D6 5R 607 won’t shift

D6 5R won’t shift gears , I believe we had it shifting gears 8 years ago when the previous owner had it, and I have only ran it briefly since I’ve had it, and it no longer shifts between gears. I know it has the locking system connected to the main clutch lever , but I’m not sure what comes apart inside the housing to keep the lock from disengaging. I’ve been looking through the parts book but can’t figure out exactly where the problem would be.

Thanks in advance for any help.

I have D6 9u, same transmission different gears. Had been sitting 10 years, the rubber boot on top of shifter was mostly gone. Very rusty crusty, did not move. Started poring oil on it. Started tapping with hammer. Started moving acting like it would work. Found other problems with this tractor. and my health is not up to the work to finish the project. So not sure how successful my work was. But did put a new rubber boot on to keep water out.

I have another 9u I was using cutting a road on brushy hillside. Started jumping out of first gear. Removed the plate that the cam pushes locking pins on the right side of transmission. Found nothing that was a smoking gun. But cleaned everything. Used spray lube on the pins. Tapped with a hammer to make sure the springs pushing the pins all had good tension. Put it back together and gave no more trouble jumping out of gear. So I assumed a bit of grit hold up the lock pin that was locking the gears in place. But again just a guess from the improvement by nothing more than cleaning and inspection.

So can you move the shifter?

Is the rubber boot in good shape?

If the shifter is moving, I would take the locking mechanism off the side of transmission. Looking if the pins are moving or rusted in place. Maybe as simple as a pin has come out, and lock pins not releasing when the master clutch lever is moved.

To go any deeper like shift rails I believe the whole transmission needs to be removed from tractor. On a wet master clutch model the clutch needs to be removed to get transmission out. So you need the Service Man 's Reference book. Many places it just fits by fractions of an inch. So it saves your sanity to follow the book. With all the room in the world WHY, Oh WHY did Cat not make it a just a bit more spacious to get thing in and out.

The shifter boot is in good condition , the shift lever does move around a bit and I can hear things trying to move on the shift fork side so I would assume the shift lock is not releasing , it doesn’t look to bad to get the side cover off where the locks and shift forks are so that will probably be my next project to see what has gotten stuck or come apart in there.