I am in the middle of replacing the pads and rotors on my 2007
Boxster S
and I am running into a problem where as soon as I tighten the set screws on the rear rotors they lock up and can no longer turn. I have already backed off the parking brake adjustment as far as I can but still, as soon as the set screws are tightened the wheel becomes immovable even before I put the caliper back on. Any ideas on what I may be missing here?
So, by your description the rotor is set firmly and completely against the hub. Will it turn without the set screws in place? Not that one would, but everything could technically go back together without the set screws in place, they are there to hold the rotor in alignment with the holes in the hub so that the wheel, rotor, and hub are all in alignment when inserting the lug bolts.There are extra holes in the rotor and sometimes when replacing the rotor, it’s happened to me when not paying attention, it‘s possible to set the rotor back on the hub using the wrong set of holes to match the hub. Usually the holes where the set screws go are tapered to match the tapered head of the set screws. Double check, if that is not the case and you are using the right holes, then there is another problem that needs to be explored. But I always look for the simplest little error that can cause such an issue. Good luck, keep us posted.
Is the car in neutral? Once you tighten the set screw you will be turning the driveshaft as well.
Back off the parking brake adjusters on the rear brake assembly. Your old rotors were worn. New ones aren't. The brake shoes were adjusted for your old rotors - won't be right with new rotors. ALSO - clean off the center hub the rotors center on (odd name for it eh?) with a wire brush, then use a smear (not a lot) of antiseize around the inside of the rotor center hole (where it contacts the hub) - that way it will come off easily in the future. Also use a smear of antiseize on the screws that hold the rotor to the hub. Same thing.
Good luck - let us know how it goes.
Unless he has limited slip - being in neutral isn't required. The other side will turn the opposite direction on an open-diff if the input is locked.
Have you compared a new and old rotor side by side? Use an accurate tape or ruler to ensure that they are exactly the same dimensions. If you were provided a rotors from, say a 987, that may have a larger or smaller offset. When working with machined metal parts they might look the same, but it doesn't take much for fitment problems. I recall getting 66.6 versus 67.0 mm hub adapters for new
BMW
winter tires. What's .4 mm's? Well, the larger ones fit while there was no was to mount wheels using the smaller diameter hubs.
Very late update here, but the issue turned out to be a simple one: The rotors I was sent were not the correct ones. After many failed attempts I finally just boxed them back up and had them exchange them for me. The new set spun as expected after being tightened down. All in all, very frustrating while it was happening but glad to have the girl back on the road!
Glad it turned out to be something rather simple. It is good that you were within the exchange time window. I bought a set of rotors about 2 years ago just to have when I planned to do the brakes over winter. But I made sure that the parts I received were correct since it could be several months before I got around to it. I'd read of another owner getting the wrong parts shipped and having to eat the mistake because of the limited exchange window.
While sh*t can happen to any vendor, and even the best screw up once in a while - I'm curious who was selling the rotors, the brand of the rotor, and if there was any issue exchanging them?
