Rethinking HST/ eHydro, Hauling, trailers

[charleyfarmall]

In the last 24 hours I have been rethinking my search for a small ag tractor using a geared transmission and avoiding hydrostatic drive. I have two hydrostatic tractors, the Ck27 and my simplicity lawn tractor. I love using them around the barn and house and in fact would not want to mow the lawn without HST.

For tilling vegetable rows, I find HST vs Gear a toss up. I have used both. Same for field prep with a tiller although mostly I have used a geared 12x12 tractor. Field mowing I use mostly a geared tractor because my land is very rolling and the HST in Mid range is a PITA. I do not like keeping my foot on the pedal, and with the cruise on, when it hits a hill you have to back off the HST. Load match would help here if it can be used simultaneously with cruise.

Raking and tedding ( teddering as my neighbor calls it) is the same on either and I would bet baling is too.

Obviously loader work around vehicles or loading and unloading pallets goes to HST. Piles of dirt and a power shuttle are fine, you use the foot throttle and all is good.

Where HST might actually be very helpful is cutting hay. As you approach corners you need to slow down, swing a little, stomp on the right brake, and turn. I usually cut my speed in half on corners by down shifting because the PTO needs to stay at 540. Sometimes, rather than sharp turn I to the cloverleaf turn just to avoid gear changes ( raise the mower and swing around then drop the mower as you start the 90 degree swath).

I had just about convinced myself that HST/ ehydro was perfect and convenient for the swiss army tractor on the farm when I realized there is one more task.

I need to haul trailers to the barn. Loaded trailers. It's going to rain, the trailer weighs 5-6000 pounds. So does the loaded tractor. Slight inclines ( I know what's ok and where not to go). I rely heavily on engine braking in this case. I know there is some braking with HST IF you are in the right range, but I have NO experience with this. Does anyone here pull loads with their HST and allow it to brake? I know that in the wrong range on some of the hills on my farm my Kioti will run away.

Makes me think gears may still work better.

 

[bigbull338]

i can only tell you what my MX5100 HST will do pulling a load.we use it to pull a 4 bale hay hauler plus 1 on the loader.an we have a pretty good hill to climb after we come out of the meadow.an the tractor does it just fine in med or low.an its pulling an hauling over 8000lbs.

 

[Grandad4]

We've done quite a bit of work on slopes because of a moderate grade trail on our property and have not noticed any tendency to "coast" or "freewheel" with our HST's.

One project required us to transport maybe 100 yards of crusher run down the trail using the FEL. We figured the tractor (Kubota L4610) + FEL + backhoe + payload had to be close to 10,000 lbs. The HST gave complete control at all times with no slippage or tendency to run away. Did not need to use brakes for stopping or controlling speed (although you'd definitely set them for parking!). Being able to control direction and speed without use of clutch is a big plus for HST in that kind of situation.

 

[JB4310]

I would say as others, that you would have more control with hydro. it's infinite right down to almost zero. I never touch my brake pedals on inclines, loaded etc with my E-Hydro. with gear tractor you would have to be all over the brakes on tasks like you mentioned.
I say down to near zero, cause if you let off on a steep hill it will creep a little, not dead stop.

The downhill control on a hydro is different than on a gear machine, it's not like engine braking, it's done inside the tranny, I don't know how it works but you are not using the engine, you wont hear/feel it trying to rev the engine. At least that's how it seems to me.

The only time I would want a gear machine would be if I did ground contact implement work like plowing, discing etc. all the time, and I have done very little of that work so not sure gear would be better anyway.

JB.

 

[Verticaltrx]

In a sense getting a HST trans to have proper engine braking is like with a gear trans. You have to be in the right gear (range with HST) for it to be effective. If you are in high range the load will over power the HST going down hill the same as it would on a gear tractor in too high of gear. While it's on a different scale than you are talking, I tow pretty heavy trailers (3000-3500lbs) with my little HST Kubota here in the mountains of VA and never have a problem. Generally if the hill is steep and I've got a heavy load I use Low range, sometimes Medium range and apply a little brake.

