GMCforum: GMCnet » Final Drive Coughing Up Gear Oil

Home » Public Forums » GMCnet » Final Drive Coughing Up Gear Oil (Gear oil is coming out the vent.)

Show: Today's Messages :: Polls :: Message Navigator

Re: [GMCnet] Final Drive Coughing Up Gear Oil [message #344231 is a reply to message #344221]

Sun, 16 June 2019 07:45

powwerjon

Messages: 849
Registered: March 2013

Karma: -2

Senior Member

I have a cover on a FD that I have in storage that has that same vent setup on the cover. I suggest that it is a factory vent used on the FD used on the automotive version that was used on the Tornado and Cadilac Eldorado. Installation does not appear to be something that was added aftermarket.

http://www.gmcmhphotos.com/photos/general-pictures/p66469-img-24382.html

http://www.gmcmhphotos.com/photos/general-pictures/p66468-img-24371.html

J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Michigan

> On Jun 15, 2019, at 7:35 PM, James Hupy via Gmclist wrote:
>
> That vent tube is not factory. When installed, if it is subject to oil
> sign-off from the ring gear, and is not routed up towards the hatch cover
> before it points down, it will leak. Sounds like a fix that didn't.
> Jim Hupy
> Salem,Oregon
> 78 GMC ROYALE 403
>
> On Sat, Jun 15, 2019, 4:22 PM Jim via Gmclist
> wrote:

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Report message to a moderator

Re: Final Drive Coughing Up Gear Oil [message #344233 is a reply to message #343701]

Sun, 16 June 2019 08:56

JBO

Messages: 65
Registered: August 2012
Location: South Western Ontario

Karma: 0

Member

Jim K,
Thanks for the reply. You are correct on both observations. I am wasting my time and I do not have the knowledge on the venting of the final drive.

I did a nut and bolt restoration on this car and went over and rebuilt all the major components of it. I took the final drive and trans to a professional shop for them to go over and reseal. I did this because I lacked the time, tools and knowledge to do it myself.

I am now wasting a pile of my time trying to understand why a unit I sent out to professionals is now leaking. They obviously do not have an understanding on proper venting of the final drive either.

At the end of the day the OE cover should work as required without having to monkeying around. I went down the road of an improper gasket hoping that would be a quick and easy fix.

I now know that is not the problem. Your prior post in this thread explaining of the left handed vented seals has given me another situation to contemplate.

I appreciate your offer for a chat. I will definitely give you a call next week.

Cheers, Jim

Jim Owens, 78 Royale, Out skirts of Kitchener, Ontario

Report message to a moderator

Re: [GMCnet] Final Drive Coughing Up Gear Oil [message #344237 is a reply to message #344233]

Sun, 16 June 2019 10:29

James Hupy

Messages: 6806
Registered: May 2010

Karma: -62

Senior Member

J.R. you could very well be absolutely correct. I have a transmission out
of a early Eldorado, complete with final drive and engine, and it does not
have the hose vent. I have seen several final drives from unknown donor
vehicles that had the iron case drilled and tapped and fitted with tubing.
Those did not look factory. I just "assumed" that was an owner added fix.
Jim Hupy
Salem, Or.

On Sun, Jun 16, 2019, 7:12 AM Jim via Gmclist
wrote:

> Jim K,
> Thanks for the reply. You are correct on both observations. I
> am wasting my time and I do not have the knowledge on the venting of the
> final drive.
>
> I did a nut and bolt restoration on this car and went over and rebuilt all
> the major components of it. I took the final drive and trans to a
> professional shop for them to go over and reseal. I did this because I
> lacked the time, tools and knowledge to do it myself.
>
> I am now wasting a pile of my time trying to understand why a unit I sent
> out to professionals is now leaking. They obviously do not have an
> understanding on proper venting of the final drive either.
>
> At the end of the day the OE cover should work as required without having
> to monkeying around. I went down the road of an improper gasket hoping that
> would be a quick and easy fix.
>
> I now know that is not the problem. Your prior post in this thread
> explaining of the left handed vented seals has given me another situation to
> contemplate.
>
> I appreciate your offer for a chat. I will definitely give you a call next
> week.
>
> Cheers, Jim
> --
> Jim Owens,
>
> 78 Royale,
>
> Out skirts of Kitchener, Ontario
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Report message to a moderator

Re: [GMCnet] Final Drive Coughing Up Gear Oil [message #344242 is a reply to message #344237]

Sun, 16 June 2019 12:57

jimk

Messages: 6734
Registered: July 2006
Location: Belmont, CA

Karma: 9

Senior Member

I know they had the blowing out the gear lub on the Toro and Eldo earlier.
The dealer fix was to install a vent on the cover.
Also the factory lowered the oil fill by roughly 1" .
So if you have the correct cover, correct gasket , and correct left
seal,you should not have any issue.
The correct gasket must be used with minimal sealant as the sealant will
block the vent. The seal on the driver has 2 holes and a baffle.

