I have a tube frame GT car that uses March 87C Indycar centerlock uprights and hubs. I think I've mostly solved an issue I had at first with the centerlock wheel nuts coming loose, thanks to help here on the forum (thread here). I am still seeing evidence of some back and forth rotational movement on the rear wheels due to the braking and acceleration cycles, even with the wheel nuts holding their torque. One thing I've noticed is there appears to be a lightly textured material applied to the mating surface on the hub side. Maybe friction material to resist rotational movement?
See pics below. The first one shows the material on one of the front hubs (actually rotor hats) - see the dark circle in line with the drive/locating pins. It's pretty much intact on the front still. The second pic shows the rear where it's mostly worn off, presumably due to the repeated braking and acceleration cycles.
I'm wondering if I should look into re-applying the friction material to the rear mating surfaces. Anyone know what this stuff is? Plasma spray coating?
Thanks for any input!