When was the last time you changed your rear hubs?
 

OEM hub, pulled out of a junkyard ~2 years ago. Never seen duty on a forced induction or V8-powered car, just a 140whp HPDE/sprint/enduro car. How old are your hubs? :party:

Oh lord. That could have gotten really bad, really quick. Can not believe it didnt roll.

Keith can relate - just last weekend... :crx:


Were there any early signs of this that you may have caught in hindsight? Lucky it stayed upright and nobody was close enough to T bone you as you came around. :party:

In light of recent events I proclaim May to be National Hub Awareness Month.

The official color for this campaign will be skid-mark brown in honor of Andrew and Keith's tighty whiteys which succumbed to this tragic and entirely preventable condition.

Any pictures of the broken hub? Your slowmo video shows what looks to be a brake rotor passing you.

Wow! This just happened to me yesterday - turn 17 at Sebring. I'll post the video soon.

What can we check / inspect to prevent this from happening?

Attachment 75817

Attachment 75818

Hrm, I thought recently about ordering some rear hubs when I was ordering front hubs, but I thought "meh, only really seen one failure..." Starting to rethink that. Mine have at least 150-200 track days on them, 92K miles, or however you want to look at it.

Do you have a picture of what failed?

robert

Pics here.

Definitely a brake rotor.

https://www.miataturbo.net/attachmen...ine=1367849050

You folks with failures: any idea how many days/hours/miles were on your hubs? Were you running street tires, NT01s, A6s, or what?

robert

Good to see that you're ok. I checked my rear hubs after I lost a wheel at Laguna Seca. :( I had V8R aftermarket hubs, though. Not sure if Keith had the same aftermarket hubs as I did or the factory ones. The one that didn't fail has a nasty hair-line crack running all the way around the base on both sides:

Big pics with obvious cracks. The second one shows several radial cracks, too.
http://farm9.staticflickr.com/8039/8...38082cc7_o.jpg
http://farm9.staticflickr.com/8040/8...9f4c1778_o.jpg

The hub on my car had 22k street miles and 12k track miles on it when it failed. The hub was originally installed on a 2000 SE, and swapped into my 1993 NA as part of a complete rear sub-frame assembly.
My car makes 185rwhp and I mostly use Hoosier 225/45/15 R6 or A6 tires. Hoosier 205/50/15 R6 tires were on the car at the time of failure.

Good grief. I guess I might as well add rear hubs to the shopping list for when I do the brake upgrade.

I missed that the second video was Tanner's. Taken from his blog:
"It turns out that this was a known problem with the V8Roadsters hubs, which led to a redesign several years ago."

Hmm.. So a nonstandard hub?

I actually changed my rear bearings this weekend. Ive never seen a rear fail, but I figured for $20 dollarbucks per side, why not? Looks like that was a good decision based on the bearings that came out.

Now Im wondering if I shouldnt have stuck a new hub in there while I was there.

Any failed hubs from cars that didn't run anything stickier than RA1's?

Wow!
I know guys with "other" cars talk about driving the wheels off it, but
You guys actually do it!

So it looks like failure is not just with the v8r hubs but also some stock hubs.
I know there were some companies that were "broaching" hubs for the v8 conversion axles to fit.
I'm assuming v8r does not build their hubs this way?

At first I've never heard of this occurring on miatae, now everyone and their mother are killing hubs?

Three different hubs being discussed here:

1. OEM. Three known failures (myself, CoralDoc, and a Socal SM guy with a ton of hours on his car)
2. V8R 3/8" (old). Two known failures, possibly three. Keith and Mike, and potentially a third (not sure if he broke an old V8R hub or a rebroached OEM hub).
3. V8R 1/2", no known failures

I didn't get any pics of mine, but I still have the spindle and axle. My failure looks identical to CoralDoc's, all the way down to the crack pattern in the brake rotor.

I'll still use OEM hubs, but they'll be brand new from Mazda and I'll change them once a year.

You should have.

It's the hubs that are failing, not the bearings.


So what are people buying that aren't failing? New "redesigned" v8r hubs?

Read the thread an posted before i refreshed to see the one above me.

Edit2*
This is somewhat common, and has happened before on stock hubs, on spec miatas. Here is one for example. Pictures inside:
XceedSpeed

Dam Keith asked me if I ever had an issue wondering if it was a high hp issue and I haven’t. Maybe time to put some new rear hubs on.

