45 replies to this topic

[Ken Nesbit]

I have a question about the front hubs/bearings and what makes them wear out so quickly. I run an FP miata and just trying to guage how closely I need to watch them. Is the general feeling that the wear is due to the amount of camber you have to run in SM or just the rigors of racing in general? I run between 1 and 1 1/4 negative camber so it's not excessive compared to what I hear the SM's run, but wanted to get other opinions....thanks in advance..ken

[davew]

I see a couple causes.

1- We just plain abuse the $#!t out of them
2- Too much wheel offset puts even more stress on the bearing
3- lack of sufficent quantity and quality of grease as installed from the factory
4- Excessive heat when used in the rain, causes condensation inside the bearing. Then a rust pit and then failure. Especially if seals have been damaged during repacking

So what can we do

1- Nothing
2- nothing
3- repack with synthetic grease on a regular basis.
4- repack the wheel bearing after any rain race. Even one session. Replace the seals when needed

Dave

[dmathias]

Oooo, oooo, I have a theory. Because they're CRAP!

You can drive a 1960s-70s GM product 20 times around the Earth without repacking the wheel bearings. This Miata crap if you sneeze at them wrong they're toast. Some little enterprizer needs to machine the hubs to accept 1973 Chevy Nova bearings and races. End of problem. Roller bearings, not little f'n balls.

That said, I've had pretty good results from East Street hubs. (no financial interest - unless of course Jim wants to slip a couple $$ my way).

Edit: How the Hell are you s'pose to replace the seals - has anyone EVER found a source?

[davew]

I have replacement seals for Mazda factory hubs in stock

[dmathias]

Why am I just finding this out?

[davew]

Aren't you on my email list? I put them on there about 6 weeks ago.

Available on my website.

Dave

[Tom Hampton]

Yeah, I guess some of those will be on my next order. I was bleeding the brakes Sunday, and noticed some redline inside on the front dust covers.

-tch

[dtfastbear]

+1 on repacking. I've posted it several times before that I'm a firm believer that Swepco 101 is THE grease to use - for performance and longevity.

That being said, I have a rotation of 7 hubs across two miata race cars that I swap out and rebuild after 2-3 race weekends, depending on how much track time and who's driving. Once you know the couple little tricks to rebuilding them, it only takes about 20-30 minutes each. Keep cleaning and repacking them and they'll last a long time. If you wait until you can feel movement in the bearing, you're WAY too late and the hub is junk. But, even once you junk a hub, I'd recommend keeping the plastic bearing keepers as spares, as it is easy to crack those things when rebuilding a good hub.

Cheers,

Dean

[FTodaro]

How often do you need to repack the rear's

[Bench Racer]

I didn't know when the OEM's started doing this hub machined outer wheel bearing race so I questioned a mechanic friend. According to him it started with front wheel drive cars in the late seventies/ealry eighties. The OEM economics spread from there. This is kind of similar to the front wheel hubs breaking on the production RX7 race cars.

[Matt McBride]

Huh- I'm getting about 3 years on factory hubs. Between racing 4-5 times a year, and an equal number of driving schools (sharing the car b/w 2 people), you'd think we beat them up quicker than that. I can't even remember when the last time I replaced a front wheel bearing/ hub was...

That said, they'll probably both go kaboom next race.

[Sphinx]

+1 on repacking. I've posted it several times before that I'm a firm believer that Swepco 101 is THE grease to use - for performance and longevity.

where do you buy it from? A local circle track race shop near my house stopped stocking redline and started stocking Mystic (which you can get at walmart). And they claim that it has not degraded at all. Good and well, but the stuff is really "thick".

[dstevens]

Good find on the replacement seals Dave. I'm doing the hubs right now. Fronts are waiting for Brown to drop off a shipment of CV2. The fronts looked good, someone must have just done them. The rears though show like a donor with 163k miles. They are toast, scored and dragging. And the 12 ton press can't get the inner races off. Have to go see the boys at the machine shop.

How many of you paint the uprights, spindles and hubs? I've got them cleaned up, thinking of using silver caliper or engine paint.

[Ken Nesbit]

Thanks for all the info guys, repacking bearings is an easy enough job that it doesn't make sense not to do it...

[Tom Hampton]

Not me... but, i think Joshua fine painted his the same color.

[Bruce Wilson]

I have a question about the front hubs/bearings and what makes them wear out so quickly.

They don't wear out quickly, folks are just being proactive. I (and others) wait until they fail and buy new/blueprinted. Untouched, they can last about 2 years.

-bw

[rob20rx7]

Did my hubs last night! +1 on those intructions. Real easy and went smooth. went ahead and purchased 2 pairs of seals from Dave. I should have these puppies back on the car by Tuesday.

[FTodaro]

I repacked my spare hub today as practice for the hubs on the car. What a pain in the AS@ it was to get those bearing in the front carrier, After I got the hang of snapping them in and holding the cage with allot of pressure to keep it from moving out of position, It took me about an hr of attempts to develop that skill.

I asked this above, is the procedure any different for doing the rear hubs. all the posts of DIY are the front hubs?

[dstevens]

Follow the instructions that Tom Hampton got from Karl Zimnmerman's site posted at the site in Tom's sig. The trick is to get a bearing in each of the corners to hold the ring in and it indeed requires some dexterity. The rears I understand are to be replaced as an entire unit. If you do separate them it causes damage. I had to send the rear hubs to the shop with a 50 ton press to get what I call the "inner" race (even though it's the outboard side) off the hub. He said it took about 25 tons to remove them. I got some Timken replacements at NAPA for sbout 30 bucks or so each.

[Keith Novak]

There is an easier way I picked up working as a bicycle mechanic many moons ago in a shop with a solvent tank and compressed air after repacking bearings the hard way...

Leave the bearings in the retainer. Use solvent, rubber gloves, and a bristle brush to get the heavy stuff out. Use safety glasses and compressed air to blow the other crap out. Lather, rinse, repeat. When you're pretty sure the only thing you're blowing out is clean solvent, hit the next hub. When you're done with the last hub, the solvent will have evaporated in the first hub...add grease. Once you've greased the first hub, the solvent will have evaporated in the 2nd hub.

You'll never break a bearing retainer that way. It's quicker, and less frustrating. I could probably repack a set in the time you'd curse trying to get the bearings out of one hub.