Kama TS-254 Shuttle Problem

[astr]

I was doing a bunch of chipping a while ago. After about 3 hours of operation, I could not back up the tractor. When I shifted the shuttle into reversea nd tried to release the clutch, it would stall the engine. Forward was no problem. It was as though, when I put the shuttle shift into reverse, the forward gear was also engage, locking up the shuttle box.

I took the top cover off but really couldn't see anything obvious, however, I did notice that the oil level appeared to be very low in the box, just enough to only cover the lower gears. The dipstick indicates a correct oil level. The dipstick is exactly the same as the one for the main transmission. Is it possible that I have the wrong dipstick in the shuttle box or is the oil level supposed to be that low?

Any suggestions as to the cause of my problem? I know that I'll probably have to split the tractor but I hate to do so only to find out that it wasn't necessary.

 

[greg_g]

Naw, don't split it yet. Mine was abused for 130 hours before I bought it. Lots of obvious loader work, which means the shuttle lever was working overtime too. As a result, the hole the roll pin goes through (where lever attaches) was egged out. Lots and lots of slop between F and R. Sometimes it wouldn't even engage one or the other. I drove out the roll pin and replaced it with a slightly oversized self-tapping screw. Instant improvement, and it's been working fine for the last 200 hours.

//greg//

 

[Diamondpilot]

I agree with Greg. Your problem seems to be incomplete engagement of the F/R gear or associated shuttle linkages. As for the gear oil you can add some but it will find a level. Many of us Jinma owners have made a mod to the cover and drilled and taped it to accept a plug with a piece of wire to act as a dip stick.

Chris

 

[Diamondpilot]

I agree with Greg. Your problem seems to be incomplete engagement of the F/R gear or associated shuttle linkages. As for the gear oil you can add some but it will find a level. Many of us Jinma owners have made a mod to the cover and drilled and taped it to accept a plug with a piece of wire to act as a dip stick. One other thing on Chinese Tractors you should check the oil level with the dipstick just resting on the threads, not threaded in. This will bring the oil level up a inch or so.

Chris

 

[astr]

Thanks for the responses. I will check the shifter pivot tomorrow when I get out to the tractor.

 

[Affordable]

If all else fails,call Chip at Artrac he sold the Kamas for several years and will help you as much as he can

Tommy
Affordable Tractor Sales
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[astr]

I checked the pivot on the F-R shift lever - it is nice and tight. Withe the shift cover on, whwn I move the shift lever to either position and then remove the cover, I can verify taht the shift fork is actually moved to the maximum position in whichever direction I moved the lever.

Any other suggestions? Anyone else experience anything similar?

 

[bluechip]

I wrote a long explanation about suspecting the reverse idler gear on its shaft but deleted it because it would not explain the stalling when in reverse. (unless the gear has wedged somehow). The problem I was going to explain is a snap ring that sometimes comes out of place allowing the bearing to slide out from under the reverse idler gear. The normal symptom is when backing, if you step on the clutch and let it out, it is no longer in reverse and will not reverse again until you put the shuttle lever in F or N and then re-engage it. Have you had that symptom at all?

There is also a bearing between the input and output shafts of the transmission, but if it was this bearing seazing, you could only run in 4th gear. any other gear the two shafts are turning at different speeds.

I wouls suspect something is jammed in the mid connection housing, perhaps the reverse idler gear is seized on its stub shaft. You will probably have to drain the oil down to see as these gears are low in the mid connection housing (remove shuttle/4wd lever cover to inspect).

 

[astr]

Thanks BlueChip. I have not been able to back it up at all since the problem occurred. This happened after a loooong session of running the chipper (i got the chipper from you a few years ago and it has been great). The F - R lever moves fine along with the shift fork taht it engages. I have all of the forward speed so the concentric shafts arn't seized. I'll drain the box and see if I can see anthing unusual in the bottom.

 

[greg_g]

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//

 

[astr]

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]

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

//greg//

 

[astr]

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]

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]

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]

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]

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]

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]

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]

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//