seals are replaceable, but one must remove the axles to gain sufficient room to access these.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Offline danjarrett1

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Re: HELP! Leaking Final Drive
« Reply #2 on: January 02, 2018, 06:58:10 PM »
Thanks for the reply, I intended to try to locate a gasket or maybe even a part number from a diagram for a gasket....using correct  silicon formed gasket is an option, and in the end, will likely be the solution. Just wondering if anyone I. The Eldo word knows if there was a gasket there when this thing left Detroit!
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline The Tassie Devil(le)

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Re: HELP! Leaking Final Drive
« Reply #3 on: January 02, 2018, 08:06:42 PM »
Yes, there was a gasket.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Offline danjarrett1

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Re: HELP! Leaking Final Drive
« Reply #4 on: January 02, 2018, 09:44:43 PM »
What is the gasket refered to? The only gasket that I can find is the replacement gasket between the final drive and the transmission! I cannot find a reference to a differential cover gasket. Anyone have any idea where to find one? OPGI doesn’t t recognize it, neither does Caddy Daddy. Any other resources I should check??
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline The Tassie Devil(le)

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Re: HELP! Leaking Final Drive
« Reply #5 on: January 02, 2018, 09:57:16 PM »
I too could never find a replacement, but the Shop Manual refers to one as a Seal Cover Gasket.

Plus, the Shop Manual makes note of sending the Third Member back to the Dealer for the Factory to service it.   The internals are not designed to be rebuilt by outside shops.

Bruce.  >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Offline Bob Hoffmann CLC#96

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Re: HELP! Leaking Final Drive
« Reply #6 on: January 02, 2018, 10:13:10 PM »
It's called a Final Drive Cover gasket. Group # 5.399 Part # 231285 in the MPL. Might be available GM or try NAPA.
Bob
1941 62 coupe custom maroon
1970 DeVille conv. triple black
1968 Eldorado slick top ,white/red interior
2015 Holden Ute HSV Maloo red/black interior.
             
Too much fun is more than you can have.

Offline kkkaiser

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Re: HELP! Leaking Final Drive
« Reply #7 on: January 02, 2018, 10:25:25 PM »
fel pro seems to have a lot of stuff,, gaskets etc,, funny i needed a oil pump gasket, and when i called them, they said they didnt have one, but the DID have one that was included in a package of engine gaskets,, so, i goes you have to be broad with your do yo have questions

Offline danjarrett1

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Re: HELP! Leaking Final Drive
« Reply #8 on: January 02, 2018, 10:29:13 PM »
Thanks, I’ll try a GM source using the MPL part number.
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline danjarrett1

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Re: HELP! Leaking Final Drive
« Reply #9 on: January 02, 2018, 10:54:25 PM »
FOUND ONE..... Mahle/Victor Gasket on Amazon. P23883 Axle Housing Cover Gasket is how it is described, $12.  Thanks all
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline "Cadillac Kid" Greg Surfas 15364

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Re: HELP! Leaking Final Drive
« Reply #10 on: January 02, 2018, 10:56:10 PM »
Dan,
I might suggest that before you start chasing leaks, clean the area completelt to bare metal (or paint if it is there) and drive it a couple of blocks.  You should then be able to determine the source of any and all leaks.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline danjarrett1

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Re: HELP! Leaking Final Drive
« Reply #11 on: January 02, 2018, 11:01:39 PM »
That’s exactly what my plan is! I intend to clean it thoroughly, Drive it and try to identify the leak. I’m confident that the cover seal is seeping, my concern is that the drive out put shaft seals are leaking as well..but clean and drive will tell
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline bcroe

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HELP! Leaking Final Drive
« Reply #12 on: January 02, 2018, 11:33:55 PM »
My money says its not the axle seals.  Some of the replacements
are not really up to the standard of the originals.  Is it gear lube
or trans fluid? 

Note also, there is a pair of seals between the trans and the
final drive, and a small vent in the area.  Might have a piece
of wire sticking out.  Bruce Roe

Offline danjarrett1

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Re: HELP! Leaking Final Drive
« Reply #13 on: January 02, 2018, 11:41:39 PM »
Good suggestions! I’ll look into those areas. Really need to get is all cleaned up then drive it and see what manifests
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline Jeff Rose CLC #28373

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Re: HELP! Leaking Final Drive
« Reply #14 on: January 03, 2018, 11:25:52 AM »
Check to be sure that vent isn't plugged. It could be mostly dry but leaking when the pressure builds up.
Jeff
Jeff
CLC #28373
1970 Coupe DeVille
1955 Series 62

Offline danjarrett1

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Re: HELP! Leaking Final Drive
« Reply #15 on: January 03, 2018, 11:29:07 AM »
YES! A plugged vent will cause the case to be pressurized and blow seals, had that happen on a transmission once!
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline Bob Hoffmann CLC#96

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Re: HELP! Leaking Final Drive
« Reply #16 on: January 03, 2018, 12:53:31 PM »
FOUND ONE..... Mahle/Victor Gasket on Amazon. P23883 Axle Housing Cover Gasket is how it is described, $12.  Thanks all
Do you have a link??
1941 62 coupe custom maroon
1970 DeVille conv. triple black
1968 Eldorado slick top ,white/red interior
2015 Holden Ute HSV Maloo red/black interior.
             
Too much fun is more than you can have.

Offline danjarrett1

  • CADZILLA
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  • Name: D Jarrett
Re: HELP! Leaking Final Drive
« Reply #17 on: January 03, 2018, 12:59:11 PM »
Amazon. Can’t forward the link from here found it on amazon
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline TJ Hopland

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Re: HELP! Leaking Final Drive
« Reply #18 on: January 08, 2018, 08:27:48 AM »
The original gasket is 2 layers and one of the gaskets has a slot in it that is the vent.   If the last person just sealed it with sillycone its not vented so when it gets hot it just looks for any place to escape it can find. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline fishnjim

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Re: HELP! Leaking Final Drive
« Reply #19 on: January 08, 2018, 08:44:01 AM »
If the mileage is high and the bearings and seals are worn, then gaskets won't help (unless it's just the diff cover leaking).   Seepage around the pinion seal is a tell tale of gear wear and loss of proper lash.