Front caliper offset

[belling]

I'm installing new struts, rotors and calipers and the outside of the caliper is very close to the rotor. Everything spins clean so it's not in contact, just pretty close. The parts are:

Bilstein RSR struts
"A" calipers
477-405-083A-M359 Rotors (NLA? I bought them a couple of years ago)

I bought the rotors for the old 'M' calipers, are they different than 'A' rotors?

Jeff

[Joe Bob]

Looks like it fits. As long as it doesn't move you are fine....

[Bill Verburg]

Originally Posted by belling

I'm installing new struts, rotors and calipers and the outside of the caliper is very close to the rotor. Everything spins clean so it's not in contact, just pretty close. The parts are:

Bilstein RSR struts
"A" calipers
477-405-083A-M359 Rotors (NLA? I bought them a couple of years ago)

I bought the rotors for the old 'M' calipers, are they different than 'A' rotors?

Jeff

Either the caliper needs to be spaced out or the rotor in., you want the center of the rotor to be as close to the centerline of the caliper as possible.

front A and S and M rotors are all the same @20mm, 3.2 Carrera are 24mm. But all have the same o/s

[belling]

Unfortunately it's offset in the wrong direction, I can't correct it without cutting the strut or caliper.

[chrismorse]

Check the other side to see if the same problems exist.

My guess is that the bearing race is not seated fully, thus holding the rotor out.

Ask my how I know this one :-)
chris

While you are at it, you might as well put a dial indicator on the disc face to confirm acceptable run out

[belling]

It's the same in the other side.

Yeah I'll pull the hub off and see if anything is not seated, but I'm pretty sure it is.

[belling]

Looks like the spacer ring isn't quite fully seated. I bet that's the problem.

[Porboynz]

When adjusting the front hub bearings I do them up tight first then release and adjust for the slightest detectable movement to give room for any heat expansion.

[Walt Fricke]

If not the spacer ring, perhaps the inside outer race isn't fully in. Of course, if you didn't replace the bearings as part of this upgrade, then either of these suggestions is unlikely.

But this isn't an issue which could be caused by leaving too much play in the bearings.

Among other issues having the rotor not centered is the fact that you will not be able to get new pads in the narrow side.

At one point Porsche changed the offset in the rear. I have two good used rear rotors made for cars before the change which someday will find a home. But if Bill V says the fronts never changed, I believe him. Besides, I have a pair of '68 front hubs that get swapped around in my two track cars - I like to have a pair of hubs with rotors mounted in the trailer in case ones I am using get the big crack - makes changing things much quicker.