My driver's side rear wheel bearing is starting to grind and seems to be getting rougher sounding lately. I searched and found a few write-ups, but it appears replacement is a huge PITA. Any tips anyone can offer??

I think from reading the hub with wheel studs has to come off the axle spindle and then the toe hub has to come off to remove the bearing. But I am not clear on the hub?? Is there bearings in the wheel hub as well? Thx (90 convertible)

 

The "hub carrier", also known as the triaxial floating hub comes off the car. Inside will be the bearing and the actual hub. The hub will have to be pressed out of the bearing and then the bearing out of the carrier. Trying to press out the hub will likely destroy the bearing and then the race will need to be removed from the hub as it will likely stay.

I may have some pictures of this in my restoration thread. Check page 8 or 9. I am on a tablet, so it is a bit cumbersome to find, otherwise I would just link you.

 

they don't normally "grind" in my experience... just develop play. Are you sure it's not just your brake heat shield rubbing on the rotor?

 

agreed, grinding doesn't sound like a usual bearing noise. i've heard them make a howling noise when they wear enough to become loose and a helicopter sort of noise when they get a flat spot on a roller/ball

it wouldn't hurt to look into it further, jack up the rear end, pull the wheel off and spin the brake disc, see if you can pinpoint the noise. grinding could be many things, a bent heatshield like eage8 said, little rock or chunk of gravel stuck in between brake pad and rotor, maybe even a torn cv boot that got a bunch of dirt in it.

also with the car jacked up and the wheel on and bolted tight, grab the top and bottom and give it the wobble test. side to side wobble test too, but that might be harder to tell if you have old worn dtss bushings.

i hope it's something simple. i've not done wheel bearings on my fc yet, but they are never fun on any car

good luck

-sean

 

I plan to jack up the rear end today and see if in fact it is the bearing. As for the sound it does have somewhat of a helicopter sound to it. I can hope and wish it is the dust shield and I'll check. I thought maybe axle too.

JerryLH3, I found them. Great pictures to help me understand how the bearing goes in. I remember looking at your thread in the past - that was some restoration! Amazing.

 

Raised the rear end and so there was no play in the tire side-to-side and verified dust shield wasn't scrubbing when I spun the tires. I noticed there is a clunking sound eminating where the axle boot where it disappears into the dog bone thing (the white strut is blocking the area I'm referring to). So I guess either the bearing or axle??

 

Pull the axle out and rotate the CV joints around by hand. A little bit of resistance is ok (the grease inside the joints/boots is very thick) but movement should feel smooth. Any grinding, notchiness or clunking in the action of the joint means you found your problem. With the axle out, spin the hub and brake rotor some more and see if the noise persists.

Axles aren't cheap, but way easier to replace than bearings. Unfortunately by the time a CV joint starts making enough noise for you to notice, it's likely already beyond repair.

Keep us updated!

-sean

 

I won't make progress till next weekend because I'm trying to finish my Probe tie-rods this weekend, but if you take the axle out doesn't that destroy the bearing? I could be mistaken, but I thought I read that earlier in searching.

 

Nope that's if you press the hub out of the spindle. The axle slides into the hub, the bearing is between the hub and the spindle. Pulling the axle out shouldn't have any effect on the bearing



-sean

 

So I take the axle nut off and caliper / rotor and slide the Toe hub, dust shield and hub off the axle spline as one assembly? A lot of work but not too bad I guess. Thanks for the IPB blame.

 

Correct. Those all come off as one assembly once the caliper and rotor are out of the way. It's not too bad, but those hub carrier bolts can be a PITA.

Actually, the bolts aren't so bad, but getting the sleeves pushed to one side can be.

 

I went to Mazda dealer to get new axle nuts and they don't have them. So I figure since I'm gonna remove and inspect the axle I figure with 204K miles on the original axles, I probably should replace them while I'm doing this. Any recommendations on where to get remanufactured axles?? No real reason but I don't want Cardones.

JerryLH3, your restoration page stopped at page 10. Just wondering how your seats turned out?

 

As long as the axle isn't broken, I wouldn't worry about replacing it.

As far as my seats, I have a nice set of seats from another car that I will use as donors for the foam I need replaced. I haven't quite decided if I am going to have an upholstery shop do the work or buy some replacement seat covers and do the work myself. That is on the agenda soon. I'll probably be updating the thread shortly as well. I know it's been awhile, but work has not stopped. Still trying to go at a feverish pace so I can finish this year. My goal is to be painting in April and "done" soon thereafter.

 

I was talking to a Miata racer and his buddy actually rebuilds RX7 axles at ISC Racing in Winterhaven FL. I talked to him and bought a couple. He didn't want the cores so I'll keep the originals as back up if the grind noise isn't the axle. I may try rebuilding one to learn something.

Anyway, question is what tips does anyone recommend for axle removal? I figure I can remove the 4 nuts at the differential, pry off that end, then remove the axle nut and try to rubber hammer the spline through. Anyone do this, or is it easier to remove the toe hub as an assembly off the axle?