After Karen's NASA HPDE day on Friday, looks like we need to replace the front bearings. Right one is pretty loose and noisy; left one is getting there.
So with a NB Miata one has to replace the entire Knuckle ... you can't just replace the bearing. This might actually be doable. Does one need anything special to pull the knuckles? I've had the suspension off at least four times in the last year anyway.
btw. Karen had a blast! Five 20+ minute sessions, an instructor the entire time, class room sessions and debriefs: $150. Very Well Organized!
This is pretty easy. Get the # 33-061 hub/bearing assy and the 33-042 nut. The nut is a "stake" nut, it's not reusable. Get the car in up on jack stands, take the wheel off, etc.
If the hub nut on your car is the same as my 1990 Miata you'll need a 1 1/8" socket to take it off. After the nut is off the hub/bearing assy. will slide right off.
Install the new hub/bearing assy and new nut, torque to (sorry I don't know that one) re-stake the nut. and you're done.
More info is here http://www.miata.net/garage/index.html" onclick="window.open(this.href);return false;
feel free to call me at the shop for more info
Thanks Steve ... and you think it's the same for a NB Miata? We've got the ABS sensor stuff to deal with also ... but it looks like it all can stay together.
The shop manual shows the usual special tool for removing the hub bolt?
Why does Mazda complicate things by calling it a knuckle instead of a hub ?! Even my korean Mazda mechanic was confused by what I was trying to say ... nothing unusual there though. He would charge $60 per side. I'll order the parts from MazdaSpeed ... and then see if I can take care of it myself.
Replacing the knuckle/spindle is also straightforward. It's held on by three nuts/bolts. One of the possible sticky points is separating the ball joint from the upper knuckle. Use either a ball joint separator that you can borrow from Kragen for the safe method or the carefully hammer on reversed castle nut or you're screwed method. When replacing the knuckle, you can also replace the dust boots for the upper ball joints and/or regrease if necessary.
I bought a cheap 3/4" drive impact gun & a set of 3/4" impact sockets at harbor freight just for getting this nut off a few years ago after breaking a 1/2" breaker bar. The big 3/4" drive gun has come in handy many times since.
Walter Wong wrote:or the carefully hammer on reversed castle nut or you're screwed method. .
Don't hammer on the reversed castle nut....... you hammer on the casting where the ball joint goes through. The tapered ball joint will drop out after a couple good wacks. You can also use an air chisel with a mushroom tip if you have one.
Walter Wong wrote:or the carefully hammer on reversed castle nut or you're screwed method. .
Don't hammer on the reversed castle nut....... you hammer on the casting where the ball joint goes through. The tapered ball joint will drop out after a couple good wacks. You can also use an air chisel with a mushroom tip if you have one.
Or a pickle fork and a 3 pound mallet. Buy a couple of ball joint seals while you're at. They tear from aging.
There's nothing different about the NA from the NB on the front wheel assembly. The bearing is part of the hub, that piece with the wheel studs in it. The steering knuckle does not need to be removed.
Walter Wong wrote:or the carefully hammer on reversed castle nut or you're screwed method. .
Don't hammer on the reversed castle nut....... you hammer on the casting where the ball joint goes through. The tapered ball joint will drop out after a couple good wacks. You can also use an air chisel with a mushroom tip if you have one.
Good info. Thanks. A bunch of very light taps on the side of the knuckle also helps shock the ball joint before you hammer on the casting.
Walter Wong wrote:or the carefully hammer on reversed castle nut or you're screwed method. .
Don't hammer on the reversed castle nut....... you hammer on the casting where the ball joint goes through. The tapered ball joint will drop out after a couple good wacks. You can also use an air chisel with a mushroom tip if you have one.
Good info. Thanks. A bunch of very light taps on the side of the knuckle also helps shock the ball joint before you hammer on the casting.
It's a lot easier if you just use a "pickle fork" and mallet. One good whack will separate them. You *might* tear the seal. If you keep a few spares, it's not a big deal.
Changed out the front bearing this afternoon. Very easy. The parts order form made it sound like one had to replace the "knuckle," but in fact there is a separate hub with the bearings in place. Taking my time, it took less then an hour. The hardest part was getting the Caps off. Had to tap a knife blade around it before I could get a screwdriver into the edge. Nice being able to take the brake calipers off with the disc. Nice saving $120 bucks ... what the garage was going to charge. And of course a nice savings using MazdaSpeed for the hub/bearings!