What type of hay mower do you use? This is a situation where HST could be nice as you mention, but also a tractor with power shift would work just as well (better IMO). I assume you are looking at smaller sub-50 hp tractors though so that might not be an option.

 

[dex3361]

I use my L4400HST on the hills and the HST will hold back very well from full pedal and just roll back to slow down to zero. The hold back is amazing. The HST is very safe on the hills. The only thing I have been warned about is if you shut the tractor down on a hill and do not set the brake the HST will creep forward turning the HST pump and when the oil is out of the pump it will supposedly freewheel(I have never seen this happen only heard it described and do not want to test it). If I were to buy today I would either buy the MX4700HST or the MX5100HST.

 

[oldnslo]

How HST trannies brake:

HST will brake when they see an over running load like going down hill by turning the motor into a pump and the pump now becomes a motor. (Same pricipal as used on electric cars where the wheel motors become generators during braking)

you can have controlled run aways under certain conditions.

1) If there are counterbalance valves in the circuit and they are set to low. I don't know if ant tractors have these or not.

2) Gear box or gear range increases/intensifies the torque to the pump and it then over speeds the drive engine same as a gear tranny. Rare but possible occurance.

3) System cross over relief valve pressure is exceeded. This will give the same results as the counter balances. This will be a some what controlled run away but it will still be a run away. Example: system reliefs set @ 5000 PSI and this equates to 30 HP input into the transmission from the engine. If the load created by the tractor and load going down hill generates more than 5000 PSI going into the pump from the motor it will start relieving this pressure and allow the hydraulic to spin faster than the pump i.e. run away. Note: The relief will still maintain the 5000 PSI and act as brake but the tranny itself will not prevent this run away condition.

The opposite of this is trying to climb a hill and the tranny stalls. Again you hit the system relief valves only now you are stationary trying to climb the hill and if more load is added you may start going back wards.

Long winded but I hope it helps people understand what is happening.

Roy

 

[JB4310]

How HST trannies brake:


you can have controlled run aways under certain conditions.


Long winded but I hope it helps people understand what is happening.

Roy

Good info,

I'll just ad there is another way to have a run away with hydro.
Don't try and make a range selection half hearted/ limp wristed on a slope,
or like me you may miss the range and hit neutral, now you are free wheeling down hill.

Since with hydro you very rarely need brakes, it is not instictive to use them. That brief moment before you remember you have brakes can be very exhilarating to say the least

JB.

 

[charleyfarmall]

Thanks for the replys. I am still on the fence as to which way to go. I do general farming as a second job. I do rows of vegetables and till and plant fields, bale hay etc. Thinking about growing wheat and oats in the future. I also keep draft horses. While my TN75 is used for big and comfortable jobs, having a second utility tractor for smaller jobs and assisting with hay chores is very helpful.

I mow with a 7' sickle and haybine. I know how to maintain and use them and can mow 5-6mph so I am not likely to change them out for convenience. They don't use much power. A big tractor with a powershift isn't really needed. I wish there was a smaller unit with it. The closest is the MF 1600 with the DynaQPS. I was quoted about $38K for 1660 cab/ loader for cash. Pretty darn attractive. I am not sure Deere can match that. The MF has a longer wheelbase and would be more comfortable, the Deere has a self leveling loader.

Unfortunately, none of the dealers around here have cabs so I can't tell what the Deere cab is like in the compact tractors. For the same money as a 4520 I could probably get the 5083E, although I don't need the weight or fuel consumption, and I lose the maneuverabilty around buildings which is one of the reasons I want a smaller tractor than the TN75.

 

[oldnslo]

Good info,

I'll just ad there is another way to have a run away with hydro.
Don't try and make a range selection half hearted/ limp wristed on a slope,
or like me you may miss the range and hit neutral, now you are free wheeling down hill.

JB.

Yup missed that one and it would be a true free wheel pucker factor of about 10...