What use is the clutch with HST?

   / What use is the clutch with HST? #1  

Johnbro

Gold Member
Joined
Aug 1, 2008
Messages
375
Location
Western Washington
Tractor
2010 Kubota L4240
Coming from a geared tractor (L2250) with a two-way clutch (drive and pto), I'm clueless what good a clutch is on a HST-equipped tractor (2010 Grand L4240 with HST+).

1. Have to use for starting, but that seems a safety-only thing, not an operational requirement due to design

2. I use it to shift into a different speed range (H-M-L) but not sure if that's necessary.

3. Seem some recent posts about using it to engage the PTO but unless I'm mistaken it has nothing to do with the PTO activation, since that's all hydraulic/computerized.

Help me out here. How do you HST drivers use your clutch?
 
   / What use is the clutch with HST? #2  
There are some not too old threads on this and I don't know if the question was ever answered as not all HST tractor have a clutch.

As to your questions:

1. My guess also.

2. I don't usually use mine to change ranges or engage 4WD. I discussed this with the dealer when I bought my tractor as well as communicated with other TBN members.

3. I have used the clutch prior to engaging my PTO, but don't usually do so any more. I really don't see any advantage to doing it as per the manual.

I essentially see the clutch on my L5030 as just something else to trip over. As always, I am open to information that proves otherwise.
 
   / What use is the clutch with HST? #3  
I am by no means an expert, but perhaps the safety thing is the key.

Unlike a car, there is no Park on a HST tractor. So, without a clutch you would always have to be sure to start in nuetral or you could be in for a suprise.

MoKelly
 
   / What use is the clutch with HST? #4  
Interesting question. My old B8200HSTD had a clutch. Used it to start the engine, change ranges, and engage the PTO. It was an '85, so it did not have the fancier PTO's of today. At a stop, with the HST treadle in the "neutral" position, I could change ranges without the clutch.

My NH TC40D that replaced it, is about '03. It is HST; it does not have a clutch pedal.
 
   / What use is the clutch with HST? #5  
All of these newer tractors have safety switches to prevent that. We must be protected from ourselves!

I am by no means an expert, but perhaps the safety thing is the key.

Unlike a car, there is no Park on a HST tractor. So, without a clutch you would always have to be sure to start in nuetral or you could be in for a suprise.

MoKelly
 
   / What use is the clutch with HST? #6  
Different models vary, no doubt, but on my B2320, I must use the clutch to shift ranges, or it'll grind if I forget.

I also use it with PTO changes and 4x4. Although, I think I need to use it only for one of them, but cannot remember which.:D:D
 
   / What use is the clutch with HST? #7  
For all the different people as well as their driving habits it's hard to tell what to use some of the different options we have today.

It will work to stopping the tractor if applied properly as well as to assist range changes.
 
   / What use is the clutch with HST? #8  
I use it frequently when using a post hole auger or even a flail mower. Its a quick and fast way to disengage the PTO. It is also a nice way to slowly engage a large load PTO attachment like a flail or rotary mower. Other then PTO uses, I don't use it except to start the engine because of the interconnect with the start relay.
 
   / What use is the clutch with HST? #9  
Also when starting you are not trying to turn the transmission.
 
   / What use is the clutch with HST? #10  
Noticed something new the other day about my clutchless JD 3032E. Parked uphill on a sloped concrete driveway in Low range and got off (I usually park in Low range and leave it in "gear" when I'm off it, don't always use the parking brake because I didn't think it would move in low gear with the engine off, just like a stick shift truck. Plus, 99% of the time I park on level or nearly level ground. But, as I now know, it WILL move. I heard a funny quiet little noise and looked back, and the tractor was very slowly inching backwards one quiet little "hiccup" at a time. I'm assuming the weight on the downslope was turning the engine crank via the HST, and overcoming the compression one piston at a time. It was weird to watch, moved about half an inch each time it happened.

I jumped back on and set the parking brake, which I will remember to use all the time now. Lesson learned.
 
 
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