Replacing S30 Rear Wheel Bearings

[the_unknown]

1 hour ago, Captain Obvious said:

Well that's pretty definitive about the stub shaft. Hopefully the replacements from ebay will solve the problem! That would be a really easy solution. A lot easier than pulling everything back apart and starting completely over. Unless you have a neat way of pulling the outboard bearing off the stub shaft without putting pressure on the balls, you might consider using yet another new outboard bearing on the new replacement ebay stub. Depends on how you feel about reusing the one you already pressed on.

Already ahead of ya, I ordered new timken bearings on and plan on discarding the old ones or keeping them as backups. Both inner and outer have seen some abuse by being pressed in and out a few times so i'd rather just be safe and do it right instead of doing it twice. Thanks again for all the insight.

[Zed Head]

 

15 hours ago, the_unknown said:

We used feeler gauges to check under the outer bearing collar and the gap was the same all the way around which leads me to believe its an issue with the stub shaft. 

Do you have any way to measure runout?  Should be there.  Sounds like you removed the shaft and the installed bearing.  Could be a damaged bearing.

There's also tolerancing.  If T3's bores are on the small side and you got a "big" bearing race, maybe it's still a fit issue.

Sounds like you'll get it fixed, just not clear, exactly, what the problem is.

[Captain Obvious]

10 hours ago, the_unknown said:

Already ahead of ya, I ordered new timken bearings on and plan on discarding the old ones or keeping them as backups.

Cool. It's money, but those bearings aren't the kind of thing you want to do any more times than necessary. Glad to help and good luck with the rest of it. Keep us posted as to how it all turns out.

8 hours ago, Zed Head said:

Do you have any way to measure runout?  Should be there. 

I'm having a hard time picturing a good way to measure things to look for problems (like a bend) with a stub axle. You need good reference points and I'm not sure what you would use and how you would fixture it. The only precision surfaces on the axle are the bearing journals, but how would you detect a minute bend in the shaft between the two?

What you're really looking for is that the two bearing journal circles are not on the same axis center anymore. How would you fixture to detect that?

[Zed Head]

True.  A lathe might be the way to do it.  Set it up so that one journal is centered and the other should be too.

Maybe a flat surface with the axle journals on it and a bright light under the contact points, or some very fine feeler gauges.  But the dilemma here is the axles could be fine, but the seating of the inner race is not.  Just looking for confirmation.

Since he has new bearings coming, he might as well pull the ones he has and reseat them.  Maybe swap bearings on the axles in question and see if the problem follows the axle or the bearing, or neither.  Maybe one of the bearings has a bent ball retainer, for example.  Once the two races get aligned the retainer locks up?  Or the inner race itself is defective.  Could be cracked.  Just guessing.  A bearing swap might tell something. 

 

[Captain Obvious]

I considered something like the lathe, but the problem is that even though you can chuck something up and adjust it to be perfectly centered (within the limits of your measuring equipment), that centering is still only at one point along it's length. The jaws are never good enough that you can assume the shaft sticking out of the chuck is perfectly normal to the chuck jaws.

The optical method you described crossed my mind as well, but I don't know if the gap would be large enough to see. I've got a granite block designed for such things, but don't know if I would be able to see a quarter thousandth gap even with a strong light. And a quarter thousandth off from center at the journal could translate to more than that at the edge of the outer bearing race.

Back when they made the stub shaft, they turned it "between centers" (That's the two little holes in the ends.) To produce the shaft, they mounted the raw stock between two points that were located in those holes. But the problem now is that those holes are all rusty and worn and I doubt you can trust the accuracy anymore to the level required to check the journals for runout. But if you could, that's probably the right way to do it. Fixture the whole thing up on the granite block... Mount the stub between centers and indicate each journal.

I'm not a machinist and I'm sure someone working in a metrology lab would be able to do this in a snap.

[Jason240z]

On 4/24/2019 at 2:54 PM, Captain Obvious said:

Well that's pretty definitive about the stub shaft. Hopefully the replacements from ebay will solve the problem! That would be a really easy solution. A lot easier than pulling everything back apart and starting completely over. Unless you have a neat way of pulling the outboard bearing off the stub shaft without putting pressure on the balls, you might consider using yet another new outboard bearing on the new replacement ebay stub. Depends on how you feel about reusing the one you already pressed on.

And all this talk about wheel bearings and the resurrection of this thread reminds me... We never heard back from @Jason240z about the final outcome with his car. I believe his car is back on the road (so his issues have been resolved), but I don't think the loop was ever closed about what the problem was. Hopefully he can fill us in?

Hi Mr CO.

Its 10000000000% not on the road. ?

