Playing with the spare set of hubs, housings, and stub axles in the mess I call my workshop, I notice the radial play of the hub on the stub axle diminishes as the hub fetches up against the ramps at the end of the grooves in the stub axle. 

I suppose I should assemble a unit minus the bearing housing and see if the hub comes up onto the ramps. But I can't be bothered pressing on, then off, the bearings.

Hey Stuart, did I push more members to Facebook?

:-)

Alistair

> On Jun 3, 2015, at 12:58 PM, David Beierl <dbeierl@ATTGLOBAL.NET> wrote:
> 
> At 01:02 PM 6/3/2015, OlRivrRat wrote:
>>        AnyOne care to discuss just what might cause the Spacer to
>> Wear Shorter ~
> 
> Whatever moves against another surface will wear, evenly or with one
> sacrificial to the other (paradixically, the harder surface tends to
> sacrifice to the softer).  I  don't see the spacer as being in any
> particular danger unless its composition is such that it moves and
> wears preferentially to everything else in the assembly, which could
> be.  Even so, I think that the splines getting beaten up on axle and
> hub will be the major issue, not longitudinal wear.  Ideally those
> splines would exist only as a safety backup, but whether or not that
> applies here impact loading on them has to be kept to a minimum so
> they don't beat each other out of shape. leading to an accelerating
> cycle of increasing clearances leading to increased impact loads.  It
> would be simpler if they were loaded only in one direction, but they
> have to handle decelerating and reverse-gear loads as well.
> 
> Yours,
> David