Decided to replace my front wheel bearings. Took them apart, cleaned, and this is what I saw. Im not sure if this is ok or not. The spindle looks to me like it has a lot of wear, like a race was spinning instead of the bearing. This is my first time replacing wheel bearings, so not sure if it supposed to look like this. Also if the spindle is bad, where do I buy a new one?

 

You are probably fine. Mine look like that too and have no issues. If there is wear you can feel with your fingernail report back.

 

Yes, I can feel a small step in the third picture, where it goes from light to dark.

 

Dry fit the bearing. If there is no slop, run it. Again, all the used spindles look like that. I think it is just a combination of heat cycling and grease penetration. If the bearing was really seized and spinning on the spindle it would do a ton of damage and you'd see bluing of the spindle from heat, which there is none.

The races you have shown look great as well. I don't think you had any problems.

 

Just dry fitted the bigger inner race on the spindle, could not feel any slop. The race did however spin with the bearing. Is it supposed to spin? What if I score / make grooves with a punch on the spindle, then press the inner race to prevent it from spinning? I have Koyo bearings by the way. This whole thing seems like a bad engineering by Mazda...

 

I have had the new race spin in the spindle before, though I can't remember if I replaced that spindle or not.

It's just old school mechanical design, not exclusively Mazda's fault.

 

Remember the spinning hub is going to take the path of least resistance, which will be the bearing, not a spinning race on the spindle. If your bearing locked up, you'd have a problem.

If you are packing the bearings and setting the preload properly, there should be no issue.

I had a new Koyo race with an OD that was slightly too small and just fell out of the hub about 6 months ago. I always dry fit the bearings now before I grease them to make sure everything fits properly.

 

Actually with the bearing packed, the race will have least resistance, specially if it's cold outside. If it spins dry, it will definitely spin with heavy grease in bearings.

 

I've never seen the inside race of the inner bearing not have some resistance to being removed from the spindle (all cars with this style, not just RX7). Most of the time the disc or drum comes off and leaves the inside race of the rear bearing on the spindle after pulling it through the seal or removing the seal also. They usually have to be coerced off with a chisel and then a puller. That being said I am just a shade tree mechanic with most of my experience on this set-up being old American rear drive cars.

Congrats if yours came right off, I guess.

 

That's what worries me. After I removed the nut and flipped it upside down, it just dropped with the inside race. I actually have another set which I took apart and spindle looked the same with inside race just falling down with no resistance after removing the nut.

I think I'm going to glue the inside inner race to the spindle with jb weld or something, or make grooves on the spindle and press the inner race on it so it doesn't spin.

 

I think you are trying to fix a problem that is not really a problem.

Remember the inner races are all preloaded when you assemble the hub. I've ran my hubs so hot they blew off the dust caps on the track before.. if the hub is greased and preloaded properly, you won't have any issues ever.

 

I wouldn't do that if I were you, do what LOF said and see if there is still a problem.

 

As LOF said, the assembly gets preloaded when you put the spindle nut on.

Just keep in mind the spindle nut requires a freakisly low amount of torque when you put it back on...also, dont forget the castle cap!

 

I do 25 ft lbs for the track. I used to do 20, but I'd have to retorque new bearings 2 or 3 times.

 

The factory manual procedure is to tighten the spindle nut until there is some resistance to turning the hub and then put a pull scale on a lug stud and loosen the nut until it takes 1.5-2lbs force to rotate the hub.

This is very very low torque on the spindle nut and you do have to periodically re-set the torque in a performance application doing it this way.

 

I think with the OE preload method I'd have to reset the preload 10-15 times with new bearings.

I have only had to reset the bearing preload with new bearings. If I am just repacking, they are set and forget, I've never had to retorque repacked bearings since going to 25 ft lbs on the spindle nut.

 

I realized I wouldn't be able to do this since I have to press the inner seal ring into the back of the hub after I insert the inner race / bearing. So I just did what the mazda fsm said. Got the hub back on and torqued all to spec per fsm.

When would be a good time to recheck my bearing preload / play? Not doing any track sessions, just street driving.

 

Spindles look fine. No wear on them at all.

 

I have never used a torque wrench on my spindle nut, ever. I just take a little 1/4 inch ratchet and (baby one) and use 2 fingers and my thumb to tighten it till it will no longer move. throw the wheel back on...spin spin spin till the wheel spins freely, take the wheel off and do the same thing with the baby ratchet. put wheel back on and spin, spin, spin, again and check the wheel doesn't wobble.

 

Drive a tank of gas or two through it. On the street it will probably be fine.

 

I don't even bother with that, I grab the socket with my hand. If anything, I'll grab the ratchet all the way up at the head so there's no mechanical advantage from the arm.

 

Used the torque wrench to 16ft lbs on the nut, spun the hub, loosened the nut and then tightened with socket in hand until there is roughly 2lbs drag on hub's bolt. Spun the hub several times and rechecked the drag again.

 

Just a follow up since I had my hubs off yesterday swapping bearings/hubs. I have the same markings on the spindle, but again everything looked great. I'm sure in some condition the race does move around on the spindle over time, but itis not spinning there constantly. If I just slide on the inner bearing the inner race did spin in the shaft. When it is preloaded with the nut I'm sure it spins normally. These bearings were repacked, so I torqued to 22 ft lbs this time. I'll see if they need a retorque after a couple heat cycles today.