Installing Axle Housing Seals: How Deep?

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charliec

charliec

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'68 Dart, 8-3/4 Posi
I'm re-assembling after MANY years, so a lot is fuzzy. When installing the inner axle seals, how deep should I expect them to set? The shop manual just says to install them...no instruction. Do I just keep tapping them till they don't go any more, or is there a rule of thumb as to how far in they should go?
 
I'm just doing this today myself. I believe you tap them in until they stop, that is where the ones I took out were seated. If you look into housing from outer ends, you will see the machined recess for the seal, it can only go in that far.
 
Put some grease on the spring side so that little bugger don't pop off the seal.

And yes, there is a machined ridge that they butt up to.
 
Hope you replaced the outer seals as well! Most folks miss this!

Unless I had recently done this I purchase new retainers with the outer seals already installed. They usually come with the foam gaskets, brake backing plate gasket and inner seals in a kit!
 
1969383S said:
Hope you replaced the outer seals as well! Most folks miss this!

Unless I had recently done this I purchase new retainers with the outer seals already installed. They usually come with the foam gaskets, brake backing plate gasket and inner seals in a kit!
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What kit is this? I couldn't find the foam seals, so I bought gaskets for both sides of the backing plates.
 
cpearce said:
What kit is this? I couldn't find the foam seals, so I bought gaskets for both sides of the backing plates.
Click to expand...

NAPA sells these service kits! Complete overhaul kit - Minus the bearing.
 
1969383S said:
NAPA sells these service kits! Complete overhaul kit - Minus the bearing.
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Cool, thanks! Funny Napa couldn't help me with that the other day, I had to order everything individually. Another funny thing, the brake nail and spring kit came with 2 rubber vent plugs, each backing plate has 2, so you need 4.
 
To replace the outer seals you have to replace the bearings.... The outer seals are only supposed to retain the grease that should be packed in to the bearing... If the inner seal does it's job & retains the gear oil the grease generally isn't a problem... Make sure to thoroughly clean the bearings & pack them with good quality bearing grease & unless you see leakage I wouldn't replace the outer seals...
Personally I use a grease needle to inject grease in the bearings...

https://www.amazon.com/dp/B01N41VKS3/?tag=fabo03-20
 
1WildRT said:
To replace the outer seals you have to replace the bearings.... The outer seals are only supposed to retain the grease that should be packed in to the bearing... If the inner seal does it's job & retains the gear oil the grease generally isn't a problem... Make sure to thoroughly clean the bearings & pack them with good quality bearing grease & unless you see leakage I wouldn't replace the outer seals...
Personally I use a grease needle to inject grease in the bearings...
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I disagree.

Every issue I have ever had with 8.75 housing's had the same problem, Be it my trucks or cars.

Yes the Bearing should be packed in grease on assembly! If either seal fails you have issues.

If you think replacing the inners are the fix "all" then you may want to rethink things. If the inner is tired then the outer is the same!

You will be back into it in short order with that thinking! Do it once and do it right! JMO!
 
1969383S said:
I disagree.

Every issue I have ever had with 8.75 housing's had the same problem, Be it my trucks or cars.

Yes the Bearing should be packed in grease on assembly! If either seal fails you have issues.

If you think replacing the inners are the fix "all" then you may want to rethink things. If the inner is tired then the outer is the same!

You will be back into it in short order with that thinking! Do it once and do it right! JMO!
Click to expand...

I've been turning wrenches professionally for forty years, you do it your way, I'll do it mine... Most inner seals leak due to damage or a plugged housing vent..

Recently installed seal often fail because the garter spring popped off when installing the new seal, or the seal housing got distorted... Or the seal wasn't driven in fully and the bearing retainer ring rubbed on the seal...

Grease is heavy and generally isn't difficult to keep inside the bearing, especially considering it is being thrown outward by centrifugal force and the area where the seal lip rides is the inner most point of the axle shaft....
 
1WildRT said:
I've been turning wrenches professionally for forty years, you do it your way, I'll do it mine... Most inner seals leak due to damage or a plugged housing vent..

Recently installed seal often fail because the garter spring popped off when installing the new seal, or the seal housing got distorted... Or the seal wasn't driven in fully and the bearing retainer ring rubbed on the seal...

Grease is heavy and generally isn't difficult to keep inside the bearing, especially considering it is being thrown outward by centrifugal force and the area where the seal lip rides is the inner most point of the axle shaft....
Click to expand...


Good for you, I have been at it even Longer! If you see differential fluid in your brakes "Talking 8-3/4 you better replace both seals and service the bearing!

Otherwise you will likely be doing it again in short order! JMO!
 
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