However did make a some shims that 'fixed the issue, I might check the new bearings size against the old though(annoyed I didn't think of that before).

Stub axles are run true in the bearings, its just that they bind when torqued up.  Reading the above, it seems the new Timken bearings could be the issue?  I might make a new distance piece for the centre of the hub and then its a single shim for the outside......

Bloody annoying really.

[the_unknown]

We tried using his metal lathe to test run out and used the housing with axle and the measured the runout against the hub. It was over a thousandth at that point but still difficult to tell. I should have the stubs in next week and plan to toss new bearings into it just to try and eliminate that possibility. 

So far, the only thing we have ruled out is a housing issue. It could still be a bent stub shaft, bearing, or distance piece issue (I ordered those most liekly culprit to least likely culprit. I forgot we re used the stock distance piece but I doubt it is that as none of the sizes that we machined and tried made a difference on the first housing. I'm more curious than annoyed now as to what the hell it could be. I hope it isn't a bearing issue, I thought timken made some of the best bearings for these cars.

 

[Patcon]

Timken has an excellent reputation. It would be disappointing if they were the issue

[Zed Head]

Manufacturing companies are always trying to cut costs.  It's in their DNA, it's actually part of the deal of being a public company, maximizing shareholder value.  Sometimes they go too far.  You never know.

https://www.nytimes.com/topic/company/timken-company

https://www.google.com/search?biw=1496&bih=723&tbm=fin&ei=yRXCXK_sHtnN0PEPhaKo4A0&q=NYSE%3A+TKR+&oq=NYSE%3A+TKR+&gs_l=finance-immersive.3..81i8k1.3013.3013.0.3293.1.1.0.0.0.0.55.55.1.1.0....0...1c.1.64.finance-immersive..0.1.55....0.DgBSm6n_rFc#scso=_zRXCXOziLoK-0PEPw6WEuA82:0

[Captain Obvious]

20 hours ago, Jason240z said:

Hi Mr CO.

Its 10000000000% not on the road. ?

Jason,  Oh! Sorry! I must have gotten my wires crossed... I thought you were on the road already.

It's easy for me to rule stuff out from the comfort of my chair, but I really doubt that it's an issue with the new bearings.

So I think that if you're still chasing this issue, you really need to figure out a way to stick something down inside the hub and take a direct measurement on the distance between the two bearing mounting surfaces and see if that number lines up with the length of the distance pieces. Sacrifice a pair of cheap calipers like I did or something.

[Captain Obvious]

18 hours ago, the_unknown said:

We tried using his metal lathe to test run out and used the housing with axle and the measured the runout against the hub. It was over a thousandth at that point but still difficult to tell.

I think the best way to look for runout would be to put the whole thing together as intended and then indicate (mag mount on the strut tube or something) off the hub. Maybe check both along the drum mounting surface for runout in the longitudinal direction, and also along the four rounded sections of the outer perimeter of the squared off hub for runout in the axial direction. Of course, this is all assuming the old rusted hubs are clean enough to even get reliable measurements.

Did you make double dog sure that the distance pieces were square ended? Some of the distance pieces that have crossed my bench had been modified by previous handlers and were ground on one or more of the ends chasing a problem. Not only were they too short, but they weren't square on the ends anymore.

[the_unknown]

3 hours ago, Captain Obvious said:

I think the best way to look for runout would be to put the whole thing together as intended and then indicate (mag mount on the strut tube or something) off the hub. Maybe check both along the drum mounting surface for runout in the longitudinal direction, and also along the four rounded sections of the outer perimeter of the squared off hub for runout in the axial direction. Of course, this is all assuming the old rusted hubs are clean enough to even get reliable measurements.

Did you make double dog sure that the distance pieces were square ended? Some of the distance pieces that have crossed my bench had been modified by previous handlers and were ground on one or more of the ends chasing a problem. Not only were they too short, but they weren't square on the ends anymore.

He's been teaching me to run his lathe so I may give this a shot as practice for measuring the runout. Just not sure how accurate the initial tooling holes. The hubs aren't in terrible shape but they aren't perfect either and I'm not sure I can get an accurate reading based on the surface rust on the hubs.

 

The stock distance piece was fairly square and pieces we turned were square down to .00001. Neither made a difference in the binding. I haven't ruled it out yet but it's low on the list. New stubs should be here tuesday and I'll post a (hopefully happy) update then.

21 hours ago, Patcon said:

Timken has an excellent reputation. It would be disappointing if they were the issue

That's what I've always heard and never had an issue with their bearings. I'd be surprised if that was the culprit.

 

Edited April 26, 2019 by the_unknown