Kama TS-254 Shuttle Problem

astr · May 2, 2009

greg_g said:
Two questions:
Have you actually taken the shuttle shift plate cover off the housing yet?
and is your shuttle lever up near the steering wheel, or down by your knee?

I haven't had this happen to my TS354C yet (same shuttle as your 254), but I've had what you describe happen to my KM454. About once a year actually. Easy fix. At the bottom end of the shuttle lever is a finger. This finger fits into a fork that moves on a rail. The rail moves a fork that actually executes the F or R gear selection. When the lever jumps out of the fork, it will move back and forth freely - but the fork is not moving on the rail. Hence you're stuck in whichever direction you were going when the lever popped out of the rail.

If that's your problem, remove the cover. I suggest you take this opportunity to make a new cover gasket too. Then reinstall the cover after repositioning the lever tip into the fork. Tighten down the cover bolts. Don't know about your 254 - but my 454 has a set screw that controls the depth of the lever in the fork. If you find one, loosen it. Push down on the lever till you feel positive contact with the fork. Move the lever slightly fore and aft to make sure you're actually inside the fork. Tighten the set screw

//greg//

Yes, I have the cover off. The finger engages the shift fork fine. It moves the fork just fine. I have verified this by shifting into F, removing the cover and checking that the fork is all the way forward. I then put the cover back on, shift it into R, remove the cove and again verify that the fork is at the full rearward position. When I put it into the F position, everything works fine. When I put it into R ab=nd start to let out the clutch, the engine will stall as if the transmission is locked up.

greg_g · May 2, 2009

Ok, was just trying to eliminate the simple fixes first. Looks like you're back to Chips suspicions

//greg//

astr · May 11, 2009

I've gotten distracted by more pressing projects so this one has temporarily been put on the back burner. When I get back to it and diagnose the problem, I'll post up. Thanks for all the help and suggestions.

bluechip · May 12, 2009

On the shuttle shift KAMA, the reverse gears operate ahead of the transmission, so I am wondering if the engine stalls when the shuttle is in reverse and the main shifter is in neutral. wouldn't hurt to verify both High and low range behave the same. If non of this has an effect, I would use a long screw driver and, while in forward (engine off cover off obviously) try to spin teh reverse idler gear on its shaft to make sure it is not binding somehow. let us know when you have more details...

astr · Jul 15, 2013

Well, I finally got back to trying to solve my problem. Turned out to be a very simple. The bottom of the shuttle shift lever was a bit too long. With the case top bolted firmly down, it would not go past center as it would hit the shift rail. I should have noticed this but when I played with it before, I may have not had the cover bolts fully tightened so there was enough slop to allow full motion of the shift lever.

The final solution was to grind a few thousands of the bottom of the lever where it engages the shift fork. I've put about 5 hours on it since the fix and all is well. It only took me four years to address the problem but this is the first time I really needed to use the tractor.

greg_g · Jul 16, 2013

Curious. Do you have a decent gasket between the shift cover plate and the transmission housing? or is it just metal-on-metal? The OE paper/cork gaskets are prone to wet rot. Tighten them down in this condition, and you lose clearance. I replaced all mine with hand cut gaskets from a bulk roll of NAPA oil/gas resistant gasket material. It's thicker than OE, and doesn't suffer wet rot.

//greg//

astr · Jul 17, 2013

The gasket was in bad shape and rotted as you have found and it may have contributed to my problem. I eliminated the gasket and used RTV and therefore had to grind a bit more of the shift lever.

astr · Jul 24, 2013

Well, the problem is back, or more accurately, I didn't fix it the first time. Now, when I put it in reverse, it sometimes seems to lock up and stall the engine, other times it just goes forward. I also noticed that when the transmission is in gear and I let out the clutch a little, enough to operate the hydraulics/pto, the tractor goes forward. It is as though the two clutch disks were seized together. I'm beginning to think that it is a clutch problem, rather than a problem with the shuttle box. The symptoms are the same in both high and low ranges and both high and low ranges seem to work as expected as does the 2/4 wheel drive.

Tonight, I'll pull the cover off and try spinning the reverse idler gear as Chip has suggested earlier.

Any suggestion would be greatly appreciated as I am totally baffled.

astr · Jul 24, 2013

It gets even more bizarre. I went home and pulled the shuttle cover off to see what was going on inside. In reverse, the engine would stall when I let the clutch out. I put the shuttle in neutral and, as I let out the clutch, the tractor would try and move forward. After a couple of clutch cycles, it cease to try and go forward. Then I tried reverse again and all was well.

Does this make any sense? The shaft that connects to the front clutch disk (pto &hydraulics) passes straight through the shuttle box. The rear clutch disk connects to the outer shaft that is concentric to the inner pto/hydraulic shaft. However, the outer shaft is split somewhere in the shuttle box. When the shuttle box is in reverse, the outer shaft rotation is reversed as it exits the shuttle box so it is turning in the opposite direction of the pto/hydraulic shaft that passes through the outer shaft. If there is some sort of binding between the rear portion of the outer shaft and the inner pto shaft, it would explain why the engine would only stall in reverse when I let the clutch out. In forward, they both turn the same direction so binding would not be obvious. It would also explain why the tractor would try and go forward with the shuttle in neutral as the inner pto/hydraulic shaft would still try and the turn the outter shaft due to the binding between them.

I tried to make sense of the parts catalog but it really doesn't show what gear mates with what.

Does what I'm suggesting make any sense or am I totally off base?

EDIT: In my previous post, I stated "when I put it in reverse, it sometimes seems to lock up and stall the engine, other times it just goes forward". It is possible that when I thought that I was putting it in reverse and the tractor was still going forward, I may have only have put the shuttle box in neutral.

greg_g · Jul 25, 2013

Clutch discs swell a bit as they cool down. That's why yours creeps/grabs when cold, but not after the discs have warmed up some. A properly adjusted clutchpack operate the same, cold or hot. So before you wear your brain out speculating, you should adjust the clutchpack. Pretty sure the procedure is in the owner manual, as are the gap specs. My manuals went with the tractor when I sold it. I can offer guidance, but understand that you'll have to deal with fading memories.

//greg//