JD 50 PTO issues

[TylerB]

Hello everybody. I am currently rebuilding the PTO clutch on my 1953 JD model 50. I do not have a JD service manual, just the IT manual. I assembled the PTO clutch and was trying to adjust it on the bench, the IT book tells you to adjust it so there is a 0.090" gap between the PTO brake plate and clutch cam disk. Upon doing so, the PTO clutch was nearly impossible to engage on the bench. But I got it engaged, and left it engaged over night (which I maybe shouldn't have done). When I came back, the snap ring groove in the shaft had broken off and the clutch plates were laying everywhere. Upon doing some other research online I learned the clearance on early models is supposed to be 0.060" ? (which the IT manual did not state). There was one shim under the brake plate, which I reinstalled upon assembly. I am wondering if anyone knows for certain if the .060 gap is correct, and how to know if I need to add more shims under the brake plate (because I assume this would lessen the force on the springs and snap ring). Thanks in advance