HST: Rabbit versus Turtle

[tmc2318]

Whenever I'm using my tractor for tilling I will usually run my HST tranny in LOW (turtle) speed then shift up to HIGH (rabbit) speed to turn around. I am wondering if I show just run in HIGH all the time or will I be 'wasting' power or lugging as you would in a higher gear. This may seam obvious but it is not like gearing as the HST tranny is constantly-variable as I understand it.
To put it another way - If I'm tilling at say 0.5 MPH @ 2500 RPM in turtle speed does it matter if I am in rabbit speed with the same 0.5 MPH @ 2500 RPM? I always use my cruise and adjust accordingly to get the 0.5 MPH. It's obvious that I would have less power if I shifted the gearing from L to M but does it matter with the HST ranges as well? Should I be running in high or low for tilling to get maximum power to the tiller or does it matter if I am at the same speed?

 

[Muskrat84]

I am just a novice when it comes to tractors, but to me it would seem that you wouldn't have the torque needed to till in high range. I would also think the extra heat you are creating would not do your tractor any favors when it come to longevity. I could be wrong, that's just the way I perceive it.

 

[gotcha]

I am just a novice when it comes to tractors, but to me it would seem that you wouldn't have the torque needed to till in high range. I would also think the extra heat you are creating would not do your tractor any favors when it come to longevity. I could be wrong, that's just the way I perceive it.

I totally agree with Muskrat's answer. That is the reason they put a high, med, and low gears in tractors. Low for slow speed and TORQUE and high for speed and mostly speed alone.
The Gotcha Man

 

[DavidAubke]

There is a definite torque difference between high and low range. Low range is not just a way of limiting the total available speed.

There have been several times where I ran short of power before realizing I'd left it in Rabbit mode.

 

[DavidAubke]

After reading your question more carefully, I have to admit, I don't know the effect the range shifter has on the PTO. While the range only applies to the drive wheels, I have to assume that it's still akin to running in a high gear. Your engine is working harder than it needs to thereby lowering the total power available to the PTO.

 

[SouthernConservative]

When running any PTO implement - I always use L or turtle - I can control the speed with the amount of pressure on the HST - I NEVER use the H or Rabbit unless I am traveling the 2 miles to additional property - and even then I don't go "all out" on the HST - Let the tractor work in the correct range and you will be fine - tilling, shredder work, FEL work all should be in turtle.

If you have 4x4 use it only with FEL work and heavy pulling..

 

[art]

I'd run in the middle range and not be doing any range changes.

That is the plus of the three range transmission that you still have good power in the middle range as well as good ground speed.

Tillers don't require much pulling force for forward turning tines but even the reverse tine tillers won't drag a 3030 down.

 

[dodge man]

I think in theory, you could run in high range, be using less HST pedal and being running the "same gear ratio" overall. I think in practice, running in low gear gives you alot more control with the HST pedal and you will be less likely to be lugging the engine.

 

[J_J]

Is not the PTO speed based on the speed of the engine, and when tilling, you are supposed to run the PTO at 540? Therefore at the same engine rpm, you will have the same HP to the tiller, and the effect of changing speed range is to move forward a little slower or faster. Just depends on the quality of the tilled earth you want. One go round may be enough at slow speed, while cross tilling at med or high speed may give some good results. Rules are rules, but they can be broken. Is it worth changing transport speed to get around to the end of the row, and how do you do your rows, up and down , side by side, or do a field from the outside in, putting the tractor in a smooth turn at the end of the row. I see a lot of tractors doing a 90 degree turn, then a 270 turn to come back down the side of the previous row, and thought what a lot of lost motion. It's just time, I suppose.

 

[KeithInSpace]

Whenever I'm using my tractor for tilling I will usually run my HST tranny in LOW (turtle) speed then shift up to HIGH (rabbit) speed to turn around.

I probably wouldn't mess with that. I off-load stone off my trailer in Low, and there it stays UNLESS I'm driving the load another 200/300 feet across my yard, when the time saved by stopping and shifting the tranny is made up by my vastly swifter progress across the yard.

If I'm tilling at say 0.5 MPH @ 2500 RPM in turtle speed does it matter if I am in rabbit speed with the same 0.5 MPH @ 2500 RPM?

It probably does matter, especially if you're working against the implement. If you're in a 'no load' condition on the tractor, I don't think it'd make a hill of beans of difference, but when working against a load (reverse spinning tines of tiller), I think of it as holding a car with an automatic transmission against a hill using the gas...eventually things start heating up beyond the cooling capacity of the transmission.

My rule of thumb? If I'm performing a function that REQUIRES me to stay below the top speed of my low range, I stay in low range. Or if I'm performing a ground-engagement function that forces me to push the treadle down more simply to maintain a ground speed against growing resistance, I stay in low range.

When running any PTO implement - I always use L or turtle - I can control the speed with the amount of pressure on the HST - I NEVER use the H or Rabbit unless I am traveling the 2 miles to additional property - and even then I don't go "all out" on the HST - Let the tractor work in the correct range and you will be fine - tilling, shredder work, FEL work all should be in turtle.

