Are there any HST's that can shift while moving?

[CTyler]

Are there any HST\'s that can shift while moving?

Just curious of there are any HST trannys that will let you shift gears while moving? The HST is nice but there have been more than a few occasions where I needed to change to a lower gear. For example, its nice to run around 5-6mph in high at lower rpm vs reving the engine near pto speed in med. However high doesn't have enough power to go up some of the hills so you have to stop change gears and go again.

Sure would be nice to push the clutch while moving and change ranges. Tried double clutching and it didn't work. /forums/images/graemlins/frown.gif
Perhaps there is a secret I don't know about. /forums/images/graemlins/shocked.gif

 

[SkyPup]

Re: Are there any HST\'s that can shift while moving?

I am not aware of one, but it is one of the main faults with the HST tranny.

 

[RalphVa]

Re: Are there any HST\'s that can shift while moving?

I've shifted my 4010 HST while moving. It's sorta like shifting gears without a clutch. Can be done if you know when to do it. Main thing is to get the load off, like it's a cinch to shift to a higher range when going downhill initially. You could downshift to a lower range at the base of the hill if you go across the hill a little bit to get the load off the axle when shifting.

Ralph

 

[SWB]

Re: Are there any HST\'s that can shift while moving?

The Case/New Holland transmissions (at least mine on the DX35) have a low and high range for the HST and you have to stop to change. However, within each range, there is also a high and a low range which you can switch back and forth between as you travel without stopping. The manufacturer claims this is a four range HST transmission and I don't know if this is strictly true, but you can switch between two ranges without stopping.

 

[keeney]

Re: Are there any HST\'s that can shift while moving?

My JD 4100 can shift ranges while moving. I never really thought about it, so I don;t know if it was "under load" or not at the time, but it was never a problem.

- Rick

 

[MessickFarmEqu]

Re: Are there any HST\'s that can shift while moving?

The tranny of the CNH TC35-40-45 is what you are looking for. Its a 2x2 range tranny, there are buttons on the loader control that give you that extra boost you want from time to time.

 

[jinman]

Re: Are there any HST\'s that can shift while moving?

The Class III Boomer New Hollands (TC35/40/45DA HST "deluxe" models) all have a "rabbit-turtle" switch on the right fender and a duplicate switch on the joystick if you get the 16LA loader. This switch changes the swashplate angle in the HST's hydraulic motor between 9° and 15°. It's controlled by a solenoid and very reliable.

When you step on the HST pedal, you change the swashplate angle in the hydraulic pump, but the rabbit-turtle switch does it in the motor portion of the HST for a very dramatic and easy speed change. Approaching a pile of dirt with a loader and switching to turtle with the switch on the joystick has become so second-nature to me that I truly don't know if I could stand to be without that feature. /forums/images/graemlins/cool.gif

The High-Low gear range selection does require stopping. If you try to change that one while rolling, you will only grind gears. /forums/images/graemlins/tongue.gif

 

[CTyler]

Re: Are there any HST\'s that can shift while moving?

Sounds like the NH is a step up in that regard, sounds nice.

I've tried changing ranges while moving from med to high last night and it was easy. Pushed in the clutch and kept the hydro peddle pushed. However there was no going back no matter what the speed with the clutch pushed in. Didn't mess around with it to much, perhaps letting the clutch out and getting the speed right will do it. Hey...we made progress anyway. /forums/images/graemlins/grin.gif

I've had a couple stick shift vehicles in years past and used to shift them without the clutch a fair bit with out trouble. It would be nice if the ranges were synced on the tractor. How much cost would that add? Wouldn't think its much. I don't mean to my tractor but for Mfg's to add this into new models.

Another separate question...We did all the dirt work in prep for building our house. I drove a CAT paddle wheel scraper that drove like a manual/automatic tranny. No clutch and the peddle was a gas peddle and you shifted up/down on the fly. What kind of tranny is that? Poweshift or something? Not sure if you could go into reverse with out stopping but I wasn't going to find out. The CAT sheepfoot was the same way. I forget the numbers but think they were an 815 and a 613.

 

[slowzuki]

Re: Are there any HST\'s that can shift while moving?

The CAT was likely a powershift tranny with a torque convertor too. A lot of backhoes are set up like this. The torque convertor sure extends the life of trannys that drive into dirt piles all day.

 

[NHeuro]

Re: Are there any HST\'s that can shift while moving?

I had a tc 45 d and you can shift rabbit-turtle on the right side or on the joystick and this was very easy. The best system i've ever used in a hydro but the high-low range was impossible to shift this is normal