Wheel Hub Differences

[LorenB667]

So, I've got a question about wheel hubs. I was putting the new rotors on my freshly cleaned up hubs. Once they were all together I noticed that the two hubs were not the same.

I've owned this car since 1995. The previous owner was the first owner (bought it brand new in '76). I have never replaced the wheel hubs. I don't think he did either. However, the hubs are different, see attached pictures. 

The question: Do these differences actually matter?

[Zed Head]

Have you checked the edge of the short one for damage?  I had a 78 hub that had that lip worn off due to a pebble getting trapped in the gap and grinding away.  It didn't matter much because the seal seat was intact.  Wipe the grease off and see if it's a machined surface or jagged.

[LorenB667]

It's completely clean (had to get it all clean to paint them!) and the edges are machined surfaces.

[Zed Head]

Do they look the same on the wheel side?

[LorenB667]

Yup, the only difference is the back side.

[Terrapin Z]

Just looking through the ones on eBay they look to all have the lip style. Like your second pic. 

The one looks shorter, perhaps it is like Zed says ground down. Could just be the picture. 

 

 

[LorenB667]

But the real question is: does it really make a difference for function?

[Zed Head]

41 minutes ago, Zed Head said:

It didn't matter much because the seal seat was intact.

The hub rides on the bearings.  So the bearing race seats and the seal seats are what matter on the inside.  I think that the lip is protection to keep dust and dirt away from the seal. 

When you put it back together look down at the gap and you'll probably see its purpose.

Edited May 24, 2023 by Zed Head

[Terrapin Z]

It looks like that lip rides over the step on the spindle. The seal is farther in. I agree with Zed a debris shield. 

Functionally it keeps dirt off the seal, which could potentially fail and release grease on the brakes. 

Edited May 24, 2023 by Terrapin Z
Purpose

[LorenB667]

Cool, then I'll machine them to match.

[Zed Head]

Seems like that lip might also grind away if the wheel bearings go bad.  Might be why it looks machined.

Why would you make a good one not-so-good, instead of just living with a not-so-good one?  The lip serves a purpose.

[LorenB667]

Do you know if that's steel or cast iron?