I bought a used Woods RD 60 from my local Deere dealership. The paint (Kubota orange) was faded to pink, but it was otherwise in great shape. I don't think that it was selling, because of the paint. I got a good deal on it, and have been running it for the past two years. I use it behind my 790.
Today, as I was backing up (while mowing), I noticed the gearbox stand (a plate that bolts between the main frame, guarding the main pulley and supporting the gearbox) would move. To be more precise, the back would rise up. It seemed to do it when the grass was thicker and it was mowing harder.
I shut it down, and took it to the barn. There are (4) 3/8" bolts that hold the stand in place- the front two were still intact, but the two rear bolts had sheared flush with the face of the threaded hole in the plate. I had to disassemble about half of the top side to get to the remainder of the bolts, and run them out. I've gotten everything put back to together minus the belt covers, and I'll run into town in the morning and get four new bolts (I'll go ahead and replace the two front ones).
It appears, based on the sheared bolts as well as the upward movement of the rear of the plate, that either the torque of increasing the RPM's, or the increased load translated through the belt to the main pulley, creates a substantial upward twist of the plate. I am very surprised that there is enough load to shear both bolts (the driver's side one had sheared a while back and was rusty, and the passenger side had just broken- the fracture was shiny).
Anybody else seen this happen? If you do run a Woods RD (mine is a Heritage), check those bolts.