Clutch adjustment? And hard shifting.

[joshuabardwell]

My tractor has a "hard shifting" issue. To shift gear ranges, all pressure must be relieved from the drive system. There are various techniques to relieve the pressure: reducing RPMs to near-idle; turning the wheels all the way left, then right again; pressing in the clutch and tapping the HST pedal both forward and back; and the last resort, which is raising the front wheels with the loader and moving forward an inch or so (only necessary in 4wd). This works every time, although it's pretty annoying.

Today, while pressing in the clutch and tapping the HST pedal, I noticed that the driveline was not as completely disconnected from the wheels as I would expect with a clutch pressed in. Pressing the HST pedal didn't exactly make the tractor jump up and go, but it definitely made the wheels start to turn a bit. I'm guessing the clutch cable has stretched and the clutch needs adjustment. What do you think?

The hard shifting issue probably isn't related to the clutch, as it has been present since I got the tractor, and the clutch definitely used to be totally free. Frankly, the hard shifting is the single most annoying thing about the tractor. It really bugs me. Is it normal for an HST?

 

[lilranch2001]

I hardly even think about shifting difficulties on mine

Usually a tap on something and it moves

It is never going to be as smooth as a car shifting

 

[pwright]

Can't say that I have any particular problems with shifting on mine. Sometimes I do have to let the clutch back out and roll forward/backward a bit but that's pretty much it. I don't have but 28 hours on mine so far so that may have something to do with it.

 

[SSdoxie]

You shouldn't have to adjust the clutch on an HST with low hours unless riding the clutch pedal. If there isn't more than 1" free play pedal movement it shoudl be OK. May have some rust bulid up in the disc causing it to hang. Remove the drain plug from bottom of the clutch housing to drain any water that may be in there, then push up against a tree or something stout and try slipping the clutch while in low range.

The OP manual says to press clutch as first step when shifting, but I have found that using the clutch is last resort to get it to shift.
1. Step hard on brakes to come to complete stop.
2. Try shifting speed range,
A. If it will not come out of current gear then step on clutch.
B. If it comes out into neutral but will not shift to next range, while holding pressure on the shift lever let out on brake and tap HST pedal if necessary.
I have never used steering wheel or raised fornt end off gorund to shift and seldom change engien RPM when shifting. These are not synchronized transmissions so you must come to complete stop and shift with no load on drive train, that is where applying brake first usually is all that is necessay.

 

[94BULLITT]

I don't think any hydro tractor will slide out of 1 range right into the next every time. You need to do what Dennis said in step B. Sounds like to me if you have to turn the wheels are get the wheels up with the fel have it "wound up" from steering too sharp in FWD.

 

[joshuabardwell]

Well, I just went and checked it out, and in my opinion, the clutch could have been a little loose. I'd say there was more than 1" of travel in the pedal before the clutch released. So I tightened it up until it had just a smidge of travel, but it wasn't riding. I also opened the clutch housing drain plug, but nothing came out. I started the tractor up and pressed the HST pedal with the clutch in, and the tractor didn't go anywhere. Current leading diagnosis is the clutch pedal was just a little sloppy and was not fully disengaging the clutch.

 

[philkk]

You shouldn't have to adjust the clutch on an HST with low hours unless riding the clutch pedal. If there isn't more than 1" free play pedal movement it shoudl be OK. May have some rust bulid up in the disc causing it to hang. Remove the drain plug from bottom of the clutch housing to drain any water that may be in there, then push up against a tree or something stout and try slipping the clutch while in low range.

The OP manual says to press clutch as first step when shifting, but I have found that using the clutch is last resort to get it to shift.
1. Step hard on brakes to come to complete stop.
2. Try shifting speed range,
A. If it will not come out of current gear then step on clutch.
B. If it comes out into neutral but will not shift to next range, while holding pressure on the shift lever let out on brake and tap HST pedal if necessary.
I have never used steering wheel or raised fornt end off gorund to shift and seldom change engien RPM when shifting. These are not synchronized transmissions so you must come to complete stop and shift with no load on drive train, that is where applying brake first usually is all that is necessay.

This is exactly what I do with mine. As for hard shifting with hst's, most other tractors have an independent pto so they don't have a clutch pedal and shifting is smoother. But having a live pto means more pto horsepower.

 

[joshuabardwell]

I just wanted to follow up and say that I have had very good results with Philkk's suggestion 2B. I stop the tractor, press the clutch, shift to neutral, and then if there is difficulty completing the shift, I gently continue to press on the shift lever while pushing the HST pedal lightly forward. This seems to relieve some kind of internal pressure and it goes into gear. Once the shift is complete, I release the clutch. It's interesting, because if I am on a hill, when I shift into neutral, the tractor doesn't move, and then when I press the HST pedal, the tractor starts to roll as if the HST was holding the tractor back even though the clutch was pressed. I don't really know how to make sense of that. If the clutch is pressed, the tractor should roll regardless of what the HST is doing, right?

 

[SSdoxie]

I just wanted to follow up and say that I have had very good results with Philkk's suggestion 2B. I stop the tractor, press the clutch, shift to neutral, and then if there is difficulty completing the shift, I gently continue to press on the shift lever while pushing the HST pedal lightly forward. This seems to relieve some kind of internal pressure and it goes into gear. Once the shift is complete, I release the clutch. It's interesting, because if I am on a hill, when I shift into neutral, the tractor doesn't move, and then when I press the HST pedal, the tractor starts to roll as if the HST was holding the tractor back even though the clutch was pressed. I don't really know how to make sense of that. If the clutch is pressed, the tractor should roll regardless of what the HST is doing, right?

The HST is always connected to the speed range transmision & differntial (direct connection through the motor. When you step on the clutch you disengage the engine from the HST, so the HST pump quits spinning but the HST motor is still engage to rear end. Don't know why it doesn't roll if range selector is in neutral (mine will) but when clutch is depressed there is still residual charge pressure in the HST applying equal pressure to both ports of the motor thus holding the motor from rotating. That residual charge pressure is what allow the motor to ratate and line up the gears when you tap the HST pedal with clutch disengaged.