Warped Hub/Rotor Assembly

[jlandry@domain.elided (John A. Landry)]

OK Gang, I think I fixed the spun outer bearing race in my 76 Traveler's hub.
I thought I'd pass some observations on to the rest of you in case it might be
helpful to someone.

As Darrel Kline mentioned, you definitely don't need to waste time with a
press for removing or installing a rotor to a hub.  A few well placed whacks
with a punch and hammer pop the studs right out and back in.

As Doug Rasmussen mentioned, a warped hub seems to be the part of the assembly
which is the culprit of excess rotor run-out.  Here's why I think this is
true...

I pulled off the hub/rotor assemblies from my parts Scout.  Both rotors were
very rusty, but luckily they both measured near 1.175" thick.  So there was
plenty of material left for turning.  Seeing how the rotors on my daily driver
are at the absolute minimum thickness, I decided not to swap rotors after all
and just go with a complete hub/rotor assembly from my parts Scout.  One of
these assemblies had a nice smooth rotor, but shot bearings and races due to
rust in spots.  The other had nice looking bearings and races but a grooved
rotor on one surface.  I selected the grooved rotor because I needed to good
bearings.

While looking for new inner hub seals, I found a local auto parts chain store
which would turn the rotor on Sunday (Al's Auto Supply for you WA residents).
It turns out it a good thing I decided to have the rotor turned, as it had
some *serious* run-out!  I made it clear to the mechanic to remove only enough
material to get rid of the rust and not the groove.  He wound up having to
remove about .020 just to eliminate the run-out.  On the rotor face that had
the groove, only half was removed because of the warp.  Upon seeing this at
the auto parts store, I was worried that the hub/rotor assembly was chucked up
onto the lathe incorrectly.  But once I got home, I dry assembled it to my
Traveler and checked the run-out with a dial indicator.  It measured only
.002" of run-out, so the mechanic did a good job.

Here's the part that verifies what Doug said... even though the rotor face was
now true, without measuring I could clearly see the run-out at the hub face as
I spun the assembly.  The warpage is plainly caused by the hub... not the
rotor.  So if I were to remove the rotor from the hub for any reason, it would
have to go back on *exactly* in the same position to keep the rotor face true.

Thanks to everyone for their comments and suggestions.

Happy holidays,

John L.
-------------------------------------------------------------------------- 
jlandry AT halcyon DOT com      |
Conservative Libertarian        |  Scout(R) the America others pass by
Life Member of the NRA          | in the Scout Traveler escape-machine.
WA Arms Collectors              |
Commercial Helicopter - Inst.   | 1976 Scout II Traveler "Patriot" model
http://www.halcyon.com/jlandry/ |     1977 Scout II Traveler (Parts)