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Rear bearing question

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JPSmit

JPSmit

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I was out looking at the rear axle today and I'm anxious that the hub is not tight on the gasket. there seems to be too large a space. (maybe 1/16") This causes me to wonder whether the bearing is properly seated. (There is no oil in currently as it's out of the car - so nothing leaks - yet)

I don't mind buying new gaskets & re-soing it but, before I do, any tricks to seating the bearing? Here's what happened.

I installed the bearing with a large socket, seemed tight - then, as I slid the bearing hub (#32) on the axle, the bearing slid out some - I pounded it flush (I thought) with the socket & some wood. The nut is torqued on but, then when I attached the half shaft, a gap remained

am I missing something? (BTW - not wire rims if that is relevant)

https://mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29295
 
Well, if the bearing moved by merely seating the hub, I would guess that either it wasn't seated properly in the first place, or the cavity it fits into has been worn too large. The bearing should be a light press fit into the hub. Maybe try doing it again using a press, rather than a hammer.
Jeff
 
I'll disagree *slightly*.

Mine did exactly the same thing during installation... No perceptible hub wear. In the end, I decided it wasn't really a problem; the bearing doesn't get cinched down until the axle is installed, anyway. The bearing certainly doesn't look an interference fit in the hub... and going from memory, the manual recommends assembly with both ID and OD surfaces greased, which makes me think they're not particularly worried about the bearing's outside surface rotating slightly. No mention is made of the bearing needing to be pressed to a certain tolerance (unlike my VW, which requires its bearings to be pressed to specs.)

Once bolted up, mine rolled cleanly. No untoward noises, it clearly wasn't seizing the bearing and rotating on the hub itself, if that makes sense! A couple hundred miles' use have shown no ill effects, but I suppose time will tell!
 
thanks Duncan - my concern is the gap between the bearing hub and the "cap" on the halfshaft - seems like there is the nut to hold the bearing on but only one screw to hold the "cap" to the paper gasket around the bearing (and then the two screws for the brake drum) and then the 4 wheel studs. all of which doesn't seem like a real tight fit for the gasket - thoughts?
 
The wheel studs hold it real tight. The screw is just to keep it snug till you get the wheel on.
 
Exactly, what Jack said. The whole ass'y is laterally located by the body of the hub, the large retaining nut / crush washer, and the fact that the wheel is bolted on tight.
 
Bugeye58 said:
Well, if the bearing moved by merely seating the hub, I would guess that either it wasn't seated properly in the first place, or the cavity it fits into has been worn too large. The bearing should be a light press fit into the hub. Maybe try doing it again using a press, rather than a hammer.
Jeff
Click to expand...
I agree with Jeff. The bearing needs to be tight in the hub, especially on these cars with a single bearing. The only thing designed to keep the bearing in the hub is the interference fit of the bearing OD. The flange on the axle is not designed to handle the job of locating the hub. Think about the splined end of the axle, there is nothing there to prevent the axle from sliding inward other than interference with the end of the machining of the splines. Movement on the hub side would allow the axle flange to contact the end of the housing tube, a bad situation. Both these scenarios assume that there is plenty of clearance with the brake shoes and drum which there isn't, the drum and shoes or backing plate would end up hitting first I would think. If you can move the bearing in the hub without a press of hammer there is a problem.
 
Chris,

I want to confirm that we're talking about two different things.

The inner surface of the hub is flat, with no taper or step. Once the bearing is in, even on a hub with no visible wear, it is not impossible for it to slide out slightly and need to be pushed back into place, particularly during reassembly.

Once the whole assy is bolted together, that can no longer happen. The action of bolting in the axle pulls the hub outward, positively locating the bearing. The friction fit of the bearing itself cannot, as far as I can see, be responsible for limiting either inward or outward movement of the wheel / hub / axle ass'y. Both are mechanically limited.

Certainly, if the ID of the hub shows wear, it should be renewed. But I don't think that lateral movement of a greased bearing, in a greased hub, before final assembly is necessarily an indication of a problem.
 
Southern car was pretty close in the above post.

There are two ways to get the rear back together....the right way and the pray way. The pray way of course is .."well I'll just throw it together the best I can...and PRAY". Take your choice.

The hub bearing should be an interference fit in the hub.
About .001" The bearing should not flop around in the hub. If the i.d. of the hub (the bearing o.d. surface) is shiny and polished, the bearing has been moving around.

So to get a decent fit on an old hub..you must peen or kcirp (read this backwards else it will be censored) punch the i.d. bearing area of the hub to provide a snug fit. Push or press the bearing in the hub and make sure it is all the way in the hub.

Then.....use a straight edge across the face of the hub and with small feeler guages see what the diference is from the bearing front face to the hub face. The bearing can be inboard from the hub face or ouboard (outside) the hub face.

The GASKET sets the hub END PLAY. The gasket thickness called for by oem is .008". This is supposed to give about .002" end play in the hub but still may not get you the correct end play. These figures translate into (example) bearing .003" + (out from the hub face) and an .008" gasket will give .005" end play which is too much. You need to make a gasket from some .005" shim stock and arive at .002" end play which is more than enough. You can shim the back of the bearing face but you have to make a nice "washer" thin wall shim and its hard to cut round holes in thin shim stock.

So you have to measure and use shim stock (gasket material is not easily found in very thin sizes) and thicker sizes of gasket material is too compressible and you cant get a good reading. You will find that the usual suspects selling the gaskets and they are way way too thick at about .020" unless they changed their ways in the past few years.

So then after you got the all important end play set, use a small tube and tap the hub assy using the tube on the INNER race of the bearing. O-ring and use Hylomar, gasket more Hylo, Then the axle, then the drum and the two small drum retaining scruz, then the wheel and torque the wheel nuts to 40'# then lower the car. let the assy rest then without driving the car, retorque again to set the 'stack' and fully compress the o-ring.
 
/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif But I never heard or read it so detailed. Nice job.

These things need to go in the WiWi.
 
thanks Jerry - I think I'll pull it apart - redo it when I am about to reassemble the car
 
thanks.........contributions accepted.

I get a little anal on sub structures like running gear....I like to do things one tho and not spend time doing it again.

PS......Jack Laird.........I always thought your "location" of Niceville, Fl. was made up......UNTILL last night....on Jeopardy (TV) it's kids week...one of the kids was from NICEVILLE, FL. !!!!!
 
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