540c xl rear endbell clamp.

[Serum]

You are talking about the endbell; but do you mean the back or the front of the motor (front as the side where the shaft sticks out)

mine has got an M3 screw in the end-bell that sits on the back of the motor.

[zeropointbug]

Yeah, I had a frightening moment where the set screw (like Serum said) went too far in and got lodged in-between the end-bell and the motor coils. I had to swallow hard and give it a turn and HOPE that it would not damage the coil at first, luckily it didn't, but I put some thread lock on it. I'm not really using it, I just thread the end-bell on until it's good and tight. Hasn't come loose yet.

[Mightytaco]

Yeah, i was talking about the rear of the motor. I unscrewed it once to check it out, but wasnt sure how good that set screw kept it in place after repeted bashing.