Bob

OEM part number for those looking for it: B01A-33-060

Correct. My hubs looked to be in good shape (I did examine them when they were out). I cant recall hearing anyone have a rear bearing failure either, but after seeing the condition of mine when they came out, I cant believe they hadnt failed.

Not to take away from the discussion of OEM hubs, but (2) has 6+ known failures if you count people outside of CA. IMHO, they are pretty much guaranteed to break in just a few track days.

For those considering aftermarket - OEM works and has far more testing than other pieces. I wouldn't jump to aftermarket unless your axle requires it.

Andrew, holy crap dude, your hub couldn't have picked a much scarier place to let go than T8 of Big Willow. That was rough just watching it. For a second there it looked like you were going shiny side down. Really glad to see that you're ok, and the car is relatively undamaged.

I was speaking with Barry Hartzel (well known CA Spec Miata builder/racer) a few years ago about prepping a car for the track and he mentioned rear hubs specifically as a common failure point for early miatas - sounds like there are probably way more OEM rear hub failures than what you've got on that list Andrew, and all of those on lower powered miatas. I can't remember perfectly now, but I believe Barry said that the early hubs were either cast in a different manner, or made with a different composition of metal that made them weaker than later model rear hubs. Either way though, they can all fail with enough use.
-Ryan

I wonder if this is why the 1.6 hubs were phased out?

Interesting looking at Mazdacomp parts under 2004 miata

Rear hubs are $91.18 each

But they list two different bearings.
B455-33-047D BEARING $46.63
And
B455-33-047D-MV TAPER BEARING $27.37

What’s the difference? And why would they list two different options. Every Miata rear bearing I have seen has been ball type not a tapered roller. I have not had good luck with tapered rollers on any other cars.

Barry told me the 5 speed trannys were just as strong as the 6 speeds as well. I got a chuckle out of that statement. But it wouldnt suprize me if the hubs got stronger at some point during production. I forget when they changed the stud hole daimeters. FWIW Im still using the small studs front and rear.

Bob

Interesting. Mazda lists one part number for 90-93 (B455-33-061) and one for 94-05 (B01A-33-060). Both parts are superceeded by B01A-33-060A. So Mazda made an upgrade, but the upgraded parts still fail with enough use.

edit: lol @ "5-speeds are just as strong as 6-speeds". That's some Spec Miata Wisdom(TM) right there. :hustler:

Glad to see your OK and the car is easily fixable. Thanks for the warning and info. You scared me appropriately into getting ready to order my rear hubs new.

I never want to drive another car again after watching those.

Emilio pointed me here.

I saw heat damage/stress on rear flange of my '99 NB. It made the drive from SOCAL to NC when we moved out here last summer. I had a local shop do the hub last summer and they warned me they had been seeing this failure. They replaced the parts and showed me the old one. They also checked the other side and told me it had been replaced by someone else (previous owner). This was a mostly stock NB the previous owner used for autocross around San Diego. It is also my wife's daily driver.

My car did indeed have the old 3/8" V8R parts. It was the first track day I'd done on them, as I'd just borrowed them from one of the other FM cars due to some QC problems with the parts I was planning to use. Their history before that includes a fair number of track days on typical 225 NT-01s, but not driven all that hard. I was running a set of 225 RA1s in the video. Before that, I had OE hubs.

Here's my broken V8R 3/8" beside the current 1/2" design. It's my understanding that Dean Thomas' broken hub was also one of these 3/8" units. Anyone with older V8R hubs, please check to see what you have. I would strongly recommend the 3/8" ones go in the dumpster ASAP.

There's more to the new ones than just material, Shandelle at V8R says that the inner and outer radii were moved apart (axially, I assume) by 1/4" to create a better load path. Interestingly, Mazda OE hubs come in at 9mm, so they're thinner and stronger than the original V8R part.

https://www.miataturbo.net/attachmen...ine=1367862926

Shandelle states he's broken two stock hubs in 12 years of racing Miatas. He says it always starts with cracks on the back side. There are currently 5 cars which are seeing 10-15 events a year on the new V8R hubs, not "babying around and giggling" in his words. Not as big a pool as I'd like to see, but the theory is good.

After my failure, I was having trouble deciding if I wanted to go to the 1/2" V8R or go to new Mazda pieces. Andrew's convinced me, I'm going to go to the beefier V8R.

The upgrade may not be in the hub design itself, but you probably know they went to a larger spline on the studs in 1994 and that certainly would have generated a new part number. Not sure what the 060A part is.

Sounds as though the every season replacement schedule is common with high end SMers.

I know we rib on them but there is a wealth of knowledge in the SM community that isn't shared as publicly.

