DF 254 PTO Speed

[Ross71]

The DF254 has two PTO speeds, 540 and 1000. Great, but at what engine rpm? I've looked in the operator manual, I e mailed Dong Feng but can't find the info. I think it is 540 pto rpm at 1500 rpm engine speed(or 1000pto rpm) but does anyone actually know what is the magic number?

Cheers, Ross

 

[RonMar]

The PTO speed is what the output shaft turns with the engine at FULL rated RPM. There should be a mark on your tachometer around 2200-2300 RPM(mine has a green arc in this range. It is also the peak RPM your governor should be set to maintain at the full throttle position. Basically the maximum sustainable HP output RPM... So, need 540 RPM to run the brushhog and mow, or run the chipper? Set the selector lever to the 540 position, push in the clutch and engage the PTO lever. At idle RPM, Slowly let out the clutch to spin up the mower chipper ect. Once the clutch is out/PTO fully engaged, slowly push the throttle lever to full to accelerate the blades to full RPM, and leave the throttle in the full position. If mowing, select the appropriate gear to deliver the desired groundspeed.

Don't think I have ever seen a 1000 RPM PTO impliment. It would probably be best used if driving a PTO water pump(transfer or fire) IF you are just mowing the lawn, you probably do not need full engine HP. but still need 540 RPM for mower blade tip speed. To make things a little less noisy, you can select 1000 PTO RPM on the lever, but only run around 1150 engine RPM which will get you 540 RPM on the PTO shaft at reduced available HP. I do this occasionally when mowing grass on level ground... You MUST use caution when doing this though as overspeeding a 540 RPM impliment such a s a brushhog/shredder, mower or chipper can lead to rapid violent death when it throws a heavy steel blade or the gearbox explodes...

 

[Diamondpilot]

What Ron said is all true but for the health of you engine and gear box It's much wiser to just run it at 540 and the green arch on the tach. If not you are lugging the engine and causing premature wear through stress.

Diesel engines are happy running at max power for long periods of time. Its still a relatively low rpm and does no harm.

Chris

 

[Bob Rooks]

FYI. 1,000 r/m implements will have a 21 spline shaft. This is to keep them separate. The only two speeds that work with a 1-3/8" six-spline shaft are 540 and 720 r/m. However, I'm told that some, but not all, Chinese tractors will have 1,000 r/m PTO output speed in the high range.
On my Yuchai dozer I get 540 r/m PTO speed with the throttle set at 1,850 r/m. Personally, I don't advise running against the governor stop because that's all you will get and no more. No reserve. Best to check it with a photo tach, that's what I did.

 

[cleat]

My DF254 needs the engine to be at 2200 RPM to get 540 PTO. I checked this using a hand held tach.

However, I usually mow at 2000 RPM because I get a good cut with a little less noise at this RPM.

I blow snow at around 1600 - 1800 RPM unless I am into really heavy drifts.

Cleat

 

[Ross71]

Thanks for the replies. My tractor has a green arc on the tacho from 700rpm around to 2500. More than that is red, below 700 is yellow. Apart from the numbers, and those coloured zones there's no other marks(not even the maker's name).

The twin rotor rake I've been using is meant to be run at 540. It seems to be right at about 1650 engine rpm. At 2000 engine rpm the rake was going way too fast.
I think I need to get a hold of a hand tachograph....

Ross

 

[greg_g]

Interesting that there's no mark on the tach to indicate PTO revs. If the tines are spinning too fast at 2000 rpm, you may inadvertently have the PTO speed select lever in the wrong position. Rather than the desired 540, you could be in the 1000 (possibly 720) position.

//greg//

 

[jimogeek]

Mine is the same way, have a 2006 foton 250. No green band and the sticker was missing from the 540/1000 selector lever. Figured it out pretty quick though, no way I could cut grass at 1000 rpm but I may have gotten a finish mower just a bit larger than I should have anyway (72" king cutter finish mower).

 

[Ross71]

Interesting that there's no mark on the tach to indicate PTO revs. If the tines are spinning too fast at 2000 rpm, you may inadvertently have the PTO speed select lever in the wrong position. Rather than the desired 540, you could be in the 1000 (possibly 720) position.

//greg//

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?

 

[greg_g]

Implement manufacturers optimize design efficiency relative to a specific number of PTO revs: 540/720/1000. The vast majority of PTO implements sold for this class tractor in America seem to be 540. Not that you cant find the occasional 720 or 1000 implement. Its a simple matter of trusting the manufacturer to specify the correct speed

//greg//

 

[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.