I've got a 1980 JD 4240 that has worked flawlessly for me since I got it out of Kansas about 6 years ago. I bought it with 9000 hours on it, and the only thing it had ever done was pull a grain drill before I owned it.

I had some leftover native grass seed from an EQIP project I finished up earlier, so I was putting out the seed last night on a 12 acre place down the road from my house. When I finished up, I tried cutting my PTO off and the shaft kept spinning I could press my clutch in and come to a stop and my PTO would stop, but as soon as I let off the clutch it starts spinning again.

Is there a problem with my linkage on the PTO lever in the cab? Or does it have to do with my clutch valve not fully disengaging the PTO? Just trying to figure out where to start first on troubleshooting/diagnosis?

The tractor is equipped with a power shift transmission with 8 forward gears and 4 reverse gears if that makes any difference at all.

The main clutch should not be having any effect on the PTO clutch on this tractor. My guess would have been that your throw out bearing on the PTO clutch is gone, but the interaction thing has me stumped.

My brother is a John Deere mechanic. I'll see if he knows and report back

ETA, this was his response:

"Power shift trans are a pretty complicated animal.

Sounds like the PTO clutch has gone out and is always engaged until he put his foot on the clutch. You'd have to hook hydraulic gauges to it and check PTO pressures to see what the PTO is getting when it's disengaged to know for sure if it's in the hydraulic valve or the PTO clutch itself. Not much help but you gotta get pressure readings before you can condemn a clutch on those. "