M8540/M9540 540/1000 rpm PTO Conversion install

[ovrszd]

The integral model weighs 2006lbs, and that is with only two tail wheels. I have a manual right here if you need any other specs or info.

Thanks for the info. I'm probably around 2200lbs with four wheels. If you don't have your 1008 anymore would you consider selling the manual??

 

[ovrszd]

We run a Bush Hog 3008, 2 pt hitch with our M8540 and the best thing about the mower is the tires! The dealer ordered it with (used) airplane tires and those stay on top and roll easily over everything. In 5 years of hard use the tires have not been punctured.
Those tires I would suggest to anyone with a big, heavy mower behind.
Looks like the 1000rpm conversion kit is a winner, too!

Yep, as heavy as these cutters are it would be an issue in soft ground. I think the guy that owned my cutter previously did fiinish mowing and didn't want tire ruts or scalps so he added two more wheels.

 

[Verticaltrx]

Thanks for the info. I'm probably around 2200lbs with four wheels. If you don't have your 1008 anymore would you consider selling the manual??

Still have it and going strong :thumbsup:

 

[ovrszd]

Still have it and going strong :thumbsup:

View attachment 299757

Cool, that's reassuring!!!

 

[bjmsam]

the gearbox is thicker due to having two sets of gears

How is the new gearbox switched between 540 RPM and 1000 RPM? I don't see a lever.

 

[xring100]

You have to swap output shafts one is 6 splines I believe the 1000 rpm is 21 splines

 

[ovrszd]

How is the new gearbox switched between 540 RPM and 1000 RPM? I don't see a lever.

If you go back to my first post and look at the third picture, it's of the housing extension with the PTO shaft removed. It also shows the two shafts and a snap ring laying in the foreground.

To change speeds you remove the snap ring and pull out the existing shaft and replace it with the other shaft. If you look closely at the two shafts you will see that they are each driven by a different gear. You can tell by the location of the teeth on the two shafts. So 540 engages one gear in the housing assembly. 1000 engages a different gear.

Warning. When you swap shafts park the tractor nose downhill so fluid doesn't run out. If parked flat the oil level is slightly above the opening and will pee out fluid. You know exactly how I figured that out don't ya....... :ashamed:

 

[bjmsam]

If you go back to my first post and look at the third picture, it's of the housing extension with the PTO shaft removed. It also shows the two shafts and a snap ring laying in the foreground.

To change speeds you remove the snap ring and pull out the existing shaft and replace it with the other shaft. If you look closely at the two shafts you will see that they are each driven by a different gear. You can tell by the location of the teeth on the two shafts. So 540 engages one gear in the housing assembly. 1000 engages a different gear.

Warning. When you swap shafts park the tractor nose downhill so fluid doesn't run out. If parked flat the oil level is slightly above the opening and will pee out fluid. You know exactly how I figured that out don't ya....... :ashamed:

Ah, that makes sense, and helps explain these posts from an earlier thread:

Here's a pic showing the new gears, thrust washer and inner race. The upper pinion is 2-pieces.

This went really well - here is the finished 2-speed box ready to go back on. The leftover parts to the right are the old single pinion, its gear, and the dummy spacer that's been replaced by the new gear and race.

Toughest part of the job was getting the old gasket cleaned off - they use some serious adhesive at the factory.

I'd love to find such a kit for my L3710 to spin a 540 PTO generator at a slower engine speed.

 

[wmonroe]

I don't think Kubota makes a kit for the L's do they? I would buy one if they did.

 

[bjmsam]

Yes, for some L models, anyway - here is a quote from the thread I referenced in my previous post:

My L4150 had a 2-speed pto, 540 and 750, which was very handy - often I could save fuel, noise and engine wear by running the higher pto speed but with the engine at around 1800. Also, I could run my snowblower up a little to get better throw distance.

My L5450 only has single-speed 540 pto. So I run the engine at 2300 rpm or even higher, but would like a faster pto gear like I had before.

In going over the 5450 parts list, it shows that the tractors in this series made for Australia and New Zealand have 2-speed pto. I've compared the lists and by replacing 2 parts and adding three new ones, my rig will have both 540 and 900 (approx) pto speeds.

 

[ovrszd]

Some manufacturers make PTO systems now that run at a reduced engine speed. The method used varies, but the end result is the same. Wish I had something like that on my tractor.

Most of my PTO use is running a 10' 1000rpm brush cutter. I wish I could do that at a reduced engine speed. I have plenty of HP for the job and could benefit from less engine speed

The conversion kit I installed was to specifically change the tractor's PTO speed from 540 to 1000. I guess I could convert the PTO shaft on a 540 attachment to the 21 spline of my 1000 rpm shaft and then run the engine at a reduced speed to attain 540rpms to the attachment.... Wonder if anyone has ever tried that???

 

[xring100]

I believe I have seen adapters at tsc
Yep here it is
21-Spline To 6-Spline Adapter - Tractor Supply Co.
https://www.google.com/url?sa=t&sou...rE0jWfKpd1CDHJEDg&sig2=4eJWt_EjW4h30VNxzhZYYA

 

[bjmsam]

The conversion kit I installed was to specifically change the tractor's PTO speed from 540 to 1000. I guess I could convert the PTO shaft on a 540 attachment to the 21 spline of my 1000 rpm shaft and then run the engine at a reduced speed to attain 540rpms to the attachment.... Wonder if anyone has ever tried that???

That's exactly what I wanted to do, but further research revealed that it may not be such a good idea for my application anyway; a factsheet published by the Ontario Ministry of Agriculture and Food titled Tractor-Driven Generators: Producing Quality Power states, "Operating a tractor with a 1000 rpm PTO at approximately one-half its rated engine rpm to deliver 540 rpm to the generator is not a recommended practice - do not operate your tractor with 1000 rpm PTO and half engine speed." Oh, well.

