Ruined Wheel Hub?

[Tweeds]

Boys, I've ran into another snag. This time it's on the other side of the car. I broke the outer bearing when torqueing down the nut, but that happened long ago and isn't the issue here. I got this bearing kit from zcardepot, and figured I'd go ahead and replace both bearings, not just the broken one. The inner bearings for this kit, however, have given me nothing but problems. As shown in the picture, the bearing gets stuck on the stub axle each time I put the hub on by which I mean when I pull the wheel hub off the axle, the bearing stays on the axle rather than staying in the wheel hub. The bearing won't go any farther down the axle than it does in the picture either, and even to get it to that point requires a bit of force and wiggling. It's not a problem with the axle stub (it being bent or something) because the old bearing still fits on without issue, and both bearings from the kit have the same fitment problems on both sides of the car. Because the hub doesn't seat correctly with these bearings, the nut can't be tightened enough to leave room for the cottar pin, as shown in the second picture.

I tried manually positioning the bearing farther up the axle (where it ought to be) by lightly hammering it farther up, then putting the hub over top of it. Even so, the nut couldn't be tightened enough to insert the cottar pin, and the hub, when rotated, made terrible noises, and rotated unevenly by which I mean it would rotate smoothly and freely 3/4 of a turn, but then have have a bit of resistance for the next 1/4 of the turn. This problem may be with the bearing, or because part of the dust shield was somehow bent inwards (shown in the last picture), or a combination of both. I did my best to bend and grind the dust shield back to where it's supposed to be. I may not have done a good job of it, and may need to do it again a bit more precisely, but I'd like to rectify the bearing problem first. My z is a '71, so my only thought is that maybe there is a slight variance in the hub/axle assembly from later z's, making these new bearings ever so slightly too small. Either way, the bearing kit was advertised to fit all z's from 70-83. Worst comes to worst, I can just put the old bearing and race back in the hub and hope everything works out, but I don't think that should be necessary. That would mean I bought a full bearing kit for one of the bearings. 

[Zed Head]

Any part numbers on the bearings? Should be stamped on the edge of the race.  Those bearings are very common.  No need to go to a specialty shop like ZCD.  OReilly Auto is fine, then you can swap them out easily if they don't fit, even if they're greasy.  Too late now, I just mention that to make you feel bad. 💀

That bearing inner race should slide easily down to its seat at the base of that spindle (proper word for it).  Clean the grease off and look for a burr or lip on the spindle.  The bearing really should be just a hand press fit, no hammering/tapping or force required at all.  Nobody checks the fit before they install the bearings and the seal but we all should.

https://www.oreillyauto.com/detail/b/national-2929/wheel-bearings-hub-assy-seals-25107/bearings-and-seals-25072/wheel-bearing-12839/5426c6f5d17c/national-tapered-bearing-set/a2/2552840/1974/nissan/260z?q=wheel+bearing&pos=3

https://www.oreillyauto.com/detail/b/national-2929/wheel-bearings-hub-assy-seals-25107/bearings-and-seals-25072/wheel-bearing-12839/5426c6f5d17c/national-tapered-bearing-set/a6/2552881/1974/nissan/260z?q=wheel+bearing&pos=4

[Tweeds]

Timken LM67010 is the part no. Cleaned the grease off, and as far as I could tell, everything was intact. The only thing of note were a few small gashes I imagine were made by a screwdriver when I had to pry off the bearing.

[Zed Head]

5 minutes ago, Tweeds said:

The only thing of note were a few small gashes I imagine were made by a screwdriver when I had to pry off the bearing.

It's a hand press fit but it's still a very close fit.  A gouge might be enough to screw things up.  Might be that you just have a + size spindle and/or a - tolerance bearing.  A little work with a scotch brite pad might be enough to size it down.  Good luck.  Welcome, as others have said, to old car world.

[grannyknot]

Just to add to ZH's excellent advice, if you rub your fingers around the base of the spindle where the inner bearing sits it should be completely smooth, no irregularities.  If there is remove them by lightly using a fine single cut file.  Also, all that grease that is outside of the dust shield needs to be cleaned off or it might contaminate the rotor and pads.

[Tweeds]

Since the old bearing fits on fine, do you think I'd be better off reusing it rather than tampering with the spindle to fit on the new bearing? I plan to clean all the excess grease once everything is in order - the grease manages to get everywhere so long as I am still moving things around.

[grannyknot]

You can't use an old bearing with a new race, well, you can but the bearing will fail quickly. They won't match.

[Zed Head]

1 hour ago, Tweeds said:

 I broke the outer bearing when torqueing down the nut, but that happened long ago and isn't the issue here.

Worst comes to worst, I can just put the old bearing and race back in the hub and hope everything works out, but I don't think that should be necessary. That would mean I bought a full bearing kit for one of the bearings. 

How did you break a "bearing" (what actually broke?) by torqueing down the spindle nut?  You should be able to put everything together by hand, almost to the point of even setting the nut if you have strong fingers.  No need for force, except for removing the races from the hub.

To grannyknot's point, if you use the outer race that came with the bearing you could just put it back the way you took it apart, on the inboard side, then use the new matched bearing and race on the nut side.  But you don't want to use a different outer race with a new bearing.  

Sometimes parts just don't fit.  I had to chisel a new pilot bushing out of my crankshaft after I got it halfway inserted.  It was just too big.  The replacement fit just fine.

[Racer X]

2 hours ago, Tweeds said:

Boys, I've ran into another snag. This time it's on the other side of the car. I broke the outer bearing when torqueing down the nut, but that happened long ago and isn't the issue here. I got this bearing kit from zcardepot, and figured I'd go ahead and replace both bearings, not just the broken one. The inner bearings for this kit, however, have given me nothing but problems. As shown in the picture, the bearing gets stuck on the stub axle each time I put the hub on by which I mean when I pull the wheel hub off the axle, the bearing stays on the axle rather than staying in the wheel hub. The bearing won't go any farther down the axle than it does in the picture either, and even to get it to that point requires a bit of force and wiggling. It's not a problem with the axle stub (it being bent or something) because the old bearing still fits on without issue, and both bearings from the kit have the same fitment problems on both sides of the car. Because the hub doesn't seat correctly with these bearings, the nut can't be tightened enough to leave room for the cottar pin, as shown in the second picture.

I tried manually positioning the bearing farther up the axle (where it ought to be) by lightly hammering it farther up, then putting the hub over top of it. Even so, the nut couldn't be tightened enough to insert the cottar pin, and the hub, when rotated, made terrible noises, and rotated unevenly by which I mean it would rotate smoothly and freely 3/4 of a turn, but then have have a bit of resistance for the next 1/4 of the turn. This problem may be with the bearing, or because part of the dust shield was somehow bent inwards (shown in the last picture), or a combination of both. I did my best to bend and grind the dust shield back to where it's supposed to be. I may not have done a good job of it, and may need to do it again a bit more precisely, but I'd like to rectify the bearing problem first. My z is a '71, so my only thought is that maybe there is a slight variance in the hub/axle assembly from later z's, making these new bearings ever so slightly too small. Either way, the bearing kit was advertised to fit all z's from 70-83. Worst comes to worst, I can just put the old bearing and race back in the hub and hope everything works out, but I don't think that should be necessary. That would mean I bought a full bearing kit for one of the bearings. 

You should never need to use force to assemble wheel bearings. 
 

Take it all apart, clean everything up. Inspect the spindle where the bearings slide on, and if there are any burrs, clean them up with a strip of emery cloth. Then see if the new bearings will slide into place.

Also, measure the ID of the bearings, and the OD of the spindle. You should have a couple thousandths of an inch of clearance.

Once you get it sorted out, and things are slipping together properly, grease the bearings (also, don’t pack the journals full of grease, it isn’t needed and wastes grease), drop the inner bearing into the hub, install the dust seal, slide the hub and bearing onto the spindle, then insert the outer bearing, washer and nut.

Tighten the nut by hand, while spinning the hub. When you get it as snug as you can by hand, then use a socket, and a 3/8” drive ratchet to set the bearings while again rotating the hub.

 I believe the service manual specifies a torque, but I usually snug by feel, then back the nut to the first point the nut lines up with the cotter key hole, then insert the key, and replace the dust cap.

There should be a very small amount of free play.

 

 

 

[Tweeds]

Sorry, I could have been more specific. I meant reuse the old bearing and race. I still have them lying around, cleaned up, repacked and everything. I broke the original outer bearing following the FSM's procedure for tightening the nut where you torque the nut down to around 19lbs +/- a pound, then back off the nut about 45 degrees. Something like that. I thought my wrench hit the ground, when in reality it had clicked, so I ended up over torqueing the whole thing - the inner and outer race of the bearing itself became dislodged, and all the rollers came free. In short, the bearing fell apart. After doing all this, I realized that whole tightening procedure is somewhat unnecessary, and you can pretty much tighten the nut by hand, as Zed Head said, or else just use a regular socket wrench if needed, but, oh well, figured that out too late 😕 

[grannyknot]

2 hours ago, Tweeds said:

Sorry, I could have been more specific. I meant reuse the old bearing and race.

I was assuming that was the race that was cracked. Yes you could use old inner bearing and race with new outer bearing and race but you don't want to keep it like that for very long.  Every time you take that inner bearing and race out there is the chance of twisting, scratching or damaging them in some way besides the fact that they are old and probably worn out.

Considering how inexpensive those bearings are you might want to cut your loses and pitch them in the bin, get yourself a different set from another supplier.

FSM says to torque that nut for a reason, it's to make sure that the inner bearing and both races are fully seated against the hub and bottom of the spindle, hand tightening that nut isn't going to do that.  After you back off the nut then it can be finger tightened.

Edited December 5, 2020 by grannyknot

[Zed Head]

6 hours ago, Tweeds said:

Boys, I've ran into another snag. This time it's on the other side of the car. I broke the outer bearing when torqueing down the nut, but that happened long ago and isn't the issue here. I got this bearing kit from zcardepot,

I don't know if this means anything and I'm not insinuating (purposefully, although it is there) but it's weird that the ZCD kit is so inexpensive.

The OReilly parts would be 2x13 and 2x15 for a full set of National bearings.  26 + 30 = $56. 

ZCD's full set is just $39 for Timken bearings.  Something seems off.  Don't know, just saying...

p.s. and I didn't include the seals.  About $7 for the inexpensive ones.  $63 total for an OReilly kit.

Edited December 5, 2020 by Zed Head