Final drive seals

Post your technical questions and information here.
Mikel
Posts: 134
Joined: Tue Aug 11, 2009 7:26 am
TOA Membership Number: 100
Location: New Haven, CT

Final drive seals

Postby Mikel » Sat Feb 10, 2018 7:26 am

http://www.appliedgmc.com/prod.itml/icOid/1881

Is this TH425 final drive seal supposed to be vented, or is the final drive vented somewhere else? I suppose there has to be some way to relieve internal pressure once temperature rises...?
Thanks.

Mikel

User avatar
Otto Skorzeny
Posts: 1721
Joined: Fri Feb 28, 2014 12:41 pm
TOA Membership Number: 0
Years Owned: 1966 Toronado

Re: Final drive seals

Postby Otto Skorzeny » Sat Feb 10, 2018 8:13 am

I've never worked on mine but I've never noticed a vent tube or any other place to vent like you find on most axles or differentials so that sounds logical.

Applied GMC knows their stuff so I'd trust that to be the correct seal.

Mikel
Posts: 134
Joined: Tue Aug 11, 2009 7:26 am
TOA Membership Number: 100
Location: New Haven, CT

Re: Final drive seals

Postby Mikel » Sun Feb 11, 2018 5:43 pm

Thanks.

User avatar
Otto Skorzeny
Posts: 1721
Joined: Fri Feb 28, 2014 12:41 pm
TOA Membership Number: 0
Years Owned: 1966 Toronado

Re: Final drive seals

Postby Otto Skorzeny » Wed Feb 14, 2018 10:23 pm

Hi Mikel,

I just saw this in another thread on the subject:

viewtopic.php?f=7&t=1559

Final drive leak is solved. It was my own problem. All the replacement seals for the left shaft are made for the later venting system, which means they have two small holes in the outside steel ring of the seal. The '66 final drive is vented through a hole in the the left shafts flange securing bolt. In the flange on the outer side there is a checkvalve and the flange itsself has two small holes in it.
Now said hat the newer style oil seal must be installed with the holes in the upper most position, mine were in the lower most position..;-(

I didn't care about the holes , didn't recognize them as what their purpose was and didn't pay any attention to them 'cause I never saw an oil seal with a venting option... and I saw a lot of them.....

I just had a chance to close them with epoxi, didn't even have to remove a single bolt... the Final drive doesn't leak anymore...
Harald

Mikel
Posts: 134
Joined: Tue Aug 11, 2009 7:26 am
TOA Membership Number: 100
Location: New Haven, CT

Re: Final drive seals

Postby Mikel » Sat Feb 17, 2018 4:31 pm

Thank you.

Another problem - After resealing my 75ish final drive, I noticed that the driver's side output flange has about 0.040" of side to side play, and about the same in in-out play. I can see the driver's side diff gear moving with it.

I have a couple of '66 final drives and that flange is rock solid in both of them. But these have planetary differentials, vs a conventional one in mine. Is this normal?

Thanks.


Return to “Technical Talk”

Who is online

Users browsing this forum: No registered users and 21 guests