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-   -   When was the last time you changed your rear hubs? (https://www.miataturbo.net/race-prep-75/when-last-time-you-changed-your-rear-hubs-72613/)

k24madness 05-07-2013 10:50 PM


Originally Posted by Ski_Lover (Post 1009651)
A respected race car builder / shop owner here in the bay area told me the original hubs that came on the Miata seem to live significantly longer than the OEM replacements. He recommended I replace mine every two years and also said regular racers should do it every year.

That sounds like he is talking about the fronts. I like used fronts over new because the bearings are rounder from all the miles of polishing. The grade rating of new ball bearings is poor. Over time they end up rounding themselves out.

The rears would be better new if the metallurgy was know to be of the same or better quality from 20 years ago. That is debatable to.

Phone 05-07-2013 11:42 PM

Is it worth it to repack the fronts if you're going to replace them every 150 hours?

I'm just thinking of what sort of schedule I should use for "wear" items.

mr_hyde 05-08-2013 12:38 AM

The failures being discussed are structural failures on the rears. Generally the fronts are replaced much more often for bearing failures/maintenance so the hubs themselves have cooked races and are tossed before they have a chance to break.

JasonC SBB 05-08-2013 01:47 AM

Are there known failures in cars that don't run stickier-than-RA1 rubber?

Savington 05-08-2013 04:25 AM


Originally Posted by JasonC SBB (Post 1009764)
Are there known failures in cars that don't run stickier-than-RA1 rubber?

I wouldn't consider "I use street tires" a reasonable excuse to avoid swapping these - the parts are too cheap and the failure mode too catastrophic. In addition to the hub, I lost a wheel, three tires (flatspotted the fronts), an exhaust system, and wrecked the rear bearing, and I got extremely lucky.

hustler 05-08-2013 09:46 AM

Since we're on the subject, how often do you guys replace ball joints? My front uppers have like 250 hours on them. lol

Phone 05-08-2013 09:51 AM


Originally Posted by mr_hyde (Post 1009744)
The failures being discussed are structural failures on the rears. Generally the fronts are replaced much more often for bearing failures/maintenance so the hubs themselves have cooked races and are tossed before they have a chance to break.

Yeah, I know; however, I was asking how many hours do people usually get on the fronts if they repack them versus if they don't.

I am trying to do a Cost/Benefit of buying front hubs, replacing the ball bearings with better spec'd ones, and repacking with AMSoil or just replacing with Timken branded hubs straight from the box whenever I do the rear hubs.

Sokool 05-08-2013 10:52 AM

Great now every time I go around turn 17 at Sebring I'm going to be thinking about my hub failing. Lucky it didn't happen earlier in the corner and you ended up in the wall.

Ski_Lover 05-08-2013 11:41 AM


Originally Posted by Savington (Post 1009778)
I wouldn't consider "I use street tires" a reasonable excuse to avoid swapping these - the parts are too cheap and the failure mode too catastrophic. In addition to the hub, I lost a wheel, three tires (flatspotted the fronts), an exhaust system, and wrecked the rear bearing, and I got extremely lucky.

Few issues rival this one (like loosing a tie rod). This is Life (or car wad) insurance we're talking about. Time to replace the hubs on our 97 street/STR Miata.

psreynol 05-11-2013 10:20 AM

wow that was a good one. doing that in the wrong spot could easily mean a totaled car, or worse

quick list of damaged/ destroyed parts?

Handy Man 05-11-2013 10:24 AM


Originally Posted by Savington (Post 1009778)
In addition to the hub, I lost a wheel, three tires (flatspotted the fronts), an exhaust system, and wrecked the rear bearing, and I got extremely lucky.

;)

Scrappy Jack 05-14-2013 06:38 AM

1 Attachment(s)
https://www.miataturbo.net/attachmen...ine=1368527896

CoralDoc 05-14-2013 07:16 AM


Originally Posted by Savington (Post 1009596)
Every ~150 track hours is a safe estimate. You could probably safely push that to 200 hours, but the failure mode is so catastrophic that it's not worth the risk. ~150 hours is about one year of racing for me. (25-30 events a year, 5-6 hours a weekend)

I just did a little math. My hub failed after 6k track miles (+36k street miles that really don't count), and at only 60mph, that's only 100 track hours!
Food for thought.

Mobius 05-14-2013 09:54 PM

How old was the hub when tracking started? Mileage/calendar age.

CoralDoc 05-14-2013 10:09 PM


Originally Posted by Mobius (Post 1011715)
How old was the hub when tracking started? Mileage/calendar age.

The hub was 9 years old and had 22k street miles on it when I installed it in my car as part of a complete rear end swap (rear subframe, diff, A-arms, axles, etc. It came from a 2000 SE. However, I don't think street miles produce anything like the stress the hub experienced on the track

thenuge26 05-15-2013 09:55 AM

You guys are not making me feel better about the rusty old hubs that are stuck on the rear axles I got as part of a torsen swap. Any tricks to getting them off so I can check them out? You know besides running them on track until they fail...

z31maniac 05-15-2013 10:21 AM


Originally Posted by thenuge26 (Post 1011818)
You guys are not making me feel better about the rusty old hubs that are stuck on the rear axles I got as part of a torsen swap. Any tricks to getting them off so I can check them out? You know besides running them on track until they fail...

I ran into that problem when changing all bushings and stuff on my '90. I ended up just buying rebuilt spindles from Planet Miata that come with new hubs, ARP studs, etc. Think it's $400 for the pair.

Savington 05-18-2013 02:39 PM

Big impact gun + 10-ton press will get the axles out. Press the old bearing out, press a new one in, press a new hub with new studs into that.

codrus 05-18-2013 03:57 PM


Originally Posted by Savington (Post 1012957)
Big impact gun + 10-ton press will get the axles out. Press the old bearing out, press a new one in, press a new hub with new studs into that.

Any thoughts on the useful lifetime of ARP wheel studs?

--Ian

Morshu 05-18-2013 09:01 PM


Originally Posted by thenuge26 (Post 1011818)
You guys are not making me feel better about the rusty old hubs that are stuck on the rear axles I got as part of a torsen swap. Any tricks to getting them off so I can check them out? You know besides running them on track until they fail...

My axle was stuck in my hub, and even after applying pb blaster daily for a week and a half, and taking it to 3 different shops that used their 20 ton presses on it, it still wouldn't budge. I had to buy a new knuckle/hub from a wrecked miata to complete my torsen swap.

You can try to separate them, but my advice would be to just buy another axle and knuckle, and a new hub and wheel bearing. Don't forget anti-seize on the axle splines.


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