Forward to reverse while moving w hydro

TomIre · Jun 2, 2020

I have an imperfect understanding of transmission with a hydro drive. Basically once I've said swash plate - I'm done!
I was bush hogging a steep bit by backing up the hill then heading down, rinse and repeat.
Am I doing any damage by going directly to reverse while still moving forward slowly? Or, is that what hydro is designed for? First hydro drive tractor and just felt wrong somehow.

WranglerX · Jun 2, 2020

I don't know directly about HST but you are going to snap stress the differential(s) and universals and forward drive line if you are in 4WD.... I would really hate to take some teeth off a ring or pinion...

Once upon a time way back when, I was rolling backward in my car and dropped it into 1 st and let out the clutch.... To my surprise I snapped the ring gear carrier right between the ring gear and the spider gear shaft.... Don't want to do that again...

Dale

kthompson · Jun 3, 2020

Had a salesman tell me on his brand you could, Yanmar new transmission. Forgot what it is called. But what JD and Kubota have told me, don't. I would not want to make hard direction changes myself.

RalphVa · Jun 3, 2020

Don't listen to any of this. There aren't any gear clashes, etc. to contend with on HST. You can hit the reverse pedal while going forward and forward when going reverse. Nothing is going to clash with anything. It's just hydraulics.

Ralph

KennyG · Jun 3, 2020

Ralph is probably right that it's just hydraulics, fluid flow. However, you may increase the forces on the u-joints and drive shafts, which probably isn't good. My tractor stops almost immediately when I get off one pedal, so you really can't change direction while moving at any significant speed. I'd say don't worry about it but don't go out of your way to change direction at speed.

ptsg · Jun 3, 2020

Also, the OP mentioned "slowly" which is most likely just the tractor coasting during the time of changing from one pedal to another.

It's not that he will slam from forward to reverse in the highest gear at full speed.

TomIre · Jun 3, 2020

ptsg said:
Also, the OP mentioned "slowly" which is most likely just the tractor coasting during the time of changing from one pedal to another.

It's not that he will slam from forward to reverse in the highest gear at full speed.

Yes, that's correct. Simply creeping downhill with, essentially, foot off the forward pedal. Butt, instead of using brakes to come to a full stop I'm going directly to the reverse pedal. Even the way the pedals are arranged makes me think it's OK.

Jchonline · Jun 3, 2020

RalphVa said:
Don't listen to any of this. There aren't any gear clashes, etc. to contend with on HST. You can hit the reverse pedal while going forward and forward when going reverse. Nothing is going to clash with anything. It's just hydraulics.

Ralph

Ralph is correct. HST was designed for consistent direction changes in mind. My advice is to not slam the pedal down in the opposite direction on a hill, because you loose torque. With HST, the lighter you press on the pedal, the more torque you have.

oosik · Jun 3, 2020

My Kubota M6040 does not have HST - it's hydraulic shuttle shift. I've never been in such a hurry that, one way or the other, I can't wait until the tractor comes to a full/complete stop to change directions. Just too dam much money involved to be in that kind of a rush.