Wheel package & ?'s

[Charlie Guthrie]

Don't worry about centering rings....unless your torque gets low.
Wheel centering rings are primarily for locating the wheel before tightening
the lug nuts. After the lugs are properly torqued, it is only friction
between the face of the hub and the inner face of the wheel that locates the
wheel. Think about it. If the torque is correct, the faces of the two parts
are held together with very high clamping forces due to the torqueing of the
lugs. My old MG ran many track miles using alloy wheels from a Chevy Monza
without centering rings at all. The down side with not using centering rings
is that the cone taper of the lugs DOES NOT accurately center the wheel. The
fit between the threads of the lug and the nut allows some play, and the
centering action of the cone on the nut does not accurately center the wheel
(close, but easily 0.015" off centerline is possible as checked with a dial
indicator).

Now about plastic centering rings. Last year at Carolina Motorsports Park I
had the left front wheel lugs loosen (did I forget to re-torque between
runs?). The result was that the plastic centering ring was crushed and the
cone tapers in the wheel were wallowed out a bit (required re-cutting the
seats). Additionally, I had to pry the plastic rings off of other hubs
because they fused to the hub due to high brake temperatures. This bonding
to the hub is not a problem for street use, but it could be a track problem.
I had a set of aluminum rings made to fit the wheels, but in true engineer
fashion I made the ID hole for the hub a little snug by allowing a minimum
0.003" clearance. If you are having centering rings made, I suggest a little
more clearance because the least little grit or burr causes the ring to
stick. You can go with a very close fit between the ring and the wheel and
then use Locktite bearing retaining compound to lock them in place. I like
the idea of using Stainless for the rings because it is more resistant to
dings if you bang the wheel on the hub trying for a fast pit stop. If you
make centering rings try to leave a lip on the ring between the ring and the
wheel so that if you ever need to remove the ring you have a surface to get
a punch on so that you can drive out the ring.
Charlie Guthrie
I ar a Enginear