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Rear wheel bearing or other cause?

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Chet Zerlin

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Hello all,

Driving my 100-6 the other day I heard a clunking sound coming from the rear of the car when I applied the brakes. After checking to make sure the wheels were on tight I jacked up the car and removed the left rear wheel. I found there was in/out play on the hub. (see video below)


As you can see everything was dry at this point but when I removed the hub (single screw) and pulled the half shaft out (to check tightness of the hub nut) fluid leaked out however the hub nut was tight and the lock washer was properly seated.

Questions: would the movement/play shown in the video indicate a bad bearing? Bad oil seal? Or is that "normal"?

Any and all suggestions on what this might be and what I should check are greatly appreciated!

Chet
 
Coincidentally. I have a complete set of Timken rear end bearings and seals I do not need.....................................
 
Your description--I couldn't play the video, it says 'Please sign in'--sounds more like a U-joint problem (much easier to remedy). I had a rear hub bearing start to fail; it manifested itself with a clunk or other noise--don't recall for sure--when hard cornering in one direction only.

BTW, if you got oil on the lining of a brake shoe it should probably be replaced, though you might be able to clean it up.
 
The video tells me: "This video is private."
 
Chet--

I am able to view the video. It would be helpful if it were a bit longer but it looks like you are pulling out on the hub and it is loose on the end of the stub axle. You say the "BIG NUT" is tight and if that is the case it sounds to me like there is play within the hub itself. I would suggest removing it and checking the condition of the bearing and the hub itself. Also if there is a spring ring make sure it is in place, etc.

Don't worry about the bit of diff oil that came out when you pulled the half-shaft--that is normal and is not a sign of seal leakage. However, oil in the brakes, etc. would be.
 
It does look like a lot of movement.

The inner race should be locked tight by the nut/lock washer you checked and the outer race should be pinched in the hub by the axle flange pressing against the spacer #61 and should be locked tight - there shouldn't be any more movement than the bearing itself allows.

Is the spacer (Moss #61) there? The paper gasket (Moss #48) may be too thick, a lot times it's necessary to make your own out of varying thickness paper as required to get a light pinch to make sure the outer race can't spin.
Dave
 
Thanks everyone!

Dave, now that you mention it I don't remember seeing that spacer when I pulled the half-shaft. That's the first thing that I will check tomorrow. First time I've worked on that side since I got the car so I have no idea what was done by the PO. Hopefully that's the issue!

Chet
 
Here's what I found yesterday when I took a close look at everything:
1) While the nut and the lock washer were tight and correctly installed ....there was no spacer (!)....
2) The in/out play on the hub consists of the hub moving and the bearing remaining stationary. I am able to move it rather easily in and out about 1/8" by pulling or pushing on the hub.

My suspicions are that the lack of the spacer resulted in loosening up the pressed fit of the bearing inside the hub (spun bearing?). So my belief is that the correct fix is to replace the bearing and the oil seal and reinstall everything with the needed spacer.

Do you all agree?

Chet
 
My suspicions are that the lack of the spacer resulted in loosening up the pressed fit of the bearing inside the hub (spun bearing?). So my belief is that the correct fix is to replace the bearing and the oil seal and reinstall everything with the needed spacer.
Click to expand...

The bearing to hub fit is a very light hand press fit not requiring a press usually. The bearing outer race needs to be snug in the hub but that's all and the pinch between the axle flange and hub is what keeps the bearing form spinning so there may have been no damage done to the hub. You may not even need new bearing/seal although I would be tempted to install a new seal just because it's easy at this point.

The important part is the amount of "pinch" when assembled and that is why you may need to make your own gasket to get it right. You want enough pinch to prevent the race spinning but not enough to distort the hub. The rubber o-ring seal gets compressed also and can make you think the bearing is tight even if it's not, so I would dry fit it all without the o-ring to check the bearing pinch, then re-assemble with the o-ring once you know it is fitted correctly.

Others may have their own preference but I like to coat the gasket and o-ring with permatex 300.

Dave
 
Dave,

Thanks for your reply but I'm not exactly sure what you are saying is the cause of the in/out play between the hub and the bearing.....is it what I indicated above or is there a different explanation?

Thanks!
Chet
 
Chet,
Sorry for any confusion. Yes, unless the bearing itself is failing (in/out movement between inner & outer races), I think you have described it perfectly and the bearing outer race is sliding in & out in the hub which will get pinched by the spacer ring and the axle flange when assembled.

Said another way... When you pull the hub outward on the bearing and put in the spacer ring, the spacer ring should sit slightly proud of the gasket surface of the hub (.001-.004") so that when the axle is inserted and tightened the outer race is compressed in the hub 'pinching' outer race and preventing any in/out movement.

If you have the Bentley Book, page 208 has an exploded view that shows the spacer ring (but oddly enough does not show the o-ring) and same page describes installation. BTW, I just went out I measured one and it was .184" - not sure if there is a variable in them or not but there is your 1/8+ movement.

Dave
 
FWIW, the couple times I've replaced rear bearings the bearings had to be pressed out and in of the hub with a 2-ton press. I gotta believe if the bearing moves in and out of the hub it's been spun in the hub. Or am I missing something?

Side Note: The last time I put a hub back on the axle housing I thought I'd be clever, warmed up the hub and rubbed a chunk of dry ice on the housing to 'shrink' it so I wouldn't have to pound on the bearing so much. When I rubbed the ice on the housing, it started to 'sing' very loudly, like a huge, loud tuning fork (I'm all but tone deaf so couldn't tell you the note). I have no idea what laws of metallurgy or physics would explain this, but it didn't sound/seem 'right' so I stopped doing it, and proceeded to just hammer it on with a 2" tube of steel and 4lb sledge.
 
Get Lock Tite Bearing Mount Stick. You may want use the spray primer first. Rub the glue stick onto the outside race of your new bearing and also inside the hub. Press or pound new bearing into hub. Best cure for spun hubs.
Also, forget the paper gasket. Place a bead of RTV instead.
Good luck.
Douglas
 
The lock tite bearing retaining compound, green, also comes in liquid.
All the sprite hubs (most BMC) and bearings are a hand press fit. I have had many rear bearing hubs and bearings and none of them ever needed to be pressed in. All just needed a gentle tap.
The Locktite green helps out with the design where the axle pressed against the outer race to keep it from spinning.
 
My 100 used to clunk as you describe. I always wondered what was causing it. I finally discovered it was worn hub splines. Free play in the forward and reverse direction on the hub produces a discernible clunk, especially when the brakes are applied. You would think that tightening up the knockoffs would stop the noise, but it did not. Replacing the hubs and wheels with new ones eliminated it, those splined hubs are supposed to fit snugly on the wheels with almost no fore and aft play.

The end play in your axle doesn't seem right, but I'm not sure that would produce a clunk on braking or accelerating.
 
Side note - we have already proved (previous threads) the Moss gaskets are too thick. As compressed they are around .009" thick and you need .004" or less to properly clamp the outside of the bearing and keep it from spinning. Copier paper is about that. Permatex or Hylomar plus the o-ring should do the trick.

Tom of Tom's Toys told me he had replaced 80+ rear bearings due to being spun. IMO the use of these too-thick gaskets is causing the spinning as the outside is not being properly clamped per the manual.

PS - in my case, putting the hub in direct sun for an hour and the bearing in the freezer resulted in my being able to tap or push the beariing in place.
 
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