My 8 3/4 is out of what?

Was it disassembled when you got it ? You may have mis-matched parts. We got a 8 3/4 that was complete but had the wrong axles that were too short. Didn't find that till we tried to drive the car.Just a thought.

It was disassembled yes. It is all assembled and seems fine but haven't drove it yet.

I will pull the axles out and get measurements for the axles & housing.