excessive wheel bearing shims?

[Hoghead]

My BJ8, phase 2 did not have the spacer between the wheel bearings so ones were ordered along with a shim kit and new bearings

I now need .091" of shims to achieve .001" of end float which seems like a lot of shims and more like a washer sized spacer

The bearing races are pressed home and the distance between the races is fixed, so I do not see how I could have made a mistake.
All the shims do is space out the outer bearing in order to give clearance.

I did fit a new inner bearing spacer at the same time, however all this does is locate the hub asembly on the spindle and does not affect the end float

Is this an abnormal number of shims?

 

[Bob_Spidell]

First, the shims are used to set proper preload for the bearings (yes, I'm being pedantic, but there's a difference between clearance and preload).

My experience, with both a BJ8 and a BN2, is that 0.030" of shims, give or take a couple thousandths, is typical.

The one thing you haven't checked is the bearings; if you still have the old ones check their thickness--esp. the inner races--against the new ones.

I don't think a large amount of shims is necessarily a problem, but something does seem amiss.

 

[Hoghead]

Bearings are new

Inner race:
Old = .468
New = .462

Outer race
Old = .475
New = .475

The old set up had no inter bearing spacers and hence no shims
End float was excessive on the R wheel and is what started all this. Unfortunatly I did not measure end float with the old set up.

Only .006 difference between the new and old races

 

[Bob_Spidell]

Sure sounds like the distance piece (inner spacer) is about 0.060" too short. I just packed/adjusted my front bearings a couple years ago so I (hopefully) won't be taking them out soon, but maybe someone has an original spacer on the bench and can get the length. Wouldn't be a bit surprised if the new ones--if not NOS--are a different length.

To check end float you need to lightly oil the bearings and races then assemble everything and torque the nut down quite a bit (up to 70ft-lbs) to seat the bearings; are you doing that?

 

[Randy Forbes]

You'll notice that shims are supplied in thicknesses of .003", .005", .010" & .030" to cover most possible combinations of required end-float.

In the course of owning some twenty (20) British cars (mostly MGBs, which use the identical front hub design) over a thirty-nine (39) year period, including working at a San Francisco sports car shop back when Healeys were not only daily driven, but when they were commonly seen as well, your "excessive" clearance doesn't throw out any red flags for me.

If it were me setting it up, I might remark to myself that, oh, that's a lot, but I certainly wouldn't lose any sleep over it.

The important thing is that you were able to obtain the specified clearance, and can move on.

The only concern with that many shims, is getting them all to go smoothly over the step in the stub-axle, but if you used 2) .030", 2) .010", 1) .005" & 2) .003" you're in like Flynn!

Tip: a thin smear of grease will keep the shims stuck together for easier placement, and I always place the thicker shims on the outsides of the stack/thinner shims in the middle.

 

[Hoghead]

New distance piece from Moss is 1.574. Does not look NOS and made in the UK

Bearings are oiled and torqued to 60 ft lbs with this .091 shim stack to yield .001 end float

 

[Bob_Spidell]

FWIW, McMaster-Carr has shims in a large range of thicknesses:

https://www.mcmaster.com/#standard-shims/=iox7qh

The 'peel away' shims look interesting (but they're not big enough).

IIRC, the spindle shims are 3/4" or 7/8" ID (but not sure).

 

[Hoghead]

Bought more shims but questioning if this washer thick shim stack is normal.
I would think that the tolerances were closer than that and wondering if I could have done something wrong, or if a problem with such a thick stack

Oddly enough with the old bearings and no inter bearing distance piece, the end float was not much more than now with .091 worth of shims which makes me question my procedure

 

[Bob_Spidell]

With no distance piece the preload on the bearings would have been solely determined by how torqued the end nut was. Without the distance piece--as in most American cars--you tighten the nut to set the bearings, then back off and tighten again until it 'feels right.' A 'trick' my father taught me is to torque the nut until you can just move the flatwasher under the nut with a little leverage from a screwdriver (with a slot on the nut lined up with the cotter hole).

Since you've checked the bearing thicknesses, the only other thing besides an incorrect distance piece I can think of is one or both of the bearing races has not been fully pressed home--did you change them? Are you having the same issue on both wheels?

+/- 0.030" seems to work in a lot of cases but, like Randy said if everything else is OK a thicker shim pack shouldn't hurt anything.

My money's on the distance piece; Moss shows 5 different part numbers for different cars--inc. 2 for early and later BJ8s--are you sure you got the correct one?

 

[Hoghead]

I have the correct BJ8 phase 2 distance piece

The race was changed with the bearing and both are fuly pressed home

I am at a loss and on to the other wheel this evening but good to hear from Randy that it is not a worry but I still wonder why

 

[Hoghead]

.063 on the other side

 

[bob hughes]

With no distance piece the preload on the bearings would have been solely determined by how torqued the end nut was. Without the distance piece--as in most American cars--you tighten the nut to set the bearings, then back off and tighten again until it 'feels right.'

A mechanic on this side of the pond has remarked that some British cars of that time did not have the distance piece and shims, and just relied upon the split pin to hold the nut.Hoever, I can see some benefit in using the distance piece and shims, at least the nut will be 'tight' and not just rely on the pin.




Bob