Heavy Duty PTO Applications
|
Often times I am led to believe that modern driveline applications have reached their mechanical limitations. Horsepower output is at an unbelievable level, and what were once simple implements used to till and sow are now complex engineering marvels in their own right. Remember, the driveline (or PTO shaft) transmits torque across three dimensions. What other componant part does that ? Therefore, its function is a product of trigonometry, not merely two-dimensional mechanical physics. Just because a universal joint is rated to carry the predicted torque load does not mean it is sufficient to handle the additional thrust loads of a particular application. |
 |
Considerations:
Non-parallel installations produce thrust.
Steep angles produce heat.
The shorter the driveline, the more severe the angles.
Plastic shields protect PTO shafts from dirt and other contaminants. |
 |
Maintenance:
Different applications require different maintenance schedules. The more abusive the environment, the more critical a new shot of grease can be. Steep drivelines will produce heat, thus degrading the lubricant more rapidly than a "flat" shaft will. Thrust also produces heat as well as forces that are contrary to torque. Inconsistent torque loads are harder on component parts than consistent ones.
By observing and inspecting your PTO on a regular basis, not only will you develop a "feel" for your maintenance needs, but you will most likely have a safer application too. |
| |
The Industry:
Because of the increases in tractor PTO horsepower and sophistication in implement design, the leaders of the PTO industry have responded with new universal joint sizes and new engineering designs. In short, they are making bigger, more expensive PTO shafts.
We have always represented our PTO shafts in the same way the OEM has represented them to us. All of our catalog pages contain torque information that comes directly from the given manufacturer. In comparing the maufacturers' listed torque ratings, a person could become extremely confused. Therefore, we recommend comparing universal joints by their outer dimensions, with the understanding that internal design also influences torque potential and each manufacturer has his own specific engineering data. (See OEM's web site for details) |
Heavy Duty PTO Sizes (old and new) 
| Manufacturer |
Series |
UJ Specs * by mm
(cup x length) |
Shaft Profile |
Constant Velocity |
notes |
| Bondioli & Pavesi |
Size 10 |
41 x 118 |
Tri-tube *outer=66mm |
no |
|
| Bondioli & Pavesi |
SH |
42 x 107.5 |
4 lobe * outer=70.2mm |
yes |
|
| Bondioli & Pavesi |
SO |
42 x 130 |
4 lobe or 45mm splined |
no |
|
| |
|
|
|
|
|
| Walterscheid |
2500 |
36 x 89 |
star or 40mm splined |
yes |
|
| Walterscheid |
2600 |
42 x 104 |
star or 52mm splined |
no |
|
| Walterscheid |
2700 |
50 x 118 |
52mm splined |
no |
|
| |
|
|
|
|
|
| Weasler |
55N |
38 x 109.5 |
42.8mm splined |
yes |
|
| Weasler |
77 |
product is not available |
|
|
|
Catalogs by Drive Line Service of Fresno, CA Inc @ 800-824-0706 - Parts Dept.
Size 10 has been available for many years and has proved to be a tremendous workhorse. We are told that this assembly is in the process of becoming obsolete. Currently, we have stock on assemblies as well as parts. Component parts will be available for many years whether they obsolete the series or not. 
back
The SH series is one of the new SFT series shafts. Its new 4 lobe tube profile appears to be the closest fitting tube style ever designed and the SFT shielding design surpasses all present requirements. Best of all, the SH series can be purchased as a constant velocity shaft, making it the highest rated CV PTO we know of. Bondioli and Pavesi has re-engineered all of their CV joints for longer life and less required maintenance.
* To date we have sold nearly 100 of the new CV units in smaller UJ sizes. The new technology works! * back
The SO series is one of the new SFT series shafts. Its new 4 lobe tube profile appears to be the closest fitting tube style ever and the SFT shielding design surpasses all present requirements.
The SO also comes in a splined assembly that we will be keeping in stock @ 24" cuj-cuj closed. 
back
The 2500 series is a long time favorite. At one time it was the largest of universal joints, but today it is the smallest