9 inch axle bearing issue. Need some help

[JSmall]

The seal requires about .045" of crush give or take, so you do need to suck it down in order for it to seal properly. The "skirt" of the seal around the bearing bulges out into the wall of the bearing counterbore to make a seal...without the crush, no bulge and no seal, hence all of the complaints of leaky SET20 bearings. If you look inside the seal prior to installation, you'll see rubber ridges that are about .06" tall that compress against the inner bearing race.

If your housing ends are exceptionally worn, damaged, scarred, etc, then it may never seal without some RTV or other measures.

I tend to run thicker retainer plates with SET20 bearings for less distortion, as even the stamped OE plates tend to wrap around the bearing/seal upon tightening. As for the gap, the assumption is that you have a ~10 gauge (.134") drum brake backing plate and gasket (~.020" FelPro #55036) between the retainer and housing end.

Tobin

Great info Tobin! I have the thick retainer plates from Yukon and the drum backing plate is used so I'm thinking I get the gaskets you mentioned and then suck it down. Will there be two gaskets per side?

 

[JSmall]

This shows the gasket listed twice for some reason.

 

[Apogee]

I'm 99% sure there was only one gasket on the F150 9" I just disassembled, and it was between the retainer and backing plate with the little lip towards the drum backing plate.

 

[JSmall]

I'm 99% sure there was only one gasket on the F150 9" I just disassembled, and it was between the retainer and backing plate with the little lip towards the drum backing plate.

Thanks! I will order one per side.

 

[BanditBronco]

0.045" is not very much, I would keep that in mind when crushing it down. Definitely less that the space that you are showing. I will send over some pictures in a few.

 

[JSmall]

0.045" is not very much, I would keep that in mind when crushing it down. Definitely less that the space that you are showing. I will send over some pictures in a few.

Thanks! I would really like to figure this out so it is done correctly.

 

[Apogee]

Too much crush and the bearing preload becomes too high, such that the axle won't spin without a lot of force, leading to excessive heat and premature bearing failure. Too little, and you run the risk of excessive axial end play during operation, which can also cause premature bearing failure. You're looking for the Goldilocks of bearing preloads, which is why I always figured Ford used a thin and somewhat flexible retainer plate, although I could certainly be wrong about that.

As you move towards more rigid aftermarket retainers, the preload becomes more critical since the retainer bracket is more rigid and less likely to deflect, increasing the bearing preload with all other variables the same.

 

[JSmall]

Few of the pictures from BanditBronco

 

[JSmall]

Too much crush and the bearing preload becomes too high, such that the axle won't spin without a lot of force, leading to excessive heat and premature bearing failure. Too little, and you run the risk of excessive axial end play during operation, which can also cause premature bearing failure. You're looking for the Goldilocks of bearing preloads, which is why I always figured Ford used a thin and somewhat flexible retainer plate, although I could certainly be wrong about that.

As you move towards more rigid aftermarket retainers, the preload becomes more critical since the retainer bracket is more rigid and less likely to deflect, increasing the bearing preload with all other variables the same.

That's why I don't want to guess on this. I would rather use all the correct parts if there is such a thing.

 

[Rymadd]

Went out an measured 3 different big bearing housings. 1 old and 2 new. All the bearing cups were right around 0.700" deep. one still had the set 20 outer races installed from the junkyard, they seem to be about 70 or 80 thou below the mounting surface, so if that's where yours are at then I think your fine running the set 20s in the old bearing cups.

Have you tried installing that old 31 spline axle in the housing with the stamped bearing retainer and seen if it fits flush?

 

[JSmall]

Went out an measured 3 different big bearing housings. 1 old and 2 new. All the bearing cups were right around 0.700" deep. one still had the set 20 outer races installed from the junkyard, they seem to be about 70 or 80 thou below the mounting surface, so if that's where yours are at then I think your fine running the set 20s in the old bearing cups.

