Hi, Low Med ranges when to use what?

[Charlton John]

Hi, Seeking more advise. My 2620 has 3 ranges hi, med, low. The manual does not reference much on what ranges should be used when. On my older SCUT I only had 2 ranges of speed. I know I should use low when doing heavy loader work or high when traveling on road etc... My couple questions are when is the proper time to use medium?

Also I was doing some box blading this past weekend. My barn is up at the top of my property closer to the house which requires me to go up a small hill to get there. Seeing since I have had my 2620 in the 25 hrs. I have put on it so far I dont think I had it in hi range so I put it in high and attempted to go up the hill to the barn. Although I did make it up the hill it seemed the tractor struggled to get up the hill w/ the box blade on the back and it also seemed to screech a little louder than normal like it was struggling to get up the hill. I was running the tractor around 2000 rpm's (not sure if this matters)

Is this normal the sound/struggle in high range going up the hill w/ the imnplement on the back or should I not use high for this purpose? Thanks again guys!

 

[Evil the Weasel]

I have tried mowing in M and H and prefer M. I keep the RPMs around 2K, and pretty much have the forward pedal fully depressed most of the time. I get a little of that high pitch sound in H but I don't have a heavy implement on the back to try and replicate your situation. I really don't like using H for mowing because the hydro pedal is too sensitive in that range. Using M for mowing does limit ground speed though. If my yard wasn't so darn bumpy I could mow more quickly because the mower deck doesn't seem to struggle even in high grass.

 

[AndyinIowa]

General rule of thumb - operate in the lowest range to get the job done. It reduces strain on the powertrain, and increases pump and motor life.

IowaAndy

 

[amigauser]

I tend to use high only for travel, medium for most work and low for heavy loader work. The nice thing about the 3 speed hydro is most stuff can be done in medium.

I am not sure that I agree to operate in the lowest range to get a job done? You can do pretty much every job operating in just low range but I wouldn't want to leave it there all the time.

 

[Charlton John]

Thanks guys, Yes I too have used mostly low and med. Can anyone elaborate on my question as far as the the straining sound and somewhat struggle I felt I noticed when going up this hill in Hi w/ the heavy box blade on the back. Would using med. in this situation help me get up this hill w/ less strain due to the implement on the back? Thanks

 

[MarkV]

The strain you hear in high range while pulling a load on grade is not unusual. With an HST tranny letting up on the control pedal will provide more torque and should help. New users find this against their natural thinking at first because we are so used to adding more pedal on our cars when we need more power. If decreasing pedal pressure does not help then you need to drop to a lower range.

One warning, do not change ranges while on a hill. There is a momentary lag between range shifts and the tractor will free wheel when it hits that lag. From personal experience I know that it can get going well beyond the capabilities of the brakes.

MarkV

 

[Charlton John]

Thanks Mark, So I am guessing by your comments that the lower the range the actual more power the tractor has?

 

[BrierPatch]

Correct. Low range gives you the most power, High range gives you the most speed with less power. The whinning you were hearing, did you have the pedal pushed all the way down or was it a really steep hill. I have run mine in high range shuttling FEL full of dirt up moderate hills and not had a problem and I am only running it about 1500 rpm. Hydrostats will loose power the more you push the pedal, or actually you are asking it to do more work/load, which is what MarkV was mentioning about letting up on the pedal. I like using the high range and low engine speed and 1/4 to 1/2 pedal for moderate speed across flat ground to moderate hills to shuttle the tractor or loads around, but not really doing any work.

 

[Charlton John]

jbrier, Thanks Yes I did have the pedal fully depressed. I did have the FEL on (empty) and the box blade on the back (not to the ground) and the hill is moderate. I guess when approaching this hill w/ any heavy load on the back (or in the FEL) I should keep it in med or low. Or I will try the pedal not fully depressed. Thanks

 

[smfcpacfp]

I have experimented with the different ranges, and I would agree amigauser. I pretty much use M. When I went to visit a neighbor I used H on the road. When I wanted to go really slow, I used Low, not so much for the power, but because I was doing a finishing grade and I wanted to take my time.

Another issue with mine is 4WD vs 2WD. With what I do I can't imagine why I would use 2WD (unless I was visiting a neighbor). Work wise, I thought maybe you would use 2WD while mowing. The same is true with the cruise control. I can't really see a use for it because I don't do much cruising. My driving is more like city driving, stoping and starting.

 

[Hoosier_Daddy]

I mow a steep hill in Mid w/4wD without a problem. I use low for serious loader work. I use high to get to the beer or if Bathroom #2 comes into mind.

Cruise Control may not be a needed Item but I wished I had it with the old boomerang on the BX2200 when dragging a blade or box around.