On Sun, Jun 16, 2019 at 10:22 AM James Hupy via Gmclist <
gmclist@list.gmcnet.org> wrote:

> J.R. you could very well be absolutely correct. I have a transmission out
> of a early Eldorado, complete with final drive and engine, and it does not
> have the hose vent. I have seen several final drives from unknown donor
> vehicles that had the iron case drilled and tapped and fitted with tubing.
> Those did not look factory. I just "assumed" that was an owner added fix.
> Jim Hupy
> Salem, Or.
>
> On Sun, Jun 16, 2019, 7:12 AM Jim via Gmclist
> wrote:
>
>> Jim K,
>> Thanks for the reply. You are correct on both observations. I
>> am wasting my time and I do not have the knowledge on the venting of the
>> final drive.
>>
>> I did a nut and bolt restoration on this car and went over and rebuilt
> all
>> the major components of it. I took the final drive and trans to a
>> professional shop for them to go over and reseal. I did this because I
>> lacked the time, tools and knowledge to do it myself.
>>
>> I am now wasting a pile of my time trying to understand why a unit I sent
>> out to professionals is now leaking. They obviously do not have an
>> understanding on proper venting of the final drive either.
>>
>> At the end of the day the OE cover should work as required without
> having
>> to monkeying around. I went down the road of an improper gasket hoping
> that
>> would be a quick and easy fix.
>>
>> I now know that is not the problem. Your prior post in this thread
>> explaining of the left handed vented seals has given me another
> situation to
>> contemplate.
>>
>> I appreciate your offer for a chat. I will definitely give you a call
> next
>> week.
>>
>> Cheers, Jim
>> --
>> Jim Owens,
>>
>> 78 Royale,
>>
>> Out skirts of Kitchener, Ontario
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502

Report message to a moderator

Re: Final Drive Coughing Up Gear Oil [message #344434 is a reply to message #343701]

Sat, 22 June 2019 21:47

John Biwersi

Messages: 78
Registered: July 2006
Location: Maplewood,

Karma: 1

Member

Gentlemen, The 1968 Tornado and Eldorado was the first production year utilizing a spider gears type differential for the front wheel drive vehicles. The initial final drive cover for some of these vehicles had a vent pipe on the passenger side of the cover and the fill hole was at the same level as the 66 and 67 planetary final drives. At some point in time, GM changed the design of these covers by developing the 2 piece gasket for venting and they lowered the fill hole by approximately 1". They stayed with these arrangements through the 1978 front wheel vehicles. Since your car is a 1968, you may have a cover that has the vent pipe and the higher level fill plug. If you have the early design and you want to keep it absolutely original, then make yourself a dipstick such that you can measure the level oil and fill it 1" below the bottom of the fill hole. If you do not need to keep your vehicle absolutely original, then you can get any 69-78 Tornado or Eldorado final drive cover and the 2 piece gasket and your final drive oil should stop blowing out the vent. As a side bar, I have found that lowering the 3.21 planetary final drive oil level to match the same level as the 68-78 final drives helps prevent the oil blowing issue.

Report message to a moderator

Re: [GMCnet] Final Drive Coughing Up Gear Oil [message #371569 is a reply to message #344242]

Mon, 06 May 2024 16:45

pvfjr

Messages: 10
Registered: May 2019
Location: Mehama Oregon

Karma: 0

Junior Member

jimk wrote on Sun, 16 June 2019 12:57

I know they had the blowing out the gear lub on the Toro and Eldo earlier.
The dealer fix was to install a vent on the cover.
Also the factory lowered the oil fill by roughly 1" .
So if you have the correct cover, correct gasket , and correct left
seal,you should not have any issue.
The correct gasket must be used with minimal sealant as the sealant will
block the vent. The seal on the driver has 2 holes and a baffle.

Jim,

I know it's an old thread, but it's a good one. Can you explain why there needs to be two separate vents on this diff? I don't understand why the cover needs vented if the axle seal is vented--or vice versa. I've never had a differential that required seemingly redundant vents before.

Report message to a moderator

Pages (2): [ « ‹ 1 2]

Previous Topic:	California Fueling
Next Topic:	GMCnet/GMCforum Guidlines

Goto Forum:

-=] Back to Top [=-

Current Time: Sun May 19 04:19:16 CDT 2024

Total time taken to generate the page: 0.01403 seconds