[Spridgets] wheel bearing question

David Lieb dbl at chicagolandmgclub.com
Wed Apr 16 06:36:11 MDT 2008


> So does the SILENCE mean that nobody out here has an answer to my question 
> or ?????  Surely I am not the only one that has encountered this problem.

Leo,
The silence means that, since you don't want to fart around with shims and 
you don't want to convert to tapered roller bearings, you didn't leave much 
for us to say. However, here is a dissertation from FR Millmore, another 
Spridgeter:

"They are angular contact ball bearings.
Not the same as rollers. Names matter.
They are to be preloaded, the correct amount. Like the book said. (Unipart 
book quoted)
The spacer is a selective match to the hub it came in. Manufacturing 
tolerances are the reason for the selection; after that there are no 
tolerances.
Bits mixed up must be similarly matched.
IF the spacer is such as to leave play in the correct bearings, then it 
should be shortened the requisite amount.
IF the spacer is such as to give excessive preload, then shims should be 
fitted to bring it right.
The preload is slight, on the order of .001-.002". I do not know the OE 
spec, but this will work fine and give no problem.
There should be NO play.
Play lets the bearings beat themselves to death, making more play.
Play locally overloads the bearing, as the entire load is on two balls at 
the top or bottom in each bearing, depending on what the loads are at the 
moment. This causes extreme loads in the cage, which causes them to break - 
the common failure mode for the original bearings. If the OE brass cage 
bearings are readjusted for preload after initial wear-in, they last 
forever.
Play knocks back the brake pads, giving lousy brakes.
Pay attention.

The easiest way to measure preload is to fit a shim on the spacer, and 
measure endfloat, then reassemble with correct or no shims.
EG; If with a .005 measuring shim there is .003-.004 endfloat with thin oil 
only on the bearings, you are good. Remove the shim, pack the bearings with 
grease, and reassemble.
If with an .010 shim there is .006 endfloat, fit a .002-.003 shim.
ETC.
Be very careful about tightening the nut. Excessive force to line up the 
split pin hole will collapse the spacer, leading to excessive preload. It is 
best to measure endfloat with the pin hole just a bit short of lined up - 
how much short depends on how thick the measuring shim is, and how much 
endfloat you have - finesse! One trick is to use shims on the small end of 
the spindle, line the splitpin hole up, mark the nut postion, do your 
measurements, then put the measuring shim between the bearing and the outer 
retaining washer. That keeps the stack height the same = no guessing." 


More information about the Spridgets mailing list