Cub PTO grinds rather than engages

[riverbend]

Moving the PTO lever only causes a grinding noise. It is doing something inside because it doesn't grind all the time.

Is disassembling the PTO as straight forward as it appears in the manual ? Any chance of dropping the shift collar when pulling the PTO ?

 

[47fivewindow]

I am reading that the pto never actually gets in gear. It is usually the little pin in the shifter that moves the gear that locks the two shafts together is worn. You will need to pull the rear transmission cover to provide access to the shifter. Some here have welded drill bits to replace the pin, but they are not that expensive. Getting it back together is sometimes frustrating but eventually you will catch the pin in the groove of the gear and slide it back together.

 

[Jim Becker]

As 47 said, a worn shifter pin is usually the problem. Less likely potential causes could be worn splines in the shift collar and/or the two shafts. Another possibility is a worn pilot bushing in the back of the transmission shaft.

The shift collar has a setscrew that keeps it from sliding off the shaft. So you shouldn't loose it to the bottom of the transmission. To install, you will want to remove the shift lever guide so you can rotate the lever shaft during installation. You can remove the filler plug to see what you are doing during assembly. Some people loosen the collar setscrew so they can remove it from the shaft and place the collar on the transmission shaft. The PTO lever is moved to hold the collar in place during installation. Don't do that. However, if somebody has previously been in there and done that, the collar CAN fall off the PTO shaft while disassembling. To guard for that, start disassembly by removing the shift lever guide and rotate the shift lever forward as you remove the PTO.

 

[riverbend]

There was no set screw in the shift collar. Where it went, I don't know. I searched around in the grease and didn't find it. Hopefully it is caught somewhere and won't make trouble for the transmission.

The driveshaft looks more like a hexagon than a splined shaft from the back end. Looking through the filler hole, it does not seem so bad. The pln on the end of the lever is worn as much as it looks.

Somebody used the PTO a lot. The splines look like saw teeth. That's probably why this tractor came with a bucket of sickle teeth and guards.

I'm going to leave the shift collar out for now and put it back together. Replacing the lever and PTO shaft will come later. I'll get by with it not quite hitting the rated RPM.

 

[grandpa Love]

There was no set screw in the shift collar. Where it went, I don't know. I searched around in the grease and didn't find it. Hopefully it is caught somewhere and won't make trouble for the transmission.

The driveshaft looks more like a hexagon than a splined shaft from the back end. Looking through the filler hole, it does not seem so bad. The pln on the end of the lever is worn as much as it looks.
View attachment 157896

Somebody used the PTO a lot. The splines look like saw teeth. That's probably why this tractor came with a bucket of sickle teeth and guards.
View attachment 157897

I'm going to leave the shift collar out for now and put it back together. Replacing the lever and PTO shaft will come later. I'll get by with it not quite hitting the rated RPM.

I have a used pto assembly for a cub in the shop. If you are interested we ship parts all the time. Gimme a holler.

 

[Jim Becker]

I don't think I would leave the collar loose in there. It is fairly big and there isn't a lot of open space around the ring gear. You could try fishing around with a magnet. It isn't much of a job to drain the oil and take off the back cover to get access to wherever it landed. Who knows what else you may find in there.

 

[grandpa Love]

I don't think I would leave the collar loose in there. It is fairly big and there isn't a lot of open space around the ring gear. You could try fishing around with a magnet. It isn't much of a job to drain the oil and take off the back cover to get access to wherever it landed. Who knows what else you may find in there.

Did the collar fall off? Or the set screw?

 

[riverbend]

I did take the back cover off and pulled the shift collar out. I couldn't get my arm in far enough to reach it through the PTO hole. It was sitting on the bolt boss (?) to the right front of the differential. There was a lot of black sludge in there but the grease was still pretty clean since I changed it when I got the tractor home.

There was no set screw in the collar but the collar was still on the PTO shaft when I started. I knocked it off pulling the PTO out.