Before I get into it I'll waste your time saying: I am an experienced mechanic, I know what I'm doing but I cannot get to the car until the weekend to see what exactly is wrong with it.
87 Rx7 Turbo II
Situation: Around 4am I had just finished rebuilding all of my calipers and installing new pads and slotted rotors. I bled the brakes yatta yatta I checked everything twice and it was good to go.

I backed out of the garage with 0 problems testing the brakes a number of times on the way out (both pedal and emergency brake) Finally I made it to the street and put it in first, as soon as the car started moving forwards I felt the back left (rear drivers side) wheel catch or hop or something. It felt like I had gone over a speed bump on that tire going pretty fast.

I did not hit a curb or anything, this was flat street.

I got out checked the tire, brakes were not dragging though pieces of something metal were on the ground. Large pieces with teeth like a gear, and many of them were built up behind my NEW rotor crammed against the dust pan.

Summary: The wheel won't turn, I got it dollied into my driveway so it is out of the street, something broke behind the rotor and it has teeth like a gear does.

I'll be able to get to the car on Friday to check it all out as of now I am back at school.


So: Any ideas on what broke? How it could have broke? Where to get a replacement?

 

The car have ABS? Only thing I can think of that has "gears" is the ABS rotor sensor.

 

I'm pretty sure it does not.