Have you tried installing that old 31 spline axle in the housing with the stamped bearing retainer and seen if it fits flush?

I think I got .682 when I measured mine. I will double check when I get home. Thanks for taking the time to get those measurements.

I don't have the old races in and the stock shafts don't have the set20 bearings so I'm not sure what that would tell me.

 

[Rymadd]

I think I got .682 when I measured mine. I will double check when I get home. Thanks for taking the time to get those measurements.

I don't have the old races in and the stock shafts don't have the set20 bearings so I'm not sure what that would tell me.

Oh I saw a picture of an original axle with a set 20 bearing and a stamped ford bearing retainer, I thought that was yours. Figured if that fit It would be a retainer problem.

I got between 0.670" and 0.700 on all 3 axles but they were dirty so I figured they are all about the same. Still can't think of anything else, not sure why you would a need a spacer like some people are saying, other then the one you made out of the backing plate. Your making me want to go take an axle out of my truck haha

 

[JSmall]

Oh I saw a picture of an original axle with a set 20 bearing and a stamped ford bearing retainer, I thought that was yours. Figured if that fit It would be a retainer problem.

I got between 0.670" and 0.700 on all 3 axles but they were dirty so I figured they are all about the same. Still can't think of anything else, not sure why you would a need a spacer like some people are saying, other then the one you made out of the backing plate. Your making me want to go take an axle out of my truck haha

I have my stock axle with what looks like a set20 bearing and stock retainer. Brain fart...I can use the race from my new bearing and do a test fit. Thanks for the suggestion.

I wasn't able to look at the axle last night so I will investigate this weekend. Our measurements are close so I'm not understanding the issue either. The backing plate difference is the only thing that makes sense. I could buy another set20 and install it using the stock retainers to see if that works, but that doesn't sound like fun to me

 

[Rymadd]

I have my stock axle with what looks like a set20 bearing and stock retainer. Brain fart...I can use the race from my new bearing and do a test fit. Thanks for the suggestion.

I wasn't able to look at the axle last night so I will investigate this weekend. Our measurements are close so I'm not understanding the issue either. The backing plate difference is the only thing that makes sense. I could buy another set20 and install it using the stock retainers to see if that works, but that doesn't sound like fun to me

Looked like you already had the new bearing race in the housing, that's why I was thinking you could test the old axle and the only real difference should be the style bearing retainer. Might have to pull the 3rd member if the 31 spline doesn't fit inside the 35 spline locker. (You went 35 spline right?)

 

[JSmall]

Looked like you already had the new bearing race in the housing, that's why I was thinking you could test the old axle and the only real difference should be the style bearing retainer. Might have to pull the 3rd member if the 31 spline doesn't fit inside the 35 spline locker. (You went 35 spline right?)

You are correct and I test fit the old 31 spline shafts with the stock retainers and there is the same gap. I did go 35 spline and the 31 spline easily fit inside the ARB splines.

I'm going to keep it as is for mock up and when I tear it back down for paint, I might add a little thicker spacer.

 

[Yeller]

I've run into this before. Lots of variables for manufacturing. I can't remeber off hand who's housing ends I had the issue with. I made a spacer with a cardboard template. I know that rig is still out there running almost 10 years later.

 

[JSmall]

I've run into this before. Lots of variables for manufacturing. I can't remeber off hand who's housing ends I had the issue with. I made a spacer with a cardboard template. I know that rig is still out there running almost 10 years later.

That's reassuring. After I get the strut mounts welded on I will pull it and make a spacer. Thanks!

 

[DirtDonk]

Yeah, I don't think there's any question the gap for the current setup is correct due to the difference in retainers and the lack of any backing plate or gasket. Not necessarily from any variations in the components.
So the only question is, what do you use to fill the gap?

I'd hate to have to pull them off to install the old factory retainers as well, so a spacer sure sounds like the better option from way over here.;D

Paul