I have a 1984 FXR, stock.
Can you tell me what the purpose is of the spacer (1) that resides in the wheel hub? Is this meant to put a pre-load on the wheel bearings?

Thanks for your help.
LE

 

The length of this spacer (or spacer and shims) determines how tight or loose the rollers are against the cones (outer races).

The axle end play adjustment process will determine the correct size spacer, or spacer and shims.

 

Thank you Dan.

 

Going to add my thoughts. Did not see all of Dan's when I started. Sorry, Dan. Your bike does not have sealed bearing. Yours are adjusted by the final shims that you install. There is an amazing amount of allowable tolerance in the looseness.

Item 1 is a standard so when all the other components are in play, there is an area for the shim stack.

In the new system of sealed bearings, that spacer allows the torque to go thru the inner race so axle torques. One bearing bottoms in the wheel hub. The other side does not. That way, there is no preload. You do not really want preload on ball bearings. They work best with just a gap that allows lubricant. Too tight and they squeeze it out. Now we are talking grease. Some applications can be preload that requires no shake and the lubricant is fluid.

I developed these pictures to help visualize and understand. They are not to scale. I just CAD them for a picture.
Go by your service manual to set bearings.





wheel taper bearing adjustment.doc

 

Man I know how tapered bearings work and your schematic makes no sense to me!!!!!!!!!!!!

 

Looking at the second picture, with the axle torqued thru the center is a set distance. Then with proper shims that only apply to the outer race, by adding or removing determines the running clearance or what can be called the lubrication clearance. Like I mentioned in my first text, Harleys' spec is .004 to .018 end play. To me, that is a lot. I would tend to fine-tune it if it were mine to the minimum.

I can only guess that for a mechanic trying to make a living and maybe not having all the shims would be a lot if time. Obviously, they work fine if set the Harleys' spec.

​​​​​​Also why I ask the first poster to set it and work to his manual.

1340 fxrt hopefully, my simple example has helped you. If not, PM me. I removed the two pictures of the sealed bearing wheel to hopefully eliminate confusion. Also my sketch does not show the so-called top hat stepped sleeve that sits on top of the shim. It is represented by what I call the bearing spacer.


There is an outfit on youtube called Grim Parts Co . Has a very good tube on setting this and shows shims. Not sure why unless their stuff is copyrighted but it will not work here if you attach it. Never see that before...

https://www.youtube.com/watch?v=Pm-20nCGmkY&t=572s&ab_channel=GrimPartsCo

https://www.youtube.com/watch?v=Pm-20nCGmkY&t=572s&ab_channel=GrimPartsCo

 

FWIW I have never heard of Shims in the hub spacer location... we have custom made spacers...and always have bought long ones when new, in order to turn to Correct length... to preload the Timkens nose to nose..shims and pieces under the Timken and the seal of course... seems a PITA...

 

Are you saying what I call the bearing spacer in my sketch 2 which is what mechanics call the top hat and the shims are on the wrong side of the inner bearing in my sketch?

 

Nope... I'm saying I have never used a shim... either side..against the OP's # 1, inner Spacer.. course.. I don't get the Bearing Spacer, shown Under the Tapered Timken Either.. all of my "inner spacers" bear directly on the tapered Timken..

 

That's because yours are cut to fit and don't require anything else.