The passenger side bearing was the one that was quite loose. There was obvious heat scorching and the grease looked burnt. But only a few of the actual ball bearings looked damaged. One would have thought that they would be equally damaged? The left side bearing still looked OK, but there was certainly more then the 0.002" of allowable play.
Mako Koiwai wrote:Changed out the front bearing this afternoon. Very easy. The parts order form made it sound like one had to replace the "knuckle," but in fact there is a separate hub with the bearings in place. Taking my time, it took less then an hour. The hardest part was getting the Caps off. Had to tap a knife blade around it before I could get a screwdriver into the edge. Nice being able to take the brake calipers off with the disc. Nice saving $120 bucks ... what the garage was going to charge. And of course a nice savings using MazdaSpeed for the hub/bearings!
The passenger side bearing was the one that was quite loose. There was obvious heat scorching and the grease looked burnt. But only a few of the actual ball bearings looked damaged. One would have thought that they would be equally damaged? The left side bearing still looked OK, but there was certainly more then the 0.002" of allowable play.
The grease was full of shiny metal speckles:
did you happen to take a photo of the spindle? The reason they would tell you to replace the "knuckle" is if the spindle gets worn down too far. And it doesnt take much to mess it up. Especially due to heat.
http://www.osgiken.net
4 BSP- 2019 Mazda ND Miata - 2001 SSM Honda S2000
OS Giken / Bride / ShaftWorks USA
hmmm ... no photo, but "for some reason" the new bearing didn't go onto the "bad" side spindle as easy as the OK side. It seemed to get hung up on the inside edge between the two halves of the bearing. Cleaned the spindle and applied a touch of grease. Using the big axle nut socket against the bearing, I gave the bearing/hub a few love taps and it popped on. The inside edge of the spindle surface looked OK after I cleaned off the burnt'ish grease. What part on the spindle would get worn down?
One thing I noticed. The torque specs for the Axle Nut ranged from 120 to 160 ft. lbs. Since this as the Axle Nut I of course took it to 160 ft. lbs. Actually my torque wrench only goes to 150, so I went to the 150 click and then gave it a bit more. When I put on the other side I spun the hub around when I got to 120 and noticed it turned a bit easier then the side that I had done to 150+ ft. lbs. I left it at 120+ ft lbs. I was thinking of "redoing" the tighter side but the car owner said not to bother, I was within Specs ... and she's a professional Spec Writer. Should I ?
Mako Koiwai wrote:One thing I noticed. The torque specs for the Axle Nut ranged from 120 to 160 ft. lbs. Since this as the Axle Nut I of course took it to 160 ft. lbs. Actually my torque wrench only goes to 150, so I went to the 150 click and then gave it a bit more. When I put on the other side I spun the hub around when I got to 120 and noticed it turned a bit easier then the side that I had done to 150+ ft. lbs. I left it at 120+ ft lbs. I was thinking of "redoing" the tighter side but the car owner said not to bother, I was within Specs ... and she's a professional Spec Writer. Should I ?
you should not have "given it more". Back off the nut and retorque it to within specs.
http://www.osgiken.net
4 BSP- 2019 Mazda ND Miata - 2001 SSM Honda S2000
OS Giken / Bride / ShaftWorks USA
Well the high end was 160 ... and I went 150 plus a grunt, so I believe I'm still with in specs ... but it's not equal to the other side that was torqued to 120+
The added pressure did seem to make the torque plus'ed side a bit "tighter." I wonder since the torque range was from 120 to 150 ... if Mazda considers anything in that range to be just fine and dandy. Just like some car manufacturers set their toe specs to plus or minus 3 mm ?!?!?
Mako Koiwai wrote:Well the high end was 160 ... and I went 150 plus a grunt, so I believe I'm still with in specs ... but it's not equal to the other side that was torqued to 120+
The added pressure did seem to make the torque plus'ed side a bit "tighter." I wonder since the torque range was from 120 to 150 ... if Mazda considers anything in that range to be just fine and dandy. Just like some car manufacturers set their toe specs to plus or minus 3 mm ?!?!?
the difference from 150-160 is not much at all and so its easy to jump straight from 160-200+ with a little grunt.
I just think it would be best (before you drive) that you set the torques within spec and similar from side to side. It would eliminate any chance of another failure due to installation.
Just forewarning from my past experiences.
http://www.osgiken.net
4 BSP- 2019 Mazda ND Miata - 2001 SSM Honda S2000
OS Giken / Bride / ShaftWorks USA
I wonder since the torque range was from 120 to 150 ... if Mazda considers anything in that range to be just fine and dandy. Just like some car manufacturers set their toe specs to plus or minus 3 mm ?!?!? 
