M8540/M9540 540/1000 rpm PTO Conversion install

[bjmsam]

I'm curious if a noticeable savings in fuel consumption can be noticed.

My understanding is that for a given load, a diesel engine uses about the same amount of fuel regardless of RPM. I was hoping to reduce noise when operating the PTO generator at loads that my L3710 can handle at a lower, quieter engine speed since the tractor is running adjacent to the house it's powering.

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 Hub City Model 390 PTO Speed Changer is in the $2k range. Ouch!

Thanks to you both for such informative threads!

 

[ovrszd]

Yep, I understand the noise thing for stationary operation for sure!!!

I am just assuming theirs an economical reason that manufacturers are selling tractors with reduced engine speed PTO operation. I think JD even calls theirs ePTO (economical) and talk about cheaper operation??

 

[rbargeron]

An advantage with my L5450 conversions was the pto gearbox was already designed to have the extra gears - earlier serial numbers had included it but I'm guessing the accountants or product liability lawyers had weighed in. With the back end lifted the oil ponded forward - no need to drain any. You can try that on your next one:thumbsup:
Take care - good job, good posts Dick B

 

[ovrszd]

Yeah I parked on some blocks but still had to catch some fluid. To swap cases you are about 1.5" from the bottom of the housing.

I think the omissions we see in later models is always dollar driven. Most operators wouldn't even notice that the tractor wasn't equipped with it anyway.

 

[rbargeron]

......manufacturers are selling tractors with reduced engine speed PTO operation. I think JD even calls theirs ePTO (economical) and talk about cheaper operation??

I think the "economies" of lower-rpm operation are from lower friction losses, less waste heat, less mechanical wear of everything. But the actual job being done by the pto shaft uses the same amount of power - so fuel savings are small. Reduced noise may reduce operator fatigue - so you won't take up hang gliding, short out the grid, raise the crime rate, get your dad punched over a can of soup, etc.

 

[ovrszd]

I think the "economies" of lower-rpm operation are from lower friction losses, less waste heat, less mechanical wear of everything. But the actual job being done by the pto shaft uses the same amount of power - so fuel savings are small. Reduced noise may reduce operator fatigue - so you won't take up hang gliding, short out the grid, get your dad punched over a can of soup etc.

Heheheheheh. Good one!!!

 

[sixdogs]

Great write up and especially great photos. They really tell the story.

 

[ovrszd]

Great write up and especially great photos. They really tell the story.

Thank you. I swap speeds 4-5 times a year.

 

[Rustyiron]

I lately learned that more hp can be delivered through an equal shaft at a higher rpm. That was probably not worded the right way but I wonder if that was the original reason for 1000 rpm pto's, as I remember it seemed that they first appeared on the higher HP tractors.
:confused3: I'm not clear if this apply's to gear box's and other components as well.

 

[rbargeron]

...... I wonder if that was the original reason for 1000 rpm pto's, as I remember it seemed that they first appeared on the higher HP tractors.......

PTO speeds are chosen to serve the implements in each market. Some quite small tractors made in Japan and other parts of the world have had multiple pto speeds for years, mostly to power various harvesting machines.

Safety and failure are issues if an implement is driven beyond its design speed, so higher-speed ptos are no longer common on homeowner machines. Attachments of different speeds now typically are segregated by front/rear mounting, different shaft coupling style and rotation.

Multi-speed rear ptos have re-emerged on larger tractors - perhaps because their operators tend to have more machine training and experience ?