EO2K

iTrader: (37)

There was an ongoing discussion about doing this, but I was unaware anyone actually doing it. There was a vendor who was going to offer *****, but then we all decided repacking using correct grease or replacing a damaged hub with an aftermarket hub packed with correct grease AND proper brake ducting was easier/cheaper than fancy exotic *****.

shuiend

iTrader: (24)

The exotic ***** I got were relatively cheap on eBay. At least at a price where I had zero issue ordering some.

EO2K

iTrader: (37)

I guess I don't understand the impetus for replacing the *****. Blindly replacing the ***** sounds like a solution looking for a problem. I'm not trying to be contrary or combative, I'm genuinely curious what problem you are trying to solve. Did you have a bunch of galling on the ***** and you were trying to salvage the hub?

hi_im_sean

iTrader: (3)

The hypothesis is that the grade of ***** that come with most hubs is insufficient for the job being performed. The grade includes, among other things, acceptable diameter tolerances. So if your ***** vary +/- a half thou or something, then as you may imagine, you will end up putting the entire load of that wheel on the 3 largest *****, alone. The other 10 or 12 will just be along for the ride. You've now pinpointed the load on 3 *****, that cant take it by themselves, and they spall due to contact fatique. Of the 3 bearings I killed and took apart, all 3 died from spalled *****. Spalling is direct evidence of a ball receiving to much load. So you either up grade them to tighter tolerance, or batch them into +/-, whatever the acceptable tolerance is.

And I just hate it when my ***** spall. (ill dig up some pics)

EO2K

iTrader: (37)

Makes sense. I guess its not something I've looked into as I've not experienced this failure mode.

So how many noobs are we going to get measuring bearings for concentricity with plastic harbor freight calipers?

hi_im_sean

iTrader: (3)

This is why its not done IMO. Its beyond most users.

Anyone got a CMM?

EO2K

iTrader: (37)

Exactly I mean, I own a nice Mitutoyo 0-1 .0001 grad +/-.0001 mic but its not something I would expect to find in the average Miata enthusiasts tool box.

Though I would imagine we have a rather larger percentage of users on this forum who DO own such things compared to most other Miata 'communities'

sixshooter

iTrader: (12)

So, theoretically, one could have several sets of ***** and sort them by size? Ball-matching, to coin a phrase?

shuiend

iTrader: (24)

Basically what Sean said. It was more of if I am going in to repack the bearings, I might as well throw in better ***** to be on the safe side. I think they were like $20 for 100 or something. So cheap enough that I could throw money at it and not care.

hi_im_sean

iTrader: (3)

I have multiple 0-1", tenths measuring things.



Ive had one OEM, 2 Timkens and 1 china, do this:

EO2K

iTrader: (37)

Jesus Sean, what did you do to those poor things?

Plus the $150+ tool needed for the level of accuracy required to make this worth while. Just sayin'

I personally think it comes down to duty cycle or use case. I'm not sure we need to send everyone out to buy a mic and bag o' ***** every time they repack a hub. The basic 3-4 times a year HPDE + autox or street driving guy can probably get away with a fresh hub, good grease and frequent inspection for quite some time. If you are planning on run a race series on the regular or you already own the tools then yeah, its probably worth the effort.

Of course, you could just go buy blueprinted hubs from FM @ $192/ea, sans studs https://www.flyinmiata.com/na-nb-blu...ront-hubs.html

hi_im_sean

iTrader: (3)

I just made up the number above for the example. Assuming the hypothesis is on point, im not even sure what the diameter tolerance severity is.

I have a spare hub that needs disassembled and repacked. If I ever find the time, Ill see what my starrets say about all this. Hell, maybe I can start batching ***** for people, and I can sell them in a nice little sack.

SADfab ***** Sack ©

shuiend

iTrader: (24)

I was not going to use any sort of $150 tool. I bought the same size ***** as what should be in there, but of a better spec. One day I will get to it.

Also the FM hubs are not guaranteed to be any better. Many people on here have had the same issues with those. I am pretty sure Hustler had issues with the hubs FM sells.

hi_im_sean

iTrader: (3)

How do we know the Mazda ball spec?

ball specs
http://www.thomsonlinear.com/downloa...Balls_cten.pdf
G3 or GTFO

shuiend

iTrader: (24)

These are the ***** I bought.

MetalMuffins

iTrader: (1)

The link, she don't work

hi_im_sean

iTrader: (3)

Ok, who got triggered by the word ball?

edit- back peddled....

shuiend

iTrader: (24)

******* IB ******* **** up again.

​​​​​​​100 13/32" inch Diameter Chrome Steel G10 Ball Deep Groove Radial Ball Bearings | eBay

z31maniac

We killed one in one track day sharing my car with another driver. So like 11 sessions? All proper installation info was followed and retorqued to the higer setting after getting a heat cycle on them.

My local track, Hallett, is rough and we aren't shy about liberal use of the curbs.

They did warranty the hub which was nice.

phocup

I wasn't until I saw SADfab BALL SACK. Where's my safety pin ..

So its probably reflection / ect but I'm seeing what looks to be a bunch of little weld spots on each ball ..
As for buying these off ebay .. they're cheap enough to try but what's the chances that' they're as good as / better than OEM ? Maybe there's obvious answers in the listing, but I'm a noob without $150 of tools to QC.

Have you been able to go back out with the replacement hub ? Curious as to how that held up.