I have a 2840 I recently purchased.
The pto spins at all times when the tractor is running. The pto engage lever doesnt stay up when you try to engage it. It just flops down to the deck. The linkage is all connected to the pto control valve.
While troubleshooting I noticed the the book says not to mix up the control valve springs if you go in there. Its obvious that the pto control valve has been tinkered with and now Im wondering in the springs were reversed, would this cause the symptoms described? It seems odd that the engage lever not staying in position (captured by a detention) could be the spring balance being off.

Anyone dared to enter the pto control valve?

Thanks for any constructive help.

The next items to hope that have not failed is the pressure line to the brake and the pressure line to the clutch .

[quote="CVPost-Tx Jim"](reply to post at 04:23:52 01/14/21) [/quote

2x4 worked and Im thrilled!

Welcome to YT
Have you attempted stopping spinning pto by CAREFULLY placing a 4 ft 2x4 between drawbar & pto shaft to determine if shaft will stop spinning?? It's possible that pto shift mechanism isn't in correct position on control piston. JD parts site removed the ability of public viewers to access parts specifications. The spring lengths may be published in JD 2840 tech manual(TM4336). Another possibility is that the pto clutch disks might be warped causing plate dragging