Stub axle to bearing running clearance.

[sparky_spit]

.... not to be confused with bearing running clearance, as in the other thread on here.

Last year I had a vertical link failure (see another very lengthy thread on here if interested) and quite quickly bought some Canley trunnionless uprights to replace them. As is normal with me, I buy things quickly and then take ages to fit them, so I've just got around to fitting them this week in preparation for this weekend's HCR.

About the same time as buying the new Canley uprights, I bought some more new stub axles from the "broken vert-link" supplier as part of the refund I got from them (they are not Canleys).  

I fitted one side okay but when I came to fit the other side the inner bearing would not slide onto the stub axle.  After some checking of other stub axles, other bearings, and finally measuring the diameter of the faulty one I found it was just under a thou oversized.  It does not sound much but it would not let the bearing fit.  Knowing from experience that when a stub axle has been fitted and torqued up to the correct figure, it is difficult to get it out again without damage, and not having another good one to hand, I spent an hour or so linishing the oversized one in-situ, with strips of 400 grit paper and WD40.  You can guess what a joyous experience that was.

The bearing now fits fine.  However, to my point. I have no idea what the correct diameter of the stub axle should be and whether there should be some clearance to allow the bearing to rotate on the stub axle.  I know that they do, and that they are supposed to.

Anybody know what the clearance should be?

As an aside, fitting the conversion is a doddle and has very much improved the steering feel and made the car more nimble in some way.  Or it just shows how bad the old links were that I'd put back on after the broken new one (and its pair) were sent back.

[esxefi]

a bit late now but you could have tried putting the link and stubaxle in the freezer and the bearing race in the oven.

you might have got enough clearance for it to go on more easily.

as for clearance none is best,ideally the race should require some light force to fit it.

1 thou is just too much o/size.

Friday afternoon part? :-/

[sparky_spit]

Thanks for the reply.  Good idea about using freezer/oven; I've done the big one-piece Austin Maxi wheel bearings like that, although you only get one chance to get it fully on properly before it contracts and locks solidly in place.

But....  I'd always assumed that the bearing must not be a tight fit on the axle and must be allowed a limited freedom of rotation?

[Pete Lewis]

skf bearing bores   spit herald

inner  1.0000  - 1.0006"

outer  0.6522  -  0.6250"


as for the stub...      hand push fit , as said they should rotate  quite easily on the stub to vary the impact wear  and dont need  a drag to remove them     so 'clearance '  is better than  tight

Pete

[sparky_spit]

Thanks Pete.  So, taking the inner as an example, the stub needs to be manufactured to slightly less than 1" to cater for both extremes of bearing bore tolerance.  The next time I get a chance to check them, after the HCR but before the 10CR, I'll measure them both to see what I've actually got.  I'd assume a clearance of at least 0.6 of a thou would be okay. When I had them apart yesterday I didn't note down the actual figures, just the difference between them. Never mind.

I suppose all this is academic when you have Shacktune spacers and shims fitted; the inner parts of both bearing must be tight up against the vertical link boss/shim/spacer/outer washer and nut.

[Nick Jones]

In the OE set up they can rotate, but there is no reason why they need to - that is what the bearing is for.  In fact this has the detrimental effect of allowing them to wear away the the stub axle (on the bottom) and eventually cause play that cannot be eliminated.  This seems to be worse if the bearings are slightly overtightened.

As you observe, if you have the Shacktune spacers fitted then both inner races are all clamped up together as a unit with the stub axle - which is an altogether more satisfactory arrangement.

Nick

[dazzer]

As said they shouldn't rotate as they do then wear away the stub axle. The spacers with tapered roller bearing where actually fitted in the early days. I had a 1960 AH 3000 with spacers but many people discarded them over the years as couldn't see the sense with tapered roller bearings.

[Pete Lewis]

spaced or cassette brg are a completely different kettle of fish to the aged design taper rollers found in so many older applications
these do need to have the outer cone fixed and the inner race rotatable  on its stub or casing
whether its a stub of 1" or a truck axle at 5" the inner rotates with the drag of the rotation ,and has to be free enough to adjust and control the end float.  and allow expansion when hot

   always has   always should  and always removable,

Pete