What is the value of 3 range HST vs. 2 range?

[chim]

I've had Kubotas with 2 and 3 range HST's. With the 2 range B7500 hydro, there were many times there was no really appropriate gear for mowing sloped areas. It bogged in HI and crept too slowly in LO. The L3200 with 3 ranges was a definite improvement. It mowed well in HI range on the flat and slight grades, and MED handled the slopes OK but it still wasn't wonderful.

On other tractors, with the little Ford 1210 (2 ranges) and a light RFM I can mow any grade around here in HI.

The L4240HSTC with the HST Plus trans and Auto Throttle is in a whole other class. Most mowing is done in MED or HI with the auto throttle bumped to make the rear PTO spin around 425 or so RPM's. That is often the sweet spot for a nice cut, but varies slightly due to different conditions. Then the hydro pedal is used for forward and reverse. The hydro pedal has a spot where further movement requires extra force, beyond which the ground speed and RPM's increase. For most non-mowing activity the Auto Throttle is at the minimum setting with the hydro pedal controlling RPM's / ground speed.

 

[Jstpssng]

I very rarely use high range. Even on the 1/4 mile road in front of my house there is just enough hill so that I don't use H.
I've been plowing my 300 foot driveway for 15 years using the bucket. I have a back blade but have never used it. In winter my winch is always on, and I don't want to take the time to switch out on every storm.

 

[ericm979]

I've also had both two and three range tractors. I keep the 3 range one in middle almost all of the time. High is totally useless for me, it's for flat roads which we don't have.
But with the 2 range machine, high was higher than the middle range on the 3 range machine. Which meant I was stopping and shifting to low range more often.

The 2 range machine required more range shifting than the 3 range one does.

 

[nbryan]

This ∆∆∆

 

[KennyG]

My guess is that there is a technical reason behind low HP tractors having two range hydros and it's not just cost. With an under 25 hp tractor, you aren't going to be able to design it for an 18 to 20 mph road speed. Therefore, no reason for the high range. If you've got a 30 HP tractor, you're going to want three ranges, but, as a low HP owner I've never felt a need for a third range.

As noted here, a lot of people with the smallest 3 range machines never use the high range. I use my high range for most things (mowing, plowing snow, etc) and low when I'm pushing the loader and don't shift that often.

 

[kwbretired]

I have a question. Why wouldn’t a single speed work instead of the 2 or 3 speed transmission. Thats what is on my John Deere lawn mower & works great.

 

[4570Man]

I have a question. Why wouldn’t a single speed work instead of the 2 or 3 speed transmission. Thats what is on my John Deere lawn mower & works great.

You’d have to gear it too low to have the low end grunt that you couldn’t move anywhere. There’s a reason single speed transmissions are limited to lawnmowers.

 

[Jstpssng]

I have a question. Why wouldn’t a single speed work instead of the 2 or 3 speed transmission. Thats what is on my John Deere lawn mower & works great.

I plow in low range, and back up in M. (250 feet.) On the rare occasion I'm on the tar road I run in Hi. One reason I don't use it on the road in front of my house is because my dog is running along beside me... he could keep up but I prefer not to run him that hard.
Plowing my driveway is when I really miss my old 275 with shuttle... 4 low for everything, and it went back and forth from F to R a lot more smoothly than changing ranges on my 3301.

 

[TBone]

Exactly!I run in medium range 90% of the time.

X2 except I run in medium range 98% of the time.

 

[KennyG]

I have a question. Why wouldn’t a single speed work instead of the 2 or 3 speed transmission. Thats what is on my John Deere lawn mower & works great.

There are practical limits to the speed range you can get with a hydro. A lawn tractor operating from 0 to 5 or 6 MPH can get along fine with one range. A small CUT with a range of 0 to 12 MPH will need two ranges and a larger, faster CUT will need 3 ranges. The alternative, of course, is to forget the hydro and go with a CVT (continuously variable transmission) but that apparently isn't cost effective at this time for small machines.