:giggle:

I see the same thing but B01A-33-061 appears to be the hub without studs for the same price. Is B01A-33-060 a complete assembly with the bearings already installed? Early in the thread Andrew said the inner seals were a PITA and mentioned a ballpark price with new ARP studs at around $100 (assuming MMD pricing).

Wow. Glad to see you're okay. That could've been way worse...

Just one more thing to add to the list of "regular maitenance" items on a track car

Recall our discussion 2 weeks ago (more like rambling on my behalf) about when to replace rear hubs? Face it Andrew - I'm bad Karma and will have to stop doing business with you for your safety. Glad you came out of that relatively unscathed :party:

The -MV part is the same form factor as the other one but of lower quality, thus the lower price. MV stands for Mazda Value quality. The other one is OEM quality. This is not just for the bearings but for any parts from the Mazda catalog. Guess what many shops use to fix unsuspecting people's cars ... lol

Speaking of bearings, is it possible old bearings have any effects on those hub failures related to high temperature or vibration?

I'm stunned watching those videos and am sincerely glad everyone is alright.
I can't believe these failures didn't result in a roll.

Mazdaspeed sent me a B01A-33-060A a couple weeks ago (screwup, they were supposed to send me a *front* hub), which is the supercession replacement part from a -060. I have it sitting in front of me -- it's a splined hub casting with standard studs pressed into it, no bearings, no seals, no ABS rings.

--Ian

So this is only an issue with R-comp tires (or sticky 225s on 15x9s) and lots of track time correct ? Was hoping to get my car setup to do HPDEs in the future now Im a little scared lol

Yikes....I will listen to the warnings and change mine before the next event. Gotta get these on a maintenance cycle like the fronts.

I don't think there's any real consensus of what is and is not an issue for it, aside from V8 cars running the old-design V8R hubs being a bad idea.

More torque means more load, more grip means more load, and bouncing it off berms at the track means shock loads. Any of those is going to mean a greater chance of failure, but how much is too much? No idea.

Anecdotally, I ran 40-50 track days on the original rear hubs on my 99, with R compounds (V700 Victoracers and RA-1s). I swapped them recently as a part of a (currently incomplete) ABS retrofit project so they're sitting on the workbench -- I plan to look at them closely.

The solution is to do what real race teams do. You pick a defined lifetime period for the part and then track when it was installed and how many miles/hours/track days/whatever it has on it. When it hits that lifetime, you replace it and throw the old one in the trash, no matter what it looks like.

--Ian

Thanks for sharing details.
Note that ABS rings are on the half shafts.

To roll the car needs to 'hook'. Without a wheel there is less to hook onto?

I was thinking the sharp metal bits would dig into the ground once off the pavement. I've seen vehicles roll going a lot slower than Sav was going. I didn't think he would ever stop spinning.

My hub failure is now up on YouTube.

Be sure to watch the rear-view mirror after the car comes to a stop :).

:36 creepy but..lol

miss me?!

Btw saw a post elsewhere mentioning Andrew's hub failure during the weekend at Willow Springs. The same post also mentioned another Miata catching fire and a picture linked of it. What the hell happened with that one:

https://www.miataturbo.net/attachmen...ine=1367948767

What does anyone think a reasonable replacement schedule is? Every season?

Maybe two seasons on an HPDE car?

That is the big question. I've got about 20K miles on my car since 10/2010 in 107 days on track (where a day is usually four 20-25 minute sessions), and it was a track car before I bought it; should I be concerned or not? On the plus side, I'm only running NT01s, no Hoosiers, and my power level is low.

Is this something that we can inspect with the hub on the car?

robert

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)

You can inspect it, but that doesn't mean a crack won't start the next time you drive it. With as many hours as you have on your car, I'd change them.

That works out to about 90 track days for me. Our local track is 5 20 minute sessions a day, unless it's a different organizer than the track itself.

I bought rebuilt spindles, with fresh hubs/bearings/ARP studs, and they have 4 days on them now. Good to know I *shouldn't* have to worry about it for awhile.

I blame the track on the sebring video, not the miata's hub. I hate that turn in any and all video games I play it on, looks like they're not that far off in harshness. Glad you're ok.

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.

Andrew, I did not realize the extent of your track whore-mongering, sounds to me like you should replace every six months :-)

Every 2 years? That's 9000 runs(or 500 3 person, 3 run weekends). I'm now thinking of changing mine from the OE ones on the car, but then I dont' think I'll touch them for a very long time.