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Spindle Wear

sineden06

New Member
Joined
Jul 28, 2025
Messages
12
I just need a check on the wear of a spindle. The shoulder of the spindle, where the inner bearing seats up, should be squared off and not concave correct? The photo attached is what I am working with with.
Wondering if I should replace it or not. Any advice would be appreciated. Thanks.

IMG_1233.JPEG
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,622
Interesting. Is that a standard 76 or 77 disc set up?
Looks like a 5 bolt with curved arms, so I was curious.
By now, I should know the numbers off the top of my head, but I’m still decades away from that knowledge! 🙄😉

Been a while since I had my hands on a spindle, but it looks like the right shape. Just a bit rough.
Maybe you can clean it up a little bit? The larger diameter is where the seal rides. I don’t think the next edge inward should be squared off. If that’s what you’re referring to?
Should be curved as a stress reliever. At least that’s my theory and I’m sticking to it.

The smaller diameter that’s showing a bit of wear, can be smoothed down with some emery cloth or 400 grit sandpaper.
But check it first and see if your fingernail catches heavily on that edge. If it’s ever so slight, then you can clean it up. If it’s deep enough, I would get new spindle.
Cheap insurance…

If nothing else, this puts you back to the top and maybe someone with more detailed experience of spindles will give you their take on it.
 

SLOWnEASY

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Sep 26, 2022
Messages
519
Loc.
San Diego, Ca.
Is my red arrow pointing at the concave you're questioning? I don't know the answer, just trying to help clarify in my head.
 

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  • Shoulder.jpg
    Shoulder.jpg
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Oldtimer

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Jr. Member with Sr. moments
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Feb 4, 2005
Messages
1,795
Loc.
Sunnyvale, CA
And what does the bottom side of spindle look like? It looks like the bearing spun in a past life, and the bottom side would get the most abuse.
 

Apogee

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Bronco Guru
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Nov 26, 2005
Messages
6,345
Loc.
Tangent, OR
X2 on the spun bearing, as that's the most likely cause of the erosion on the shoulder where the inner race of the inner bearing sits on the spindle. At the end of the day, it just means that your hub/rotor sit inboard maybe .03" give or take relative to new, which isn't typically an issue with respect to brake function or stub axle fitment, as it will actually give you a little more axle stick-thru for the outer clip. You could machine off that lip, but it wouldn't change anything one way or another IMHO. I would double check the bottom of the spindle as suggested by Oldtimer above, and it looks like the top, buff it a bit with some emory cloth and move forward with the build, as it would need to be significantly worse for me to change out a spindle.
 
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