safe engine rpm "window" difference gear vs hydro

[TripleR]

I remember reading years ago, "Lugging an engine can't hurt it, over revving can." Is this no longer a valid statement? Can you harm a diesel engine by lugging it?

http://www.tractorbynet.com/forums/owning-operating/177801-lugging-diesel-engine.html

 

[heviduty]

Well, there you go. I have never had mine so slow that it runs rough like many of the posts in the link describe. At some point under 1000 rpm, the power just seems to die off and it quietens down, sort of like calming down. At that point I have no choice but to back off. Probably shouldn't let it get that slow. Thanks for the information. You learn something everyday if you pay attention.

 

[jenkinsph]

I run my tractors from about 1200 to 1800 rpm for most tasks, when working harder I speed them up. I don't find it necessary to run all pto implements at full speed either.

About that dealer saying you have to run a hydro at 540 pto speed hogwash, wonder if he even owns a tractor. There are lots of salesmen with little knowledge of the products they sell.

 

[madmax12]

I run my tractors from about 1200 to 1800 rpm for most tasks, when working harder I speed them up. I don't find it necessary to run all pto implements at full speed either.

About that dealer saying you have to run a hydro at 540 pto speed hogwash, wonder if he even owns a tractor. There are lots of salesmen with little knowledge of the products they sell.

That dealer actually got back to me, after I started this thread.

I had re-reviewed the operator's manual, at his suggestion. I left him a message saying the manual said nothing about a difference in rpm gear/hydro. He then reread the manual, and in humility, said what he had been taught years ago, may not be true after all.

He said I might have taught him something today.

I informed him that if I taught him anything about a tractor... it was purely by accident. :newhere:

This forum, and all you guys, ...amazing. Thanks for all of your input.

Hijack away, and let the learning continue! :thumbsup::drink::thumbsup:

 

[aczlan]

I run my tractors from about 1200 to 1800 rpm for most tasks, when working harder I speed them up. I don't find it necessary to run all pto implements at full speed either.

Agree. If I am running a mower (cutting hay or long grass) I will run at PTO RPMs, same with the baler, but otherwise, I run at whatever is needed (keeping above the "vibration zone" and not lugging).
For example, when tedding hay (with a basket style tedder), I like to run with the PTO between 300 and 400 RPMs and the L3830 in a relatively high gear (9th to 11th) to move through the hay quickly and reduce leaf loss.

About that dealer saying you have to run a hydro at 540 pto speed hogwash, wonder if he even owns a tractor. There are lots of salesmen with little knowledge of the products they sell.

Ayep. On our BX2660 it is almost painful to run at full throttle due to the hydro whine bouncing off of the roof of the cab.

Aaron Z

 

[texasjohn]

IMHO, the HST can take it. I run at RPM that is lowest needed to comfortably do the task at hand. "Comfortably" means considering forward speed, roughness of ride, safety, FEL/3PH responsiveness, PTO load/performance, etc. Should it bog down, I back off pedal and/or increase throttle. When I get in the seat, I typically do a multitude of different tasks and thus will adjust RPMs dozens of times in a half day's work.

The tractor and throttle are there to be used. I do.

 

[94BULLITT]

For example a small tractor like your max @ 2500rpm will suck .75 gal per hour operating at 2000 rpm's you me be down to .6 gph, so there is not that much of a noticeable difference or a big savings by operating at a lower rpm. That was just a example I don't really know what your fuel consumption is.

 

[SSdoxie]

There is no defined minimum operating RPM that I know of, each brand and model can be a little different. This is some risk to the HST if operating too low of RPM under load. The charge pump has to supply enough oil to replace oil lost through lubrication. The high the working/drive pressure in the HST, the more oil is pushed through the lubrication clearances regardless of RPM, so if charge pump is not spinning fast enough it could loose lubrication. An indicator of when charge volume/pressure is low is when the pedal feels sluggish. Personally, I run mine about 1500 at the lowest when puttsing around and 1800 using the loader. Most of the the time I'm at 2000 RPM or over.

 

[jenkinsph]

Something else I would add is that using the 4520 with Auto Throttle pretty much eliminates the need to even use the manual throttle in my grading work. About the only time I touch the manual throttle is when running the MX6 cutter or 673 tiller, all the landplane, boxblade and raking is done with the auto throttle.

On the 110tlb trying to do loader work with the throttle above 1800 results in the fel moving too rapidly to have much control of it, how fast I run will depend on how much and how great the distance is transporting material. I attribute this to the larger capacity hydraulic pumps on this model compared to a 3000 or 4000 series compact tractor.

 

[madmax12]

There is no defined minimum operating RPM that I know of, each brand and model can be a little different. This is some risk to the HST if operating too low of RPM under load. The charge pump has to supply enough oil to replace oil lost through lubrication. The high the working/drive pressure in the HST, the more oil is pushed through the lubrication clearances regardless of RPM, so if charge pump is not spinning fast enough it could loose lubrication. An indicator of when charge volume/pressure is low is when the pedal feels sluggish. Personally, I run mine about 1500 at the lowest when puttsing around and 1800 using the loader. Most of the the time I'm at 2000 RPM or over.

So, perhaps there is a slight important difference. Your description resembles the experienced dealers concern. He was very surprised to find no mention of this in operator manual.

Thank you for your very detailed explanation.