Replacing S30 Rear Wheel Bearings

[Zed Head]

Don't forget the other two seating surfaces, besides the distance piece. One on the axle and one on the companion flange.  A piece of grit or a metal shaving could have a big impact.  Edit - the distortion might not happen until the nut is torqued and the inner race gets cocked.

Edited April 26, 2019 by Zed Head

[the_unknown]

We had the "bad" axle in and out more than a few times, then switched axles and the problem went away. We installed the bad axle in the other good housing and it locked it up too. So it's definitely an issue with the stub axle, bearing, or a small chance it's the distance piece.

[Zed Head]

The bearing on the wheel side is staying on when you do the swaps right,press fit on the axle journal?  So you have either the axle or the bearing as the problem, probably.

There's much discussion about damaging races, "brinelling", by pulling on the outer race,if the inner race is pressed on.  But during installation, you're pushing backward on the outer race as you tighten the nut and they seem to survive  Seems like you could separate the bearing from the axle and test both independently.  If you had lots of free time...

[the_unknown]

5 minutes ago, Zed Head said:

The bearing on the wheel side is staying on when you do the swaps right,press fit on the axle journal?  So you have either the axle or the bearing as the problem, probably.

There's much discussion about damaging races, "brinelling", by pulling on the outer race,if the inner race is pressed on.  But during installation, you're pushing backward on the outer race as you tighten the nut and they seem to survive  Seems like you could separate the bearing from the axle and test both independently.  If you had lots of free time...

Yup bearing is staying attached to the stub. I will likely test everything out once I get it running and then reach out to timken if the bearing was faulty. I'm really curious now as to what has failed.

[Captain Obvious]

If I was desperate, I believe my conscience would allow me to re-use the outboard bearing even after pressing the stub back of once it had been installed. The outboard bore is sized such that it's a press fit, but not a uber tight one. That's why the slide hammer works. If it were a real tight press fit, you'd need hydraulics to take it apart because a slide hammer wouldn't cut it.

However, I'm not sure I'd do that if they'd been assembled and disassembled ten times.      In any event, it's academic since new ones are on order.

I also really really doubt it's a bearing issue. Even without seeing the parts, I'm at 90% sure the issue is the stub axle and not the bearing.

Just for the sake of the investigation, I hope you can eventually conclusively determine exactly what was going on.  I like the forensic stuff!

[the_unknown]

I think it's the stub too. Being a scientist, i love the forensics stuff too. If it is a bearing issue, I am going to measure every little part of it and see just how much a difference made. if it's off by less than a thousandth, I will be very surprised by the precision required to make that whole system work.

[Zed Head]

I'm leaning towards a seating issue.  Four surfaces, any one of which could cause a problem.  The inner races and distance piece form a solid tube of steel connecting the flanges together.  Might even be possible to take the bad axle and bearing set and use a pipe and a press to be sure that the inner race is fully seated.  Pound it down on the wheel flange surface.  Then reinstall and see if torquing still causes the problem.

Don't really the use of the nut as the final press of bearing installation.  It's not "right".  Aesthetically displeasing.  I haven't done one but if I did I'd try to knock each race in to place separately if I could figure out a way.

[the_unknown]

We used a hydraulic press to seat everything and inspected all mating surfaces. I'm 99.9% certain it isn't a seating issue at this point. 

[Zed Head]

Being certain before knowing just makes a person less likely to see what's there.  Cognitive bias.  No offense.

If you consider it mechanistically, like what, exactly, is touching and binding, then a race misalignment seems like a good possibility.  The bearings have play in them from the start, properly installed, you can lift your wheel up and down a noticeable amount when the back end is lifted.  And push-pull it in and out.  Seems like there'd have to be quite a bend in the shaft to get a bend-bind.  A short distance piece, giving zero end play, and any type of misalignment will be magnified.

Might be interesting to measure end play while you're torquing.  If it goes to zero before you get it fully torqued, that's a clue.  Zero end play would require perfect race alignment for the balls to ride in.  It must be ball-bind that's the issue.  Ouch.  They need room all the way around the track.  You might find varying end play as you rotate the flange.

It's an odd problem.  I've been surprised at how loose the rear bearings are, in general.  But that's how most rear wheel bearings are, even in live (solid) axles.  I had an old 55 Chevy truck that wore out a bearing completely, spitting the balls out, riding race to race.  You could lift the rear wheel up about 2 inches when it was on the jack.  And it just kept going until I sold it to a guy who was going to restore it.  I was a didn't-care teenager.

[Zed Head]

Last thought - a bent wheel side flange would measure out as a bent axle, relative to the wheel flange.  The bearing seating surface would be off-perpendicular to the axle bearing journals, except for two exact postilions.  Seems like the most likely cause.  Somebody slid in to a curb in the past maybe.

 

[the_unknown]

Quick Update: Just had everything arrive last night. I received two used axle stubs with companion flanges and B distance pieces so that should solve the issues. I need to blast and powdercoat one of them before I install it in the housing and I should be ready to go on Friday

[Zed Head]

6 hours ago, the_unknown said:

Quick Update: Just had everything arrive last night. I received two used axle stubs with companion flanges and B distance pieces so that should solve the issues. I need to blast and powdercoat one of them before I install it in the housing and I should be ready to go on Friday

Have you measured the distance pieces?  They get deformed.