DF 254 PTO Speed

[Rich Waugh]

Hypothetically at least, six-spline PTO's are for 540 rpm implements and 1000 rpm implements use a higher spline count so they don't inadvertently interchange. That's theory, anyway. In theory, there's no difference between theory and practice - in practice there is. :laughing:

 

[coondle]

Manufacturers developed 1000rpm pto to lower torque requirements for the engine to implement drive shafts because the standard pto shaft size was long established at 1and3/8 six spline
That became necessary with higher horsepower tractors appearing on the market from the late 1960's on these high horsepower tractors just twisted up and screwed off the drive shafts either in the tractor transmission or leading to the implement gearbox
Every manufacturer as has been said designs their machines to run optimally at a given rpm 540 etc however many implements are past the first flush of youth and those only needing light torque demands if they have some wear may sound happier at a slightly lower rpm BUT DO NOT load the implement up to its capacity as the torque load on the implements gearbox/drivetrain will become exessive
This speed/torque balance for rotating shafts can be often seen with big4WD tractor manufacturers that use truck style differentials then put reduction hubs at the wheels

 

[Bob Rooks]

Hypothetically at least, six-spline PTO's are for 540 rpm implements and 1000 rpm implements use a higher spline count so they don't inadvertently interchange. That's theory, anyway. In theory, there's no difference between theory and practice - in practice there is. :laughing:

Rich is correct. The 1-3/8" six spline PTO is intended for 540 and 720 r/m implements. The 1,000 r/m PTO is 1-1/2" diameter and 21 spline. These are ASAE standards. However, you can purchase a myriad of adapters to connect just about anything to anything. Another caveat is that Chinese tractors don't always follow the rules, so you may get a 1,000 r/m PTO with a 1-3/8" six spline shaft.

 

[reelnative]

my df tractor has 540 and 1000 and a 6 spline shaft, i allways thought the 1000 was for when you wanted to run somthing like a log splitter or somthing like that at a lower rpm and still get the 540 range, and my rpm for the 540 is 2000 to 2200rpm

 

[Rich Waugh]

I think the real reason for the two PTO speeds is simply sales appeal. Very few major name tractors that I've seen had anything but a single speed PTO, and I think the Chinese, in their customary fashion of looking for a little "bling" to add, decided to offer a two-speed PTO. It only takes one or two extra gears and a selector, so manufacturing cost is small and then they can say they have the higher speed for running a PTO hydraulic pump or some such. Just look at how Harbor Freight's Chinese-made tools are generally knock-offs of a familiar US brand but with an added extra. Like my Taiwanese-made band saw, a knock-off of the venerable Rockwell Model 14, but the Chinese added a jackshaft and stepped sheaves so it will also cut metal, something the Rockwell can't do. Sales appeal. Good grief, look how they add a "laser sight" to everything, even a jig saw, of all things! That one still cracks me up. It's all about the bling!

It's also remotely possible (another thing the Chinese add to everything possible - remote control) that there is a body of legacy implements in Asia that are intended to run at higher PTO speeds - I don't know.

 

[SPYDERLK]

I read this, and thought, "actually I can't remember why I put the lever forward"

The knob on the top is marked for 540 and 1000, but turns freely. Anyhow, I went and checked. I have been using the correct setting -thank the lord, I think I'd die of shame if I'd been getting it wrong all this time.

I've been running a flail topper this morning. 2200 on the tacho and the topper seems fine, so I guess that 2200 is correct, as everyone says.

So am I wrong running rakes and tedders at lower rpm. They don't seem too happy running fast, or is it my lack of nerve?

Many implements are not full rpm critical. I rarely run my tedder at anywhere near 540. It tears the hay up.
larry

 

[Agvg]

my df tractor has 540 and 1000 and a 6 spline shaft, i allways thought the 1000 was for when you wanted to run somthing like a log splitter or somthing like that at a lower rpm and still get the 540 range, and my rpm for the 540 is 2000 to 2200rpm

Thats the common use for 1000 rpm PTO, and 1000 rpm has been quite normal on tracktors for 30 years.

There is not much rear mounted 1000 rpm equipment here i live but I think on front mounted 3pt the std PTO is 1000 rpm.

 

[coondle]

Japanese certainly took up multi speedTO on small tractors 25 or 30 years ago. I had a shiaura with 4 speeds for the pto, never worked out what they all were as I only had 540 gear and once I worked out the 540 selector position did not look further. Only had a 6 a spline shaft. The korean Daedong 90 hp had 2 speeds, 540 and 750, with a 6 spline shaft. My massey ferguson 254 (47 engine) really a landini in red paint had 540 and 1000 selectable on a lever on lhs of rear transmission housing and again only a 6 spline shaft. My case 1070 and my case 2290 both had 540 and 1000 selectable by reversing the pto shaft. Each end has a different reach so engages a different gear and the end showing for 540 is 6 spline and for 1000 is multi-spline, very clever.

 

[Agvg]

Think the 6 splines is almost the only type used on normal tracktors, on many you can switch the shaft but its vert rare to see the 21 splines.

But the user must be very carefull when using 540rpm attachments on 1000rpm speed, bad things can happen if you forget and gives full engine speed.