 

[ovrszd]

Dave,,, forgot about those, that would be easier than converting the spline end of the PTO shaft and is easily reverseable. I guess the only issue would be PTO shaft length, with the adapter the shaft might be too long?? Thanks for posting this!!!

 

[ovrszd]

That's exactly what I wanted to do, but further research revealed that it may not be such a good idea for my application anyway; a factsheet published by the Ontario Ministry of Agriculture and Food titled Tractor-Driven Generators: Producing Quality Power states, "Operating a tractor with a 1000 rpm PTO at approximately one-half its rated engine rpm to deliver 540 rpm to the generator is not a recommended practice - do not operate your tractor with 1000 rpm PTO and half engine speed." Oh, well.

Hmmmm,,, wish they had elaborated on the problem with doing that. I can't think of any mechanical reason that it wouldn't work??? My tractor's electronic dash gives me PTO shaft speed. It can be switched back and forth between 540 and 1000 depending on which you are using at the time. By leaving my dash setting on 1000 and setting the tractor's engine speed to attain 540 I'd be accurately controlling the attachment speed so I can't see how I could damage it. By running the 1000rpm PTO setup at a reduced speed I can't see that any damage to the tractor would occur. Curious why they say that???

 

[bjmsam]

Perhaps it would not be a problem for your application.

Operating at Half Engine Speed

Farm tractor diesel engines are designed to develop optimum horsepower and torque at a specific rated engine speed.

Operating a tractor with a 1000 rpm PTO at approximately one-half its rated engine rpm to deliver 540 rpm to the generator is not a recommended practice.

Chart 8 shows the results of one test where this mode of operation was attempted. The frequency decreased by 10% when 30 % of rated load was applied and by 16% at 60 % of rated load. Clearly unacceptable, for producing quality power.

Chart 8. Significant change in frequency takes place when operating at half of rated engine rpm.

While the engine horsepower would be significantly reduced at half the rated engine rpm, the bigger problem is that at this speed the engine is operating on the unstable side of the torque curve. An increase in load will cause a reduction in engine speed, which causes a reduction in torque, which causes a reduction in speed, resulting in tractor stalling or speed cycling erratically up and down.

Some tractors are now equipped with an "economy" 540 rpm PTO as well as the "standard" setting. One tractor with this feature was tested. Operating with the "standard" setting produced a 2% drop in frequency from no-load to full-load operation. The frequency drop while operating in the "economy" setting was in excess of 6% for the same loads.

When selecting the engine operating speed to deliver 540 rpm at the PTO:

• set the engine close to manufactures recommended engine speed for 540 rpm
• adjust frequency to 60-62 Hz
• use a factory "economy" setting for light consistent loads
• do not operate your tractor with 1000 rpm PTO and half engine speed.

 

[xring100]

Dave,,, forgot about those, that would be easier than converting the spline end of the PTO shaft and is easily reverseable. I guess the only issue would be PTO shaft length, with the adapter the shaft might be too long?? Thanks for posting this!!!

No problem

 

[ovrszd]

I agree that if I'm operating an attachment that requires maybe 80% or higher of my tractor's HP/Torque that reducing engine rpms would not be effective and would make it difficult to maintain constant attachment speed.

I didn't see anything in the data that indicated damage to the tractor or attachment. It just warned of the inability to maintain speed. I agree with that.

I think for light duty attachments it would not create a problem. I've got a 6' 540rpm brush cutter. I'll hook it up next Summer and try running my tractor at reduced engine speed using the 1000rpm shaft converted. Not really a great test because the cutter is way below the tractor's ability to operate, but I'll give it a try. Wish I had a 540 attachment that would load the tractor to test with. I'm curious if a noticeable savings in fuel consumption can be noticed.

 

[rbargeron]

Back in 2002, I posted the prior thread about converting to 2-speed pto . Later in 2008 I converted another L5450 the same way. Except for the L4350, L4850 and L5450, I've not seen any other models where the conversion is this direct and low-cost (about $300 in parts). For my uses, 150% is a more versatile second speed.

For the big engines in the M8540 and M9540 the replacement gearbox from Kubota fills a need - its good that they offer it.

Regarding other tractor brands and models, the design requirements for a pto speed increaser drive the cost high. It should be (1) shaft mounted and supported (2) rotate the same way (3) provide step-up of about 50% (4) input and output on the same centerline (5) include a bi-directional torque resistance (6) sealed oil-bath housing (7) compact and light-weight. For a time there was one like this (Comer A-20A from Italy) but it was priced around $1k when I inquired.

The big factor in all this is that the engine has to be big enough to have plenty of power and good governor response when running at lower rpm with smaller loads. My L5450 makes around 50 pto hp so the higher pto ratio (780 rpm) works fine for things like snowblower, rotary and finish cutters, and a pto generator. I run the engine at 1700, where it makes maybe 25% less hp, but still responds well to varying load.

 

[ovrszd]

I probably wouldn't have bought my conversion just as an add-on. I was shopping for a brush cutter and found a JD M1008 1000rpm for $1800. All others I had found were in the $3K range. I decided I could add the PTO conversion and buy the cutter for what I'd pay for any other cutter I'd found. Looked like a win/win to me.

I looked at a parts breakdown of my tractor to figure out what I was getting for the money. I really thought I'd get a box of parts and have to put it all together, similar to the conversions you are talking about. I was pleasantly surprised when it came assembled. I took my time installing because I just didn't see how it could be that easy. Now that I've done one I could do another in 30 minutes. Takes longer to deal with the fluid than anything else. Also came with a longer drawbar because it moves the shaft rearward a few inches.

Thanks for your posts.