Transmission popping out of gear.

[Posco]

I was using the Cub to grade some gravel for a friend today and noticed it wanted to pop out of reverse gear. I was trying to feather out some fairly deep gravel by back-dragging it and the tractor kept popping out of reverse. I had the transmission rebuilt four or five years ago and I generally baby it when shifting gears. I had no issues with it moving forward, only in reverse. Any ideas?

[Slim140]

Broken shifter holder. Common problem.

Had one doing the same thing. Here’s an easy fix.

[Posco]

Thanks, Shane. Not a big can of worms to dig into? I've done a lot of work on the Cub myself but some of it I farm out.

[tst]

shift fork if that is your problem is not a big deal to fix, pull the trans cover off and look at the forks close to see if they are cracked/broken, make sure the bolt that holds them in place is tight also

[Posco]

shift fork if that is your problem is not a big deal to fix, pull the trans cover off and look at the forks close to see if they are cracked/broken, make sure the bolt that holds them in place is tight also

Thanks for the input, I appreciate it.

[punchofdeath]

My shift fork bolt was loose and caused it to pop out of reverse. Tightened and never happened again

[Glen]

Hi,
Put the trans in neutral before removing the cover, it should be in neutral to put the cover on again.

Below is a pic of under the transmission shifter cover, showing the 2 shifter forks. The pic is looking from the left side.
The cover might need a new gasket, TM Tractor has them.
If the inside of the trans looks dirty when you remove the cover, you could remove the drain plug, let the oil drain out, and wash the inside with some solvent and a brush.

The 2 holes at the ends of the oil trough, partly visible in the pic, need to be open so oil will run down to the bearings on the clutch shaft.

Check the shifter while it is off the trans, the ball on the bottom of the shaft should be round, if it is worn, it needs repair. If the shifter feels loose or worn, it probably needs some repair.
Below are pics from TM Tractor, of the shifter bottom. TM Tractor has a new shifter shaft, if needed.

[Posco]

Thanks for the help, guys. I'll take a peek tomorrow and see what's going on. I'll let you know what I find.

[Posco]

I couldn't find anything broken or loose which was a relief. The gear oil was milky so I changed that and buttoned it back up.

[Urbish]

Do you get a nice click when going into each gear? Could you see the reverse gear and whether or not it is overly worn?

[Posco]

Do you get a nice click when going into each gear? Could you see the reverse gear and whether or not it is overly worn?

I'll take another look. I had this transmission rebuilt four or five years ago and I typically baby it.

[Urbish]

While it is apart, use a screwdriver or something to slide the shifter forks back and forth into each position. When it clicks into each gear, you should see the corresponding gears lining up nicely. It's possible that when the trans was rebuilt, the wrong spacer was used in the wrong position on the output shaft making the reverse gears barely in mesh with each other. If that's the case, a little bit of wear over time would round the edges that are in contact and make it pop out of gear. Make sure both forks are back in the neutral position before reassembling.

[Posco]

Will do. Thanks.

[Scrivet]

While it's open you may want to dig around in the oil sling gutter and clean out the weep holes over the bearings. Looks like a lot of oil pooled in there. Should be a hole in the bottom of the gutter, at each end, next to where the center cover bolt holes are.

[Glen]

Hi,
Shift the shafts while the cover is off, like was said above, using a large screwdriver, or a bar.
The shafts should snap into each gear, if the reverse shaft doesn't snap in positively into reverse, something is worn and needs repair. Something is causing it to slip out of gear.

Each shaft has cuts, a spring, and a ball that lock it into 3 positions. If the cut is worn, or the spring weak, it can slip out of gear.
Put both shafts in neutral before putting the cover on.

Below are pics from TM Tractor of a shifting shaft and the cuts, and a spring and ball.