How would you compare two HST transmissions?

[94BULLITT]

Here's mine. I have seen some that looked more like turf tires.

View attachment 475524

I like those. IMO those are more aggressive than what they put on the larger grand l's.

 

[k0ua]

Why would you want too?

I wouldn't

 

[murphy1244]

I wouldn't

At least you get it.

 

[Retiredguy2]

Interesting thread....being a devoted green machine owner I have never really given much thought about comparing HST between brands. However if there were a significant difference between hydro fluid capacity between two roughly comparable horsepower and weight HST tractors I would tend to favor the model with the larger capacity for reasons of cooler running and possibly longer life between fluid/filter changes. Hydro pedal type preference (single or dual) would not matter to me in the slightest. Sorry if this is not what you want to read but fluid capacity is the only real factor that would influence me between brands,

 

[Wobblin-Goblin]

My 1643 HST is all mechanical and, like TSO's tractor, the pedal is mated with the throttle, so additional pressure gives you more throttle. It's a feature I like and consider it to be an improvement over regular hydro transmissions.

As far as Kubota's HST+, I have no experience with it, but it sounds like it adds yet another layer of improvement over an HST like mine. I'm not sure I'd spring for it vs. what I have now due to additional cost and unknown reliability over time, but it certainly sounds enticing.

FWIW, three years ago I tested out a JD 4520 with eHydro and it was extremely smooth and surprisingly quiet, more so in both categories than my MF HST.

 

[npalen]

I wonder if being able to switch in and out of FWA is as important as being able to switch gears on the go with a hydrostat. I've noticed, in doing quite a lot of loader work with my B9200, that it's a pain to shift in and out of FWA. An example would be picking up from a pile on dirt or whatever where the FWA traction is needed and then pulling out and turning on pavement where you don't want the FWA engaged.
I assume that most newer tractors allow shifting in and out of FWA on the go.

 

[Fallon]

Generally you can switch in & out of FWA (4wd) at any time, as long as tires aren't slipping. In fact it's often easier to do so while moving.

A cool feature on bigger machines is FWA automatically engaging when you hit the brakes, as otherwise there is only rear brakes when in 2wd.

 

[Retiredguy2]

Generally you can switch in & out of FWA (4wd) at any time, as long as tires aren't slipping. In fact it's often easier to do so while moving.

A cool feature on bigger machines is FWA automatically engaging when you hit the brakes, as otherwise there is only rear brakes when in 2wd.

That is news to me....but I have never quite understood why anyone actually needs brakes for anything but parking on a slope when you have a HST tractor...let off on the hydro pedal and the tractor basically stops dead. I have NEVER used the rear brakes of my 4410 for any slowing down or stopping purpose. EVER. Parking on a slope...yes.

 

[k0ua]

That is news to me....but I have never quite understood why anyone actually needs brakes for anything but parking on a slope when you have a HST tractor...let off on the hydro pedal and the tractor basically stops dead. I have NEVER used the rear brakes of my 4410 for any slowing down or stopping purpose. EVER. Parking on a slope...yes.

Here is an interesting and exciting phenomenon. If you go down a slippery hill traveling forwards for instance grass or gravel, and you have a load in your bucket, and depending on how heavily ballasted your tractor is in the rear, you will lose traction with the road surface with your rear tires. If you are in 4wd this will not occur because the surface tire patch contact area of the front tires will add to the total compression braking.

As you go down the hill forwards the normal weight shift occurs placing more weight on the front axle, and reducing weight on the front axle. This occurs any time you go down a hill forwards. Now if you have a load in the bucket, this load acts as a lever placing more weight on the front axle and less weight on the rear axle. The contact patch of the rear tires with the slippery road surface just gets lighter and less surface area.

The hydrostatic transmission acts as a brake if you start to let off of the forward pedal as you mention above.
So as you start down the hill under the conditions I have outlined, the rear tires lires lose their contact patch with the slippery road (gravel or grass or anything less than a rough high traction surface) and since the front tires in 2WD have no connection with the driveline, they cannot add to the braking action even though there is even more weight on them at this time, but they are freewheeling.

The end result is you "take a ride" of an out of control tractor sliding the rear tires and picking up speed as you fly down the hill, usually with one rear tire rotating backwards and with a total loss of speed control. It is now time to "throw out the anchor." If you have rear implement that will grab the road, lower it and lower the bucket to act as a friction brake to slow you down. Depending on what is at the bottom of the hill, you can either ride it out or go over the cliff or hit the tree or what ever is in your path, because the foot operated brakes nor the braking action of the hydrostat is going to save you.

If you haven't had this happen to you yet, That is a good thing. But if your slopes are steep enough, and slippery enough and your FEL is loaded, and your 3pt is a little light, AND your are in 2WD. IT WILL HAPPEN. And you will be on here telling us all about it.

What often happens is the operator will have the need to avoid some obstacle at the bottom of the hill and will turn the steering wheel, and that is when the tractor overturns. Or they hit the tree, or they go over an embankment.

Moral of the story, when descending hills, stay in 4WD (FWA), or descend the hill, rear wheels first (backward) if using a 2WD machine. Good luck, stay safe and happy tractoring.

 

[Fallon]

I was moving a horse panel on my forks. As it was only 100lbs or so I knew I didn't need any ballast on the back. Roll down the hill on the grass to lean it against the back of the barn. Got close to the barn & let off the go pedal... nothing happened, I kept going. Hit the brakes, nothing happened. No I have 2 pallet forks sized holes in the back of my barn & skid marks that aren't on the ground.

I'd have been fine if it was in 4wd or I had ballast on the 3pt, but I hadn't bothered as it was just a 100lbs panel...