PTO RPM??

Anonymous Poster · Mar 20, 2003

It is difficult to transmit more than 85 hp through a normal 540 pto shaft (Case-IH uses some very exotic metals to get up to 150 hp but it costs money!). So, for big tractors 1000 rpm was developed to supply more power to pto equipment. I realize this does not apply to compacts, but that is the standard for big farm equipment.

For compact tractors, all standard rear pto equipment will be 540 rpm. If your tractor offers different rear pto speeds, it may have non-standard equipment available to use those speeds. But 'normal' equipment does not use anything but 540 rpm.

It can be handy to run the tractor at 1/2 throttle and run a low-power device with the 1000 rpm pto, but forgetting & over-reving the device can blow things apart.

In short, all a tractor of less that 85 hp needs is a rear 540 pto.

(Is the Century a Chineese tractor? Can't remember, but I'd watch what I was getting if it is. I'm mostly color blind, but don't think that country has it's tractor production lines up to grade yet.)

--->Paul

Bird · Mar 20, 2003

Right, Paul. One of my neighbors who was using an 85hp Oliver was once bemoaning the fact that he couldn't borrow some of his brother's implements because the brother had a much bigger tractor and the implements he would like to have borrowed required the 1000 rpm PTO and the Oliver only had the 540.

chrisjbell · Mar 20, 2003

<font color="blue"> run a rear mower at 1000rpm and amazing things can happen </font>

OK, this got an "out loud laugh" from me... You must share what kinds of things can go on. I'm sure they aren't especially pretty, though /forums/images/graemlins/ooo.gif.

rockyridgefarm · Mar 20, 2003

Our Yanmar had the 1000rpm setting, and just the noises the Bush Hog made when in that speed was enought to scare the bejeevers out of you...

Basically, it is running things a twice its rated rate. You sure don't want to experiment on something of that mass like that...

MDNick · Mar 20, 2003

Don't know about RFM's (just thing about that tip velocity), but a square bailer without a kicker can very nearly turn into a kicker bailer if run on 1,000 rpm. My dad's David Brown has a 2 speed PTO, only one shaft, pull up the lever for 1,000, down for 540. Mom pulled up once. That bailer was plunging like a mad plumber. Dad looked at me, I looked at dad, and the light bulb came on for both of us. We got it slowed down before self destruction, but it was imminent. Most larger tractors have 2 shafts with different spline configurations such that you can't screw up and make the wrong connection.

Our sheller wants about 800 rpm to work right, works well on the 2 speed, just idle down a bit and there you go. At 540 it seemed to turn the corn to meal, not enough air velocity to blow the shelled corn out of the mill.

Nick

AMP762 · Mar 21, 2003

in soft dirt at 1000rpm my JD tiller will flat make a nice seed bed /forums/images/graemlins/cool.gif

frank_f15 · Mar 21, 2003

nope : rfm run at 540 rpm and all new er tractors will have rear pto @540 rpm, your engine rpm will differ with different tractors to attain the 540 pto speed.

HayDR · Mar 21, 2003

It is very dangerous to use any 540 RPM implement at a 1000 PTO speed. It will void the warranty! If you need a bigger tractor buy one. A finish mower used in this manner could cause serious injury or death. Please guys do not encourage anyone to play with the thought of trying this.

pennwalk · Mar 21, 2003

I think pto pumps and generators are designed to run at 1000 rpm. I have read about running an implement on the 1000 rpm setting and ideling back the engine till the pto is spinning at 540, The theory is that it increases fuel econemy and cuts down on engine wear and tear. The problem I see with that is that most of these engines were designed to run best at pto speed which is often marked on the meter. Big farm tractors sometimes have two pto stubs which are different so you can't hook up the wrong kind of implement to the wrong stub. I have seen Woods rear finish mowers that were designed to run off the Kubotas 750 rpm setting.

Chris

herbenus · Mar 21, 2003

Since we're on the subject. I seldom even run my brush hog to 540 rpm. I'm usually just cutting grass which may get to 1 foot, but normally less. It seems to cut okay, faster is definitely a little better. But with the manual transmission I have, I'm comfortable with a particular gear setting and rpm and feel there's probably a benefit to the engine. I'm at work, but I think engine rpm is 2000 and something and I really like to keep it around 1500-1700 - just sounds better.