If you have 4x4 use it only with FEL work and heavy pulling..

Wow...your name says it all...Conservative. Don't ever put the "treadle to the metal"? I actually think it is easier on the transmission to have the full benefit of fast flowing fluid. No fear should be had in putting the treadle to the floor.

And as far as PTO engagement only in low range...I have a Kubota PTO-driven impeller bagger and mow in high range...never had a problem with that.

And only using 4X4 in those particular circumstances? I have a spot in my yard that requires me to engage 4WD as I mow...a steep spot that happens to be slippery with clay and almost always wet. What about down a steep wet hill? Or travelling across a muddy, slopping parking field? All things I've done.

I just wouldn't generalize so much. The different functions on the tractor are to help out in vastly varying conditions. Otherwise, they'd call the "4WD" lever the "FEL and Ground Engagement" lever. Or have a sticker next to the PTO, "Only Engage with Drive Transmission in Low Range".

 

[radioman]

I find its easier to use turtle for better control and better quality with pedal tredle to metal instead of in rabbit and foot only pressed a little. It seems to whine a bit more in high when tilling and when my tiller hit a rock
(mine is forward till) IT might jerk me and i press the pedal more and i move forward more. Doesnt look smooth behind me. I find that I don't like trying to do exactly one row over to the next since it requires me to back up and move over a bit more to do the next row. ALthough using a HST helps but not the best way. I find its easier to when starting, start at the edge of garden or tilling area, when you need to turn around, just do a sweeping arc 3 rows over and go back. that way everytime you start going to the first tilled path, you go to the next row of the first tilled path then when going back to the next row you are already doing the 3 rows over. much more efficent. makes sense ? I realize it sounds like I'm rambling on but not sure how to explain it with out a pic.

 

[Danno1]

I find its easier to when starting, start at the edge of garden or tilling area, when you need to turn around, just do a sweeping arc 3 rows over and go back. that way everytime you start going to the first tilled path, you go to the next row of the first tilled path then when going back to the next row you are already doing the 3 rows over. much more efficent. makes sense ? I realize it sounds like I'm rambling on but not sure how to explain it with out a pic.

Zamboni pattern!

.

 

[LBrown59]

*If you have 4x4 use it only with FEL work and heavy pulling..

*Not a good idea in my estimation.

 

[SouthernConservative]

*Not a good idea in my estimation.

Using the 4x4 for driving around, would be silly - in regards to the question - using the 4x4 when needed would be correct - thus the 4x4 selection option. Certian tasks need to have the 4x4 others only 4x2 - each person has a choice on how they should use the tractor to get things done.

Although seeing that you post nonstop - it would indicate that you own every tractor you comment on...however I don't see any models other than the BX's.

Good Day

 

[VAMountains]

Using the 4x4 for driving around, would be silly

Why would it be silly so long as you're on grass, dirt or gravel? I've only taken mine out of 4wd twice, and that was just to avoid tearing up grass on turns.

 

[carpenter383]

Why would it be silly so long as you're on grass, dirt or gravel? I've only taken mine out of 4wd twice, and that was just to avoid tearing up grass on turns.

It puts unnecessary stress on the drivetrain and wears the front tires out faster especially in sharp turns (even on grass dirt or gravel) I run mine in 2wd most of the time and only use 4x4 when needed or when I anticipate needing it in a few feet.

 

[bpsooner]

Would the same apply to the Sync Transmission? Is it best to keep it in "Turtle" while working with the FEL?

 

[rdsaustintx]

Would the same apply to the Sync Transmission? Is it best to keep it in "Turtle" while working with the FEL?

Yes.

What is a sync transmission?

 

[Duffster]

Why would it be silly so long as you're on grass, dirt or gravel? I've only taken mine out of 4wd twice, and that was just to avoid tearing up grass on turns.

It puts unnecessary stress on the drivetrain and wears the front tires out faster especially in sharp turns (even on grass dirt or gravel) I run mine in 2wd most of the time and only use 4x4 when needed or when I anticipate needing it in a few feet.

Plus it burns more fuel

 

[bill1]

I have a B21 TLB and I've noticed that "turtle" range has much more power, but is sometimes "too slow" when using the FEL, so I hear what the original poster is saying. I mainly do FEL work in the middle gear, which allows me to have the power I need but also a little more speed for moving the load.

Although I can't claim technical knowledge, I'd have to agree with muskrat and Keith, it seems that there wouldn't be enough power to pull the tiller in high gear, so I would just run it in low gear. I don't have a problem with switching gears, if the tractor will do a better job in low, I'd do the work in low gear, and if it would be a "big" time saver to stop and switch gears to run "faster" over to the next row, I'd switch gears. Otherwise, I'd stay in low for the duration.

This may stray away from the original posters subject, but when I first got my B21, I would run in 4WD pretty much anytime I was off the pavement or on my "nicer" grass. After getting some experience with the unit, I've found that I can do most general work in 2WD and just engage the 4WD when I need it. I'd say the main reason is that I'm trying to save tire tread, lol. If/when I'm in an area or situation where I feel more comfortable in 4WD, I'll stop and slip it into 4WD....