Clutch Repair Kama 554

[3RRL]

Congrats getting her back together Rob. What a chore! Let's hope there is no "next time"! Great job and a great thread; thanks for sharing with the detailed posts and photos.

Remember earlier I advised making some alignment plumb marks down to the concrete and some height gauge blocks before the tractor was split? In hindsight, after you rejoined the two halves, do you think the alignment marks would have made the assembly any easier?
-Ray-

Hi Ray, thanks!
Yes, I remember what you said. The alignment marks and blocks would have made it easier for sure. It would have gotten us to the point of the dowel pin line up a lot faster I'll bet. I think the "rails" that are used in big shops are the way to go. I was told by more than one person that rails are used for lining up the two halves so the tractor slides together perfectly.

 

[3RRL]

Nice job as usaual Rob.

Having only used my HST tractor I am curious about the 2 stage clutch. What are the 2 stages and when do you use them?

Hi denman,
The 2 stage clutch is for the PTO and the main transmission.
On my tractor you have to put the PTO into gear to use it. That is done by depressing the clutch pedal all the way down to engage or disengage the PTO.
The main transmission is also worked through the same clutch pedal, but you only push the clutch half way down to engage or disengage it. That way if you're doing doing PTO work, say such as brush hogging, you can maneuver the tractor while the PTO is still running the brush hog. You can clutch through the gears with no effect on the PTO until you completely push the clutch pedal all the way down to the floor. Then it disengages the PTO.
Rob-

 

[greg_g]

Put from another perspective, the 2-stage clutch pack is two complete clutches in one housing. The design that permits this is the nested driveshaft. Specifically, it's a driveshaft within a driveshaft. Both pass through the clutchpack, but the inner shaft is only connected to the PTO friction disc. This is what eventually turns the PTO shaft in the back of the tractor. The outer shaft is connected only to the main drive friction disc which turns the transmission - which in turn propels the tractor.

When you push a 2-stage clutch pedal all the way to the stop, you've disengaged both clutches; the PTO quits turning, the tractor stops moving. Releasing the clutch to the halfway point engages the PTO, but the tractor isn't moving yet. The 2nd half of the upward travel of the clutch pedal is what does that. As Rob described, the reverse happens when you depress the clutch. By pushing the clutch pedal half way, you can stop the tractor. But the PTO shaft will still be turning. Pushing the pedal the 2nd half of its travel - all the way to the stop - then disengages the PTO.

//greg//

 

[3RRL]

The tractor is back together except the FEL.
I wanted to make sure it would work so I left the inspection window open. And it does work. I drove it back and forth in the shop a few feet each direction. Both PTO and main clutch work fine.
Did I tell you I'm going to paint the FEL before I put it back on?

One thing that's happening now ...
When I'm in neutral in the main transmission and the shuttle shifter is either in forward or reverse, it feels like it wants to go forward or reverse. It's like the way the PTO spins when in neutral, but you can stop it by your hand. It never did that before.

But when both the shuttle shifter is in neutral along with the main transmission in neutral, it doesn't do that at all, since the shuttle shifter box disconnects the entire gear drive system, so I think it's in the main transmission box. I can step on the brake and the tractor stops. The clutch completely disengages both main transmission and PTO when the pedal is depressed to the appropriate levels.
Anyway, the clutch works good. It's crisp.

Perhaps it has something to do with that I jammed it into gear a couple times when I had to get it into the barn and I had no clutch to disengage the trans? I probably screwed the gears up or bent a shifter fork? ...Doesn't feel or sound like that though... no grinding or anything like that.

I saw in the manual there should be .02 to .04mm clearance from the main shaft bearing to something done by "shims"? This is in the main transmission box. Anybody know what that is all about? Anyway, I think it's minor and I think I'll put the loader on (after I paint it) and work it a little to see if it disappears. I haven't taken the main transmission box cover off yet to check it out, I'll look in there to see I can see something obvious first.

I posted this in another forum and got some replies about it. It's probably a minor thing and Tommy thinks that it might straighten itself out after a little use. Larry reminded me that the Kama is now on a smooth flat concrete floor and the heavy gear oils are cold. No loader or boxblade on so the tractor is the lightest it's ever been. I had the tires inflated high so I could roll it easily for the split. It's most likely hydrostatic coupling forces (I hope) or a slight adjustment in the shifting forks that I never noticed before when it was loaded down and in the dirt.
Thought I'd throw this out there if anybody has had a similar occurrence?
Rob-

 

[greg_g]

One thing that's happening now ...

My 454 does that too, I consider it normal. Just as an otherwise disengaged PTO spline turns gently because of parasitic (hydrostatic) churning of gear oil, so does the main drive shaft when the tranny is in gear. I'm guessing that there was some otherwise negligible slippage in your main drive clutch before, that was remedied when you adjusted the stack height. And you're right, it's more noticeable when the gear oil is cold.

Another "diagnostic" I'd recommend, is hooking up a PTO-driven implement to make sure it stops completely when the PTO lever is disengaged.

Did you also shorten the front drive shaft and fabricate a spacer? or is that a project for another day?

//greg//

 

[denmansoft]

Thanks for the explanation guys. I thought it was something like that but my only experience is with car clutches and transmissions. I wonder if my tractor has that? I have H-N-L for the HST and H-N-L for the PTO. Shifting these or starting the engine is the only time I have to use the clutch at all. Probably just one clutch though.
I hope I don't have to do my tractor anytime soon!

 

[Bob Rooks]

I have H-N-L for the HST and H-N-L for the PTO. Shifting these or starting the engine is the only time I have to use the clutch at all. Probably just one clutch though.

I'm confused now. Somebody help please.
Does, or does not, "HST" stand for Hydro Static Transmission, and if so, why would there be a manual clutch? Hydrostatic transmissions by their very nature do not require a clutch.

 

[shvl73]

I'm confused now. Somebody help please.
Does, or does not, "HST" stand for Hydro Static Transmission, and if so, why would there be a manual clutch? Hydrostatic transmissions by their very nature do not require a clutch.

Many use it for the pto. On those, the steer brakes are on the same side as the hydro pedals, making them awkward to use. On tractors like mine, with a push button for the pto, the steer brakes are usually on the left, opposite from the hydro pedals, making them easy to use. The downside, some find the sudden pto activation on the push button style to be too harsh on sheer pins.

 

[greg_g]

push button for the pto

Electric clutch

//greg//

 

[denmansoft]

Bob Rooks:
On mine the clutch is used when shifting ranges on the PTO(540,off,960) or the HST. During engine start the clutch disconnects all the load from the engine. Once running you dont use it for forward/reverse or speed changes.
I was just wondering if mine has 2 clutches in there. probably not.