Wheels won't go on new rotors
 

Got new C-Tek rotors for the rear of my 83 GSL. After installation, the wheels won't go on. I tried sanding the center hole of the wheel to make sure there was no corrosion holding it up, and tried giving it a tap with a 2x4 & hammer. Still won't go on. Anyone else have this issue? Did I get defective rotors?

I have had similiar issues in the past. I suspect it is a result of minor differences in manufacturing by different suppliers. Since it was apparently close enough so that you felt you could try forcing it on, I would suggest gently grinding down the offending part of the rotor. Unless you go really crazy, you won't affect the performance of the rotor.

Carl

A machinist could have you fixed up in less time that it takes to explain the lathe process to you. It's worth it for concentric mounting if you want to avoid weird noises from unfettered wheels. It's probably about $20 worth of effort, too. Anything worth doing is worth doing right...

YMMV, but in my opinion concentric mounting doesn't do anything, except make it easier to install the bolts (as opposed to having wheel studs that you can hang the wheel on while you install the nuts). There has to be a gap (not matter how small) so that the conical nuts (or bolt heads) can snug the wheel properly as the nuts tighten up in the "reverse" cone on the wheel.

As with most things on the internet, you can find many angry (and some less so) arguments for and against concentric mounting. I am not trying to start that here. Just adding my input based on the last 10 years of racing my 1st gen RX7 without any wheels that mount concentrically. The prior 10 years I used 13" Panasports or ARE's. The panasports were snug on the center hub, while the ARE's were not. The only ones that ever got stuck on the hub obviously were the panasports (or stock wheels if you want to countt the "roller" wheels).

Concentric mounting won't hurt a thing, I just don't think it is necessary for getting the wheel mounted correctly. If you feel better doing the concentric thing by all means go ahead.

Also probably worth keeping in mind that rear rotors on RockAuto are only $10-$20 each.

Carl

I find that many manufacturers offer rotors without any coating whatsoever, and they also offer rotors that have the center section powder coated. My guess is that they use the same cast and machined part for both applications, so there's no surprise that the rotors with the coated center section don't fit without some massaging. I have a series of sanding drums -- touch up the ID with the right size, and you'll be all set.

On a similar topic, do you guys have experience with GSL or -SE rotors and the spigot fit between the OD of the axle face and the rotor?

The fit between the axle and the rotor is designed to center the rotor on the axle. My Centric brand rotors seem a bit loose.

I had the same problem with Centric brake drums. I bought the cheapest brake drum listed on Rock Auto. What could go wrong? They went thump thump thump because they were out of round. The $30 I saved was spent on machining the brake drum's inside. Then they had trouble fitting on to the wheel rims. It was close enough to force it.

Cheap isn't good.
Good isn't cheap.

I just bought a new pair of rotors. It work