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.

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.

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.

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.

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

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.

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.

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.

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?

;)

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.

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

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.

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

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.

We have never seen an ARP Miata wheel stud fail. We have a few ART studs fail so we stopped using them two years ago.

That's how I ended up with Planet-Miata rebuilt rear spindles. Nothings would get the old half-shafts out.

I'm confused.

ART states they use ARP studs (at least the ones ordered through Flyin' Miata) which is what currently resides on my track bitch.

Flyin' Miata : Chassis : Suspension components : Blueprinted front wheel hub

I apologize, I ordered my ART hubs with ARP studs. But you can order "stock" or "ARP studs" and I ordered mine with ARP.

So was it "stock" studs that broke on you?

Black ART brand extended studs, not sourced or manufactured by ARP, not OEM. Year ago.

Maybe ART no longer offers their house brand studs? I have no idea as we tossed the installed and NIB spares we had and switched to ARP's after that race.

End of this video

$104 for a set of 4. I'll change them once a year at that price.

Hmm, interesting. I just went out and checked my car, the front studs from the ART hubs that are supposed to be "ARP studs" are black and shorter. The rear studs from my Planet-Miata rebuild spindles/hubs are also supposed to be ARP, but are gold and a bit longer.

Does ARP only sell gold studs? I'm kind of unhappy if didn't actually get ARP when that's what I thought I was paying for.

ARPs are all gold plated AFAIK. The ART studs that I no longer use (I broke one last year as well) are black.

I'm trying to gather the parts for the rear hub swap in preparation of installing the TSE BBPK and need some clarification. I've already done the fronts, but have never done the rears on a Miata.

Help me with what parts I need to order to refresh the rear corners.

https://www.miataturbo.net/attachmen...ine=1369148794

33-042
33-061 (includes 33-062)
33-048
33-047

?

33-065
33-047 (or FLAPS equivalent)
reuse 33-048
remove 26-261
replace 33-062 with ARP studs
33-061
33-042

Remember that ALL new hubs are the 94-05 style, so when you're ordering ARP studs for new hubs, order them for the 94-05 rears.

I just put several sets of ARP studs in stock and I'll get them on our website in a day or two - $104 per set of 4.

Are Dorman 930-550 replacements found at Napa and such worthy of track service? I can get them for $22 a side.

Posted wrong video before. The first one was two left front studs broken in 4hr enduro, spotted at fuel stop. We elected to limp around and just take it easy on the left turns. Next day we broke all 4 LR studs. Here's that video (at the end):

That's what we have switched over to. Made in Taiwan. Radiused where the OEM's fail.

Good to know!

Is it safe to assume you are swapping out the included Dorman wheel studs with ARPs?

I would assume that to be self evident. We never use OEM studs on the race cars. Our 95R street project car has OEM studs but those will be swapped when we install the Dorman rear flanges.

From where? I am showing $44 per at Napa.

I have a Mazda hub floating around we were using for R&D. I'll try to post some photos of the Dorman part and the Mazda part together later this week.

Derp. Thanks Emilio.

Does Dorman have a solution for the front hubs that would save some coin too? Didn't see it on Rock Auto's site or NAPA for that matter.

What hubs are people getting when they order the Dorman hubs?
I ordered two hubs at once from Amazon and here is what I got.

One on the left says made in Taiwan has OEM looking studs with 1990-1993 knurl diameter and two threaded holes in the flange.

One on the right says made in China has black studs with 1994+ knurl diameter and no threaded holes in the flange.

https://www.miataturbo.net/attachmen...523_071323-jpg

Mazda's front hubs are reboxed NTNs, available for ~$100 in a few places. You can occasionally find Timkens for ~$65, and those are reboxed NTNs as well, but the Timkens may or may not have the ABS ring in the correct place and availability is spotty. I have yet to experiment with anything cheaper than the $65 Timkens.

Resale discount. Perks of running a side automotive business. :-)

Rock Auto $21.79 + $15.43 ground shipping to my location. Seems like I almost never find Rock Auto to be the cheapest overall for anything. Big orders don't usually help either because most every individual part gets its own shipping charge shipped from different locations across the country.

Contradictory Bob is contradictory

I should have an answer for you in a couple of days, because I just ordered the same thing from Amazon.

That's dissapointing, The 8 I bought from amazon two weeks ago were all the Taiwan variety. I didn't know they were for the smaller studs. Not a huge deal as the smaller knurl ARP studs still don't break.

Any chance you have a part number for the NTN and/or the Timkens?

When this is all figured out, I'm going to make a thread with all the part numbers compiled that I have. Before I do that, I need to get some verification that the below is accurate for ARP wheel studs:

ARP 100-7719 89-93 all corners, front 94-05
ARP 100-7720 rear 94-05 (and where hubs have been replaced since -94)

Amazons $32.34 with free shipping is less than Rock Auto’s $37.22 including shipping. Napaonline shows them in stock for $48.59 at the Local Napa store. If I hadn’t ridden my bike to work today I would go see what version Napa had in stock at lunch.

Experience w/Raybestos? These are $57 on Amazon Prime:

Timken: 513152 nonABS, 513155 ABS

NTN: W0133-1834777 nonABS, W0133-1599959 ABS

Correct. 7719 is all fronts and 90-93 original rears (plus some Dorman hubs), 7720 is 94-05 rears or all OEM replacement rears.

I suspect it's probably a Chinese-made version of the NTN/Timken. The ABS ring is in the wrong place as well.

The Japanese-made NTNs have green wheel studs.

Ok I just went to the local Napa. Quite an adventure actually because of the I5 bridge collapse over the Skagit river and 70,000 cars worth of daily traffic being transferred to surface streets! The hub they had was Identical to the Taiwan version of the Dorman 930-550 hub I got from Amazon but packaged in a Napa box. It uses 1990-93 studs.

Bah... I ordered parts 2 weeks too early. I've got Taiwan dorman hubs and 94+ ARP studs sitting here not doing me any good. Guess I need to order 90-93 ARPs. Anyone need a set of 94+ rear studs? (1 set = enough for both rears)

I got the same damn thing: one of each.

Ha! I did something similar. Before I realized there was a difference, I ordered 4 sets of 100-7720 (94+ rears), not realizing there were different part numbers front and rear.

You guys that ordered studs from us, send em back and I'll swap.

You can also use the f-body ARP studs in place of the 90-93s. Somehow it's significantly cheaper for 5 f-body studs than it is for 4 Miata ones.

Part number is 100-7708.

haha, related but I did the same thing with my speed6 when I had it. took me some time to find the info I needed, but I too found out the f-body studs fit the hubs.

guess I should check my hubs I have in storage due to this thread.

I'm swapping the hubs for new OEM Mazda as the current ones have been on the car ever since it rolled out of the factory.

There are no visibile signs or anything, it would be nice to get them x-rayed, but who cares.

I am having the hubs sanded down very slighly (2/100th) so you can actually slip them in and out of the bearings by hand, without destroying the bearings. I had that done a while ago so I'm not replacing bearings this time.