I contacted each of the tractorhouse companies that had used 4100s. 3 replied. I got the pto shaft for 350, about 1/2 the price of new. I would suggest comparing detailed measurements as one was the same overall length but not machined the same. The inside portion of the shaft was too long. Interesting where mine broke. Seems a gear or something else should have broken first. One of the bearings didn't turn smoothly. I don't know if that was the case before or after the shaft broke. I replaced it and the one adjoining on the other shaft. I was going to replace the other pto shaft bearing but felt the original was better than new. New had plastic to retain the ball bearings.