Lo Boy 154 transmission won't engage

[Mechanic4101]

I acquired a very neglected Lo Boy 154 for fairly cheap. I managed to get the engine running pretty well with a little bit of care and sweat. We even managed to run it around the yard. But, it suddenly stopped working. At first, I thought the clutch, which was slipping, totally gave up. I just finished changing out the clutch, but the transmission will not engage any gear. I can feel the creeper gear grab when I engage and dis-engage it, but there is no reaction or feel going through gears 1 to 3 or reverse. The flywheel pin is still good to the trnsmission input shaft. How bad is this? Is there a shear pin or something that may have broken inside the transmission? Thanks.

[Steve Butram]

You may have bent shifter forks not allowing the gears to fully engage. It will require pulling the top of the transmission off to do an inspection

Do a forum search for bent shifter forks

[Gary Dotson]

A lot of 154 owners, here on the forum, have had issues with the bolt that pins the flywheel to the trans. input shaft. I assume that’s what you referred to as the pin, check it again and be certain that’s not the problem. Otherwise, the members who know these tractors much better than I do, will be along to assist. No, there is no pin or key in the trans to shear.

[outdoors4evr]

Gary has it nailed. There is a shear pin in the driveshaft that has given out. Punch out the old and put in a new.
Some people replace the shear pin with a hardened bolt. There isn't much room for extra threads sticking out so use a locknut and trim off the extra threads with a grinder, dremel, or hacksaw.

[john2189]

Could be the weld broke that holds the cup to the shifter

[SONNY]

is the creeper fully in or stuck in between h and l?

[Mechanic4101]

Thanks for the ideas. I plan on looking at it further this weekend.

The creeper feels like it is engaging into Hi and Lo. The gears also feel like they are also engaging.

After seeing a video on adding a creeper to a transmission, I think the spline adapter on the transmission input shaft is damaged. When I replaced the clutch, thinking that was the problem, I found the spline center of the friction disk almost completely worn out. There was very little metal left to form the splines and a ton of play. There is also wear on the spline end of the driveshaft, but it still looks serviceable.

I'm planning on pulling off the creeper unit to check the interface to the transmission. I'll report back when I get it done.

Thanks again.