Replacing S30 Rear Wheel Bearings

[Captain Obvious]

Glad to help.

Before you rip everything completely apart and start over from scratch, I like your idea about moving the stub axle from the other side (that spins ok) and seeing what happens when you install that stub axle in the problematic housing. I agree that could be a good clue if the problem follows the housing, or the stub axle.

In any event, I hope you get to the bottom of it.   

[the_unknown]

I've got new wheel bearings coming in tomorrow so that should help rule out a faulty new bearing. I will also get a chance to try the other axle stub then too. 

My buddy did some measuring on the new t3 housing. Keep in mind these are the fabricated ones and not the converted ones from people sending in their cores. According to his measurements, the space between the seating surfaces is longer than the B housing / the stock unit.  The bearing bores are slightly smaller than the stock unit as well and are a little more out of round. When he says small, I'm assuming a thousandth or two.

I'm starting to think that the new housings were warped from the heat during welding and are slightly warped in one way or another.  The seating surfaces could look like this _/-----\_ or like _\------/_ instead of _|------|_ if that makes sense. Sorry for the crappy ASCII art.

 

[Captain Obvious]

25 minutes ago, the_unknown said:

According to his measurements, the space between the seating surfaces is longer than the B housing / the stock unit.  The bearing bores are slightly smaller than the stock unit as well and are a little more out of round. When he says small, I'm assuming a thousandth or two.

I'm starting to think that the new housings were warped from the heat during welding and are slightly warped in one way or another.  The seating surfaces could look like this _/-----\_ or like _\------/_ instead of _|------|_ if that makes sense. Sorry for the crappy ASCII art.

I understand the ASCII art perfectly. And if the seating surfaces are not square to eachother, there will be big problems.

There will unquestionably be dimensional changes caused by the welding operations and my expectation would be that T3 would have started with raw materials and designed the housings such that after welding, there would be extra material that would have to be machined off to square up the surfaces and make them precise. Above, you mentioned looking for a thousandth or two, but when it comes to bearing placement, you're actually looking for the tenths of thousandths. A thousandth or two is usually way way way too much. In fact, a thousandth or two would make the difference between 200T required to press a bearing in vs. one that drops in free with just it's own weight.

If those bearing bores are out of round and/or not coplanar to within a fraction of a thousandth, then I think you ought to put in a call to T3.    

[the_unknown]

2 minutes ago, Captain Obvious said:

I understand the ASCII art perfectly. And if the seating surfaces are not square to eachother, there will be big problems.

There will unquestionably be dimensional changes caused by the welding operations and my expectation would be that T3 would have started with raw materials and designed the housings such that after welding, there would be extra material that would have to be machined off to square up the surfaces and make them precise. Above, you mentioned looking for a thousandth or two, but when it comes to bearing placement, you're actually looking for the tenths of thousandths. A thousandth or two is usually way way way too much. In fact, a thousandth or two would make the difference between 200T required to press a bearing in vs. one that drops in free with just it's own weight.

If those bearing bores are out of round and/or not coplanar to within a fraction of a thousandth, then I think you ought to put in a call to T3.    

I have a feeling that's what I'm going to spend most of my day doing (talking with T3). I can't seem to find anyone else that has used their setup either to see if I am the first person to run into this issue. I forgot to mention that before tightening down the companion flange, he measured runout at 0.001 of the stub shaft.

[Captain Obvious]

1 minute ago, the_unknown said:

before tightening down the companion flange, he measured runout at 0.001 of the stub shaft.

Yeah, that's not cool. If that shaft is straight, there's no way you should be seeing that. Maybe out at the edge of a big rotor or something, but no way you should be seeing that at the axle without the mechanical amplification of big disk.

Are you seeing that on both axles? One of them turned out OK, right?

[the_unknown]

I think he is seeing it on one axle but I will confirm tomorrow. I just reread some of my texts with him and he said it was less than a thousandth of run out. He seemed pretty confident it wasn't a bent stub shaft. 

I haven't been impressed with T3's product so far. They look pretty but I've had multiple other issues with these coilovers.

 

[Zed Head]

4 hours ago, the_unknown said:

My buddy did some measuring on the new t3 housing. Keep in mind these are the fabricated ones and not the converted ones from people sending in their cores. According to his measurements, the space between the seating surfaces is longer than the B housing / the stock unit.  The bearing bores are slightly smaller than the stock unit as well and are a little more out of round. When he says small, I'm assuming a thousandth or two.

Do you have any closeup pictures of the bearing mounting area?  It would be interesting see.  That's a fairly complex area to fabricate to those tolerances, from scratch.  Matching two bores in concentricity, parallelality, along with dimensions.  I made the second word up myself.  I didn't know anybody was trying to match the Nissan product there.  That would take some skills.

[the_unknown]

8 minutes ago, Zed Head said:

Do you have any closeup pictures of the bearing mounting area?  It would be interesting see.  That's a fairly complex area to fabricate to those tolerances, from scratch.  Matching two bores in concentricity, parallelality, along with dimensions.  I made the second word up myself.  I didn't know anybody was trying to match the Nissan product there.  That would take some skills.

https://technotoytuning.com/nissan/240z/evolved-rear-coilover-conversion-datsun-240z

 

Those are the ones I purchased. I don't have any closer up photos yet and I won't until tomorrow. One of the biggest things I noticed right off the bat is that there is no grease storage cavity where the distance piece goes like the stock housing has. Not sure if it would matter or not. 

[Zed Head]

So it's just a boring and honing operation, probably.  Should have left the final sizing for after it was all welded together.

You might see some scrape marks in the bore, showing where the fitment problems are.  A bright light and a camera could help.

[the_unknown]

1 minute ago, Zed Head said:

So it's just a boring and honing operation, probably.  Should have left the final sizing for after it was all welded together.

You might see some scrape marks in the bore, showing where the fitment problems are.  A bright light and a camera could help.

I'll definitely be taking a bunch of photos and carefully inspecting and measuring everything tomorrow assuming the other stub axle binds as well. 

 

I will need to do a long write up regarding their QC on here and maybe Hybrid Z as well. I documented a lot of what I've done on a thread in the Off Topic section of a Subaru forum but this would be good to put in Z focused forums as well. I've been working on doing fronts and rears since January now and I'm still not close to being done now. 

[the_unknown]

So I swapped the other stub shaft in and it fit just fine. We also put the suspect one into the other housing and it was binding in that housing too which means it's an issue with the shaft or outer bearing. 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. I've got a set of two new used ones on order from ebay that should be here next week. Hoping that fixes it and I can enjoy some of this nice spring weather soon.

[Captain Obvious]

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.

On ‎8‎/‎16‎/‎2018 at 2:42 AM, Jason240z said:

Hi

 

yes tried without the seal.... checked the hubs too,  measured bearings against the lip they sit on, then the height of the hub.  Fully home...

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?