Axle Seal Concern

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cheezsnake

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The other day, I was getting the car ready to take out for the first drive this year. Jacked the car up to change oil and noticed a little fluid on the inner side of the rear tires. Pulled the drums and found grease oozing down from the axles. This afternoon, used a slide hammer to pull the driver side axle and seal. I noticed a couple things ... First, the surface where the seal stops does not look even all the way around -- it looks off center. There's much less surface on one side than the other. Second, the inside of that bore is nicked in a couple spots -- it catches a rag when I wipe the surface. I guess it could have happened when I pulled the seal, or it could have already been there...
IMG_3218.JPG IMG_3219.JPG
Has anyone run into this before? How concerned should I be about either of these causing a seal problem? The nicks are not on the face, but the back and inside of the bore. Can / should I lightly sand to remove the nicks?

Maybe the bigger question is does the axle seal actually need this surface to seal, or does it just seal around the outside as it is pressed in? Thanks.
 
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73 Grande 351C
71 Mach 1 429CJ
A couple of months back, I've found out that the trusted shop who rebuild my 73's axle placed the wrong seal and got oil in brakes. Cloud of smoke at stop light, ruined the newly installed shoes... great! Make sure to use the right seal for the inner radius. There are two.

You worry about the race/axle machining. But what matters is the kind of bearing that you have. There are quite a few different kinds for 9', some have the race that is pressed onto the end of the axle and that would be the kind where the race could turn and bite into the casing, but you would have heard it for sure. If this is the original rear end that came with the car, chances are high you have the modern bearing, all in one. If it has zero play, no blueish marks of heat, no abrasive marks on the outside and you feel zero resistance when you let it rotate. The bearing is ok.

My casing was smoother than yours, but if the bearing has no trace of abrasion you should not worry, as the outer part (the race) supposed to be locked/squeezed in place when you torque.

If there are marks, play, resistance then you need to replace it asap.

wrong.jpeg
 
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The inside bore of the housing where the seal sits doesn't matter since you can always use some black Permatex there. The shoulder where the seal stop not being square could be an issue because it can allow the seal to be partially offset or crooked. However, as long as the seal is square it shouldn't matter. If you are using a socket or seal installer you may be able to keep the seal square. The surface that will affect the seal the most is where the seal contacts the axle.
Alternatively you can use a bearing with and o-ring, which is what I have. With these you don't need a seal.
 

cheezsnake

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I like that bearing with the o-ring! My bearing looks ok. No marks or blueing. Spins smoothly. Guess all I can do right now is carefully clean up the burrs on the inner bore, and install the new seal. Just don’t understand why the changing angles from the brake plate to the inner bore. Would have expected to see more even circles I guess. Thanks for the advice!
 
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1973 Ford Mustang Mach 1 T5 Q-Code 4-Speed
The bore of my axle looked also a lot more worse than yours and seemed not to be centered. As it had still it's original coded seals on it I assumed that was factory. I cleaned the openings with fine grit. By hammering on the new seals I experienced that one went in just fine and the other only with a slight angle. That would have meant a leak if I just not saw that light angle. It took one more seal to get it right but I had to be extra careful.

So I think back in the day the factory milling was not premium as on so many parts but just right for function.
 

Aris

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1973 Mach-1
The outer ring of the bearing does not look healthy. Is the shaft bent or the bearing is installed incorrectly. I recommend replacing bearing and seal ...
 

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