IRS 11.65" Rotors Won't Sit Flat to Hub

Hi, TIA for your help. I'm assembling the rear brakes of a Type 65 Coupe complete kit with IRS rear end. The IRS brakes instructions say "Put the rotor on the spindle and hold it in place with a lug nut". Only problem is, although the rotor initially fits over the centre of the hub, it won't push back the last 1/8" and just rocks when I try to push it further. I've thought about trying to tighten it down with lug nuts, but that would be so brutal I don't think it would ever be possible to get it off again. It looks like I have the right parts, but why won't they go together?

Sometimes, the rotor has burrs on the inside diameter that mounts to the spindle. Also, sometimes the axle may have burrs too. Maybe just take a drum sander to smooth out both.

Henry

I have run into this as well. I used a drum sander
Like Henry said. Those rotors are a Saturn part.
Mike

Hi Henry, Many thanks for your response. There isn't a burr on the rotor, after closer investigation the problem appears to be with the hub. It's not really a burr - actually a slight step iin the hub diameter - I've measured the diameters carefully using a digital vernier and this is what I get:
Attachment 209606
Unfortunately, the hole in the rotor is 70.7mm diameter, so it goes over the first part of the hub, but won't go over the step to seat properly at the back of the hub. I can't see a way to easily grind off the hub (and it would be a pain to take it off the car at this stage) so I guess i'm going to have to find a way to machine out the hole in the rotor bell by half a millimetre. Not quite sure how I'm going to do that - going to need some kind of hone?

Hi Mike, many thanks for the reply and thanks for the info. As my reply to Henry, unfortunately it seems I have a bigger problem than de-burring.:(

call Factory five and let them know. I had the exact issue. It was a lot to try and grind down. You could also find someone with a lathe. It would take 2 seconds to fix.
Mike