Now I have it on the B26 and I expect I will use it one of these days and be happy. Of course if I am running down the road to the Local Legion Post then Cruise seems like a nice thing to have.

Tom...

 

[lawn_king]

When i owned a B3030 i used mid range for the most part, high range was useless for anything other than transport.

 

[slan]

I had to play with mine for the first while until I got used to the hydro transmission. I agree with most that high range is only for travel in 2wd. There seems to be a lot of drive line whine if in 4wd and would probably add more wear.

My thoughts on the loading of a hydro trans is not to load the pump and motor up by using a higher range than needed. It is like lugging an engine up a hill rather than downshifting. It just puts more strain on the hydro motor at the lower RPM's. Maybe I am babying it a bit too much because I am still at that "new tractor phase".

As for the cruise control, I love it for mowing the fields and chain harrowing. With the new hydro it automatically reduces speed if it gets into the tough stuff or going up a hill. You don't have to vary the speed with the hydro pedal. Just make sure the response dial is set to quick response and you are away.

This is from a relatively new owner with just over 100 hours.

 

[AndyinIowa]

Here's an interesting formula that will get people to lower their transmission ranges:

If Medium range doubles your tractor speed, it also doubles the pressure in the transmission motor circuit to operate at the same tractor speed. For instance, if your tractor requires 1200psi to mow at 3mph in low, it will take about 2400psi to mow at 3mph in medium.

Now for the interesting part. If you double the average pressure your HST sees in the propel circuit, you reduce the life of the rotating kits by 8-fold!

A pump that has a 10,000 hour approximate life at 3000psi, will only last about 3000 hours at 3500psi. The key is that small changes in duty cycle greatly affect transmission life.

SO in summary, if low range gets the job done, leave it in low. If medium gets the job done, leave it in medium. Always keep the tractor in the lowest range to adequately do the job. Transmission whine = high pressure = lower life.

IowaAndy

 

[slan]

Thanks Andy, that was what I was trying to say but you explained it much better.

It drives me nuts watchng someone mow in too high of a range with minimal pedal and low engine rpm.
Should make mental note, "dont buy that one if it comes up used"

IMHO

 

[BrierPatch]

Here's an interesting formula that will get people to lower their transmission ranges:

If Medium range doubles your tractor speed, it also doubles the pressure in the transmission motor circuit to operate at the same tractor speed. For instance, if your tractor requires 1200psi to mow at 3mph in low, it will take about 2400psi to mow at 3mph in medium.

Now for the interesting part. If you double the average pressure your HST sees in the propel circuit, you reduce the life of the rotating kits by 8-fold!

A pump that has a 10,000 hour approximate life at 3000psi, will only last about 3000 hours at 3500psi. The key is that small changes in duty cycle greatly affect transmission life.

SO in summary, if low range gets the job done, leave it in low. If medium gets the job done, leave it in medium. Always keep the tractor in the lowest range to adequately do the job. Transmission whine = high pressure = lower life.

I see most of your logic. I can't quite wrap my mind around it entirely. Could you help me understand how the variable displacement part of the pump works into your equations. Flow, Heat, stroke etc. I am not used to looking a hydrostat as a pressure pump. Are these equations linear or are you keeping it simple? Most pumps have an operation curve and are designed to operate in a particular range. If I understand your equations correctly then I should always run my tractor in the lowest gear so the HST will have the lowest pressure and thus last the longest?

 

[AndyinIowa]

I see most of your logic. I can't quite wrap my mind around it entirely. Could you help me understand how the variable displacement part of the pump works into your equations. Flow, Heat, stroke etc. I am not used to looking a hydrostat as a pressure pump. Are these equations linear or are you keeping it simple? Most pumps have an operation curve and are designed to operate in a particular range. If I understand your equations correctly then I should always run my tractor in the lowest gear so the HST will have the lowest pressure and thus last the longest?

I'm talking only about kit life, which relies on calculations of the pressure fatigue equations for the cylinder block, pistons, and slippers.

The equations are linear for speed of the pump. If you transmit the same torque through a pump, doubling the speed that the pump is spinning will reduce the fatigue life of the kit by half.

For pressure, the equation is to the 8th power. Some manufacturers use other exponents (I've seen 5th power on several presentations). Regardless, the pressure component of a life calculation is considerably more important than speed.

You are correct that heat, contamination, and stroke of the pump also affect life, but in a different set of calculations. I'm only talking about fatigue life of the pump parts themselves.

An interesting final comment: Virtually all pump failures I've seen in the past 5 years are due to contamination or viscosity related issues. If you keep cool clean oil in a piston pump, it will run a long long LONG time. As soon as you throw dirt in the oil, all bets are off!

IowaAndy