What is the clutch for on an HST tractor?

troverman

Well-known member

Equipment
MX6000 HSTC; 2020 Kubota Z421KW-54 zero turn mower
Jun 9, 2015
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NH
Just picked up my first Kubota. It is hydrostatic, but still has a clutch pedal. What's the point?

Thanks
 

Tallahassee Kubota Man

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M5140HD/LA1153/LandPride RCF2072/DirtDog disc/RakeMaster grapple/Caroni tiller
Just picked up my first Kubota. It is hydrostatic, but still has a clutch pedal. What's the point?

Thanks
On my L3010 HST (2001) you need the clutch to shift between Low Medium and High range. The other is for engaging the PTO switch. I don't switch in and out of 4 wheel drive often, but I always use the clutch when shifting. I may be using the clutch more than I need to, but am sure the PTO needs the clutch on my machine. Your new model may be different. My M5140 (2014) does not need the clutch to shift in and out of PTO.

Congrats on the new machine!
 
Last edited:

crickwaker

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B3300SU,BH77,LA504FEL
Dec 28, 2014
17
0
0
Kingsville,Oh
I've got a B series and agree with TKM. Clutch is used when shifting between ranges, 2-4 wheel drive, and for PTO on/off. Mine stays in 4 wheel most of the time unless I have to drive on pavement.
 

85Hokie

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BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
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Just picked up my first Kubota. It is hydrostatic, but still has a clutch pedal. What's the point?

Thanks
TKM and Crick both nailed it - for example - the newer style tractors have a electronic clutch - pull a knob or handle and the MMM or PTO engage. On older style ( I like these better ) you can allow the pto to catch up with the engine by slipping the clutch a bit rather than all at once.

I use the clutch as those other two said,

Moving from H to L and visa-versa
Engaging the PTO for the MMM or even the PTO
Starting the tractor!
And shifting in and out of 4WD.....

nice to have till you need to replace it !:p
 

troverman

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Equipment
MX6000 HSTC; 2020 Kubota Z421KW-54 zero turn mower
Jun 9, 2015
1,188
275
83
NH
OK guys, thanks for the info. I read the manual and it seems you are correct. However, it states the clutch should be pushed to start the tractor but it starts just fine without pressing the clutch pedal. The manual also says to start the tractor in the neutral position of the range select. This also is not a requirement. I suspect these are "for your safety" but not requirements. Only having the PTO engaged will prevent a startup.

While not moving, I have changed between 2WD and 4WD several times without issues. I also think you can change ranges when not moving without the clutch. My old Simplicity legacy had no clutch, but had a high / low range hydrostatic. Mine was 2WD, but some were 4WD. In either case, the range or 4WD change had to be made while not moving but there was no clutch. "Hydrostatic neutral" makes sure nothing is spinning.

By the way, how is 4WD engaged? As in, what is physically happening when you pull the lever?
 

DocGP

Member
Sep 17, 2014
117
6
18
SE TX
Mine won't start without the clutch, but that is about all I use it for. As long as the tractor is stopped, there is no difference in shifting between ranges. (MX 5100)

Doc
 

TripleR

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BX2200, BX2660, L5740 HSTC, M8540HDC and some other tractors and equipment
Sep 16, 2011
1,911
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38
SE Missouri
I don't know about the B Series, but I'm on my second GL and only use mine to start. I can tell no improvement in using the clutch to change ranges or engage/disengage 4WD.
 

Tire Biter

Active member

Equipment
B 2601 434 loader MMM, bunch of tractor stuff . Ford 4600
Jul 10, 2012
237
87
28
S.E. TN
On mine, I certainly wouldn't want to put the PTO in gear without disengaging the clutch unless I wanted to grind the tranny to junk.:D