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Rear Wheel Stub Axle Play - Help Needed


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Hope someone can help, been strugling with this for awhile.  I recently reassembled my rear stub axles in the strut housing (with the spacer that came out of it and new bearings), installed the companion flange and tighted the locking nut.  I did an inital assembly and everything went together fairly well, but I found that by grabing the rear brake disk (AZC five lug conversion) there was very slight axial play, I would guess about 1-2 thousands.  I tried to tighten the nut further and did so up to 250 ft lbs but this made no improvement.  I have verified that the play is in the stub axle / wheel bearings and not in the suspension or shock to strut inerface. And I am seeing this on both rears not just one.  Any thoughts or experience on this is appreciated.   My car is a 1975 280Z.   Thanks

 

-Colin

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About the only place for play is how the bearings sit in the casting if everything else is tight and new. Are you sure there is no play in the rotor to stub flange connection you're grabbing to test? Take the rotor off and measure the stub axle flange movement and see what happens. Being same on both sides is suspicious.

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There can  be play in the four bolt stub axle flange that the half shaft bolts to.  The splines in the stub axle flange can get sloppy. Set the brake and try to turn the four bolt stub axle flange.

 

 

See 4 bolt flange:  http://www.zparts.com/zptech/illustrations/750w/DCP_1490rw1s.jpg

Edited by Miles
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Z240 I hear what your saying but I am able see the companion flange move when I push/pull on the rotor. So I don't think it is the rotor to stub interface. Looks like the companion moves a few thousands but hard to tell with out at dial indicator. The wheels turn very easily which also has me concerned as it I measure about half the force I see in manual. Manual says force to rotat wheel should be about 16oz (if I remember correct) and mine measured about half that.

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Tapered roller bearing vs. ball bearing. 

 

 

Edit for clarity - the rotational torque spec. is for the front tapered roller bearings.  Torque on the nut determines rotational force in the bearing.  The spec. for the rear roller bearings is just a range of shaft play, since the ball bearings need a certain amount of room in their races to work properly.  If you get it too tight the balls will ride up the side of the race.  Too loose and the inner races will move around.

Edited by NewZed
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Thanks Zed, makes a lot of sense.  I'm going to borrow a dial indicator this weekend and check axial play. Maybe its is OK but I am now doubting it.  The movement is pretty small, but there is a audiable clunk when I push and pull on the brake disk (I've not heard of others having this, except with worn bearings), and like I said the only place I see movement is the companion flange moveing in and out a little so I do think it is the stub axle moving realative to the strut housing. 

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Ok so i took it all apart and can see nothing wrong. The spacer ("B") matches the casting marking, the outside bearing looks to be installed correctly and properly seated. I confirmed the outside bearing is the right part number. The inside bearing, though hard to see, looks like it is seated. The only thing I noticed is that I don't have a washer between the lock nut and the companion flange, therefore when's tightening the nut i may be bottoming out on the shaft threads I'm preloading the bearings. Does everyone else have a washer here? Black dragon shows a washer in their catalog but the couple of manuals I looked at don't show one. This is killing me, as its the only real thing I need to do before taking the car out for the first time, it's been about 8 years since I started working on it.

Edited by Wheeler
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Some 240's had a copper washer between the outer flange and the bearing, but this is not a requirement. I was installed for noise absorbtion, not spacing. The copper washer does not fit on the large dia 280 stub splines, so you're not missing anything. Could be just play in the bearings. Axial is not a big deal, radial is. Run and see what happens

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According to the Techncial Bulletin in Humble's "How To Restore..." book, page 196, Nissan stopped using the noise-reducing washer in 1974, after RLS30-32966 (I'm just repeating what he wrote, I thought the S30's were HLS.  Might be a typo.).  The Bulletin is apparently dated 8-3-74. 

 

Is there a reason that you don't want to use the factory specification, or does the wiggle just make you uncomfortable?  You never said what you measured with the indicator.

Edited by NewZed
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I think we are getting apples and oranges. There are two washers: the copper washer which seems to be optional (I don't use it) and a thick heavy steel flat washer under the but nut. I use a big washer under the nut. I'm not sure if this would cause insufficient preload or not.

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It has both radial and axial play. Going to get a washer to put under the nut to ensure I am getting preload and not bottoming the nut out at the end of the threads. All I can think of short of getting another set of new bearings or just start drinking.

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According to the Techncial Bulletin in Humble's "How To Restore..." book, page 196, Nissan stopped using the noise-reducing washer in 1974, after RLS30-32966 (I'm just repeating what he wrote, I thought the S30's were HLS.  Might be a typo.).  The Bulletin is apparently dated 8-3-74. 

 

FWIW, the 260Z prefix was "RLS30". R means L26, H means L24 or L28, depending on model.

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  • 2 months later...

So I think I have tried just about everything. I removed the worst side and then assembled it in the bench (stub axle, outter bearing, spacer, and then the flange). Tightened it all down and then measured the space between the companion flange and the spacer to verify that I able to preload the outer bearing when assembled in the car and that the flange did not bottom on the spines before it contacted the outside bearing or that the nut ran out of threads before the companion flange contacted the inner bearing inner race. It all checked out ok. I then replaced the inner bearing with an another new one and putti back together and it seemed pretty good. At this point I said screw it and drove the car! (First time ever and it was awesome though a little loud with no exhaust and no windshield). Now it just checked it agian and it is again slightly loose. Any other thoughts. Should I be able to increase the resistance to wheel turning by adding torque to the nut? I've heard many say that you should tighten until the resistance is correct.

 

I did try drinking and it only helped for awhile, will try again....

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Sounds like you need a different sized spacer between the bearings. Ive fought this before and it's quite frustrating. Either shorter to bring the inner races together or longer one to move the inner races appart either way to take the play out. I ended up getting shims from McMaster-Carr and trial amd error shimmed it until it was tight. I've read procedure where you take a fish scale and pull on a wheel stud and tighten the nut until you get to a certain full force. I found that the nut torque doesnt impact rotation torque at all. You have to keep trying shims until you get the torque preload. The first time I shimmed it, the shim was so thin it basically fell appart. Luckily I found this before the bearing was damaged. I assume this happened because the nut wasnt tight enough? Now after every race I wiggle the tires to make sure the bearing are staying tight.

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Thanks heavy. Good to know that I'm not the only one seeing this. I was thinking of milling about .002 off the spacer and trying that to preload the bearings as right now I don't think I am at all. Do you remember what thickness spacers you were playing with? I just want to make sure I'm in the right ballpark.

Edited by Wheeler
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Sounds like you need a different sized spacer between the bearings. Ive fought this before and it's quite frustrating.

This might help.  The spacer distance needs to match the housing.

 

Don't forget that engineers design bearing assemblies for hot running, not sitting still and cold.

post-8864-0-93244500-1377464716_thumb.jpg

Edited by NewZed
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  • 2 months later...

This might help.  The spacer distance needs to match the housing.

 

Don't forget that engineers design bearing assemblies for hot running, not sitting still and cold.

Thread revival

 

That's helpful but I still cant find any marks on the casting.  I've looked inside and out in the are marked in the FSM but I cant find anything.  The spacers clearly have 'B's stamped on them but nothing I can find on the upright casting.  The shim idea I mentioned above is not a long term solution as the shims keep squashing out.  Anyone have more details on where to find the mark on the upright?

 

Both of my 'B' spacers measure way under the spec listed in the FSM which is probably to real root cause.  Any ideas where to get replacements?

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