"Shifting gears" with a hydrostatic transmission

[JackJ]

Really two separate questions on transmission gearing.

I sometimes drive some steep hills on road with my BX1870. It's clear from my transmission temps (which I'm monitoring with an infrared thermometer) and the hydrostatic whine that this puts a considerable strain on the machine.

So question number 1: Is there any difference in load on the transmission when I'm going uphill at 3 mph in high range vs. 3 rpm in low range? I'll admit that I don't yet understand how an HST works, so maybe this will help me with the concepts. But intuitively, with the same engine RPM it seems like the mechanical advantage would be the same if the ground speed is the same.

Question 2: It's clear that the tractor needs to be at a complete stop when changing from low to high range or vice versa. But I frequently am unable to go from 2wd to 4wd when stopped--the lever won't move, yet it will move smoothly and with no grinding when the tractor is in motion. With no resistance and no grinding, I'm assuming this is safe to do. Am I right?

 

[85Hokie]

Really two separate questions on transmission gearing.

I sometimes drive some steep hills on road with my BX1870. It's clear from my transmission temps (which I'm monitoring with an infrared thermometer) and the hydrostatic whine that this puts a considerable strain on the machine.

So question number 1: Is there any difference in load on the transmission when I'm going uphill at 3 mph in high range vs. 3 rpm in low range? I'll admit that I don't yet understand how an HST works, so maybe this will help me with the concepts. But intuitively, with the same engine RPM it seems like the mechanical advantage would be the same if the ground speed is the same.

Question 2: It's clear that the tractor needs to be at a complete stop when changing from low to high range or vice versa. But I frequently am unable to go from 2wd to 4wd when stopped--the lever won't move, yet it will move smoothly and with no grinding when the tractor is in motion. With no resistance and no grinding, I'm assuming this is safe to do. Am I right?

ON the 4wd switching, place slight pressure on the pedal of the hst and then the 4wd will engage, forward or backwards........it needs to hit that sweet spot to engage.

On the high/low range, think of the day when you pedaled a bicycle - the gear ratio changed as the stress on your legs changed. THE hst is similar - fluid flow changes the "gears" - basically the low is pushing pulling , high is getting from one to the other place quicker.

The whine will go away ifn you change out the fluid to the S-UDT2.

 

[CaveCreekRay]

What Hokie Said...

4WD can be selected or deselected under way. The only limitation is if you are under a good load, it may be hard to get the handle to move out of 4WD. Unload the gear train by letting off the FWD pedal a little and that will unload the gearing enough to let the handle move.

Also, this handle has always been kind of tough to move on my machine. Hard 90 degree corners are tough on your tires and 4WD widens your turn radius slightly. I just finished over 300 trips to my back yard loaded with rock and to turn a 100 degree corner I would shift out of 4WD to make the corner and then put it back into 4WD to get over the concrete gate threshold. After moving the T-handle that many times, its much easier to select and de-select so give it time to wear in.

Range can only be changed while stopped.

I shift my range selector without using the clutch either sitting still or rolling ever so slightly. Slight movement helps the gears engage. Too much motion and you will feel the "lump-lump-lump" of the gears trying to mesh. If you hear a grinding sound, you are way too fast. You'll get the hang of it.

Ray

 

[flyidaho]

An old post, which verifies for me I am not the only one to find shifting my L3301 HST speed range selector easier with no clutch at all. This was a recent discovery for me, and I searched the site to see if any others had come to the same conclusion, cool.

 

[mikester]

Question 2: It's clear that the tractor needs to be at a complete stop when changing from low to high range or vice versa. But I frequently am unable to go from 2wd to 4wd when stopped--the lever won't move, yet it will move smoothly and with no grinding when the tractor is in motion. With no resistance and no grinding, I'm assuming this is safe to do. Am I right?

If you have a clutch, try using it when switching ranges. M59 manual recommends doing it and...it works!

 

[NoJacketRequired]

As my signature line attests, i have three B-series tractors. Each one shifts differently, wither that shifting be from 2wd to 4wd or HST range selection.

As earlier posts have mentioned, one just has to find the "sweet spot" and shift the way your tractor likes it.

My biggest beef is that if I'm wearing shorts the leg of the shorts always catches on the HST range shifter. I've ripped more shorts that way...

 

[Missouribound]

My biggest beef is that if I'm wearing shorts the leg of the shorts always catches on the HST range shifter. I've ripped more shorts that way...

I have a similar problem with my B2320
The FEL lever catches my shorts when I dismount.