HST v.s. Gear

[Bohunk Farmer]

G'day. Virgin post here... am semi-virgin (whatevertheheckthatis) to the forum. Have enjoyed it so far.

K.. I have ended up (via some aggressive or reckless ... as my house spouse would claim... horse trading) with both a B-7100 D and a B-7100 HST. The HST is the one configured with the RC60-71B belly mower.

My plans are to use the Kubaby for mowing an acreage and for pushing snow (we are in Kansas Toto..).

So.. the Question of the day is: What is the pros/cons of the Gear drive v.s. the HST?

It appears that the guts of the two machines (cept for the belly PTO link on the HST) are bout the same. I was just wondering if there are any deep mechanical (and social/psycho/Tracto logical) differences tween the two versions of the 7100?

I have a small 4' disk and a 4' brush hog... and would like to do some food plot work with it as well. ( no loader involved.. have an old Farmall Super M to handle that). I do also have a 3-point 6 " finish mower (which I can run off the D version.. ) so I could run the mowing with either.

OK me harties... weigh in on this and help a greenhorn out!

Thanks

 

[Michael]

The advantages of a gear tractor that I have seen.

1. The transmission normally is for some folks supposedly beefier on a gear tractor

2. For what ever it is worth in steady state work (plowing a field or mowing a field with a brush cutter) a gear tractor is slightly more fuel efficient then the hydro tractor

3. The gear tractor is far more simple in design then a hydro.

4. The gear tractor tends to be a bit quieter then a hydro (you do not tend to get the whine that a hydro has)

5. They tend to have a higher road speed then a hydro

The disadvantages of a gear tractor

1. They are much harder to use in front end loader work if you are in a confine space.

2. They sometimes do not have the perfect gear for the work you are doing either to slow or to fast.

3. A gear tractor requires different maintenance then a hydro (they require adjustments of the clutch that a hydro do not have) and the same as a hydro on gear oil changes.

The advantages of a Hydro driven tractor

1. They are easier to operate, push the forward pedal and go at any speed that is required.

2. They are the cat meow on loader work, drive into the pile, pick it up and step on the reverse pedal and back up.

3. No clutch adjustments

4. Your wife can easily use the tractor as required and do what is needed.

5. Your teenage son or daughter might even use it to mow the grass.

6. Most have built in PTO brakes and a overrunning clutch is not required on most modern hydros.

7. Maintenance is easier, just change the fluid and filters as required.

The disadvantages are

1. I have not found any except they use a little more fuel then a gear tractor

 

[TopGear]

My opinion (and its only an opinion) is that gear machines tend to be a little bit more reliable for use with ground engaging implements - i.e. plows, tillers etc.
From the limited experience I have with hydro's they tend to suffer if worked hard. i.e. over heat, break things and tend to be very expensive to fix

But maybe this opinion is just because I compare things to my B6000 which has been abused, beaten, kicked, spat at and generally mis-used, yet it still keeps coming back for more Its like a pit bull!

Indeed hydro's are just so easy to operate its not funny and really come into there own for lawn mowing or loader work as mentioned. Maybe the newer hydro's have overcome any of the above issues.

Maybe some of the mechanics on this site who look after these for a living can give a more informed opinion. It would be interesting to here their thoughts on comparing say a B7100 with a B7100HST in terms of breakdowns and reliability. Both have been out there for a long time.

Anyway just a few thoughts.

Cheers John

 

[eserv]

I really like Kubota's hydrostat. It is a proper built piston type as opposed to the ball piston as used in the Eaton transmission that many others use. The main disadvantage the gear type B7100 has is lack of a live power take off. That is, when you want to stop forward or rearward motion you must push the clutch, this disengages the pto as well which can be a big problem of something like a snowblower is running off it! with the hydro you just return the pedal to neutral and the tractor stops leaving everything else still working.
Ed

 

[Ob1kubota]

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My opinion (and its only an opinion) is that gear machines tend to be a little bit more reliable for use with ground engaging implements - i.e. plows, tillers etc.
From the limited experience I have with hydro's they tend to suffer if worked hard. i.e. over heat, break things and tend to be very expensive to fix

Top Gear you're top notch with these statements. I'll take a good old GST any day over a HST even with heavy loader work because I own examples of both and I can find them gears without grinding them, I find myself declutching even with a Hydraulic shuttle just because its reflex with all the hours I have logged in the seat.

HST you bet for mowing! But hard digging you can't beat the good ole clutch and the torque it will create under full power. Ed makes a good point too, make sure your GST has the double clutch for live independent PTO at half petal.

Last but not least, clutch adjustment and maintenance is a whole lot less than buying SUDT and filters over the life cycle. These new ceramic type button clutches will last an HST with proper reset ( adjustment ). After you have figured out the procedure on a double live independ style, single dics are second nature.

 

[stuart]

A small point on shifting with a gear transmission, that I am sure others may have discovered.

I was in the habit of clutch in, brake on, shift, brake off, clutch out. I consistently had trouble getting it into the right gear - almost always had to shift to neutral, clutch out them back in, to get the gears moving. Then I realized I was making it more difficult. Except for on significant slopes, the tractor always stopped on its own with the clutch in. By bypassing the brakes, the transmission/drive line had just enough give to let me into the gear I wanted 90% of the time, rather than the 20% before.

 

[Bohunk Farmer]

Hey Thanks a 1,000,000 for all the feedback.

Just wanted to announce the winner... I decided to keep the HST!

After using it an afternoon with a dirt scrape... I ended up becoming one with the machine... and did REALLY like the convenience (OK,,, I am one lazy dude..) of the HST... and... I found that .. even with the turf tires.. (as long as we weren't in wet stuff) I had great traction and it pulled plenty good to fill up that scoop bucket to the brim+.

Thanks again for the comments. I continue to listen and learn.

 

[eserv]

Wise choice! I'd stick with the hst too. Keep good oil in it and change the filter as recommended and I doubt you"ll ever have any trouble with it. If you work in tight spots it"ll get you out of trouble lots of times to!
Ed

 

[Eric McCarthy]

If you plan to keep it for the long haul throw it away now because in a few years the HST will be worn out tired and no good. I've owned several commerical lawnmowers they were hydro drive and I had to constantly change and adjust them. The gear model has been a proven workhorse since the dawn of tractors. Look at how many Ford 8n's are still dragging plows and working on farms today. Gears do not tend to break, hydro line's can blow. They blow all the time on everything. It's just a rubber hose with massive about of fluids being forced threw. How much is it going to cost you to have pumps and line fixed when they break?

 

[eserv]

There are no high pressure lines on a kubota hydro to give trouble, and, in reality the hydro is simpler than a gear job ( Just a variable piston pump feeding oil to a fixed piston motor) The biggest disadvantage for me with the gear drive is the lack of a live pto. Implements like snow blowers are difficult to run with them. If you have a B7100 or early B7200 treat it with care though! you can't buy any repair parts for the hydro from Kubota all they supply now is a complete unit. We actually have very little trouble with the Kubota hydro.

 

[handyman]

eserv/ob1 let me jump in I as you know am a newby. Didnt know kubota didnt make any parts now for hydro which I have. I really am glad you hit on that. Bohunk farmer thanks for getting this discussion started. When I do anything with the 3 point hitch except mowing ( 4 ft boxblade. pond scoop,trailer hitch).I ALWAYS USE LOW RANGE. What parts do I need to keep in back of my mind to look for if ever needed. Would rather look ahead than wait until needed and cant find. I know this is a open question but what usually goes first? Mine is B7100 1983 model. If I ever sell it which i doubt (really like first tractor) I will let the extra part go to.Thanks handy

 

[eserv]

There are no parts available from Kubota Canada for the Hydro transmission on early "B's" . they do provide a new complete hydro unit but it is over $2000. The most common failure on the hydrostats that I see is water in the hydraulic fluid, freezing the charge pump, which then breaks. It isn't hard to change the charge pump but it isn't available separately. Most dealers are afraid to work on the hydros anyway so Kubota's decision to only supply complete units is probably sound. I modify the charge pump from another model tractor to repair these older units but it isn't a job for most mechanics ( I am a machinist as well and it requires some delicate machine work) If you keep your hydraulic oil clean I'm sure your Kubota hydrostat will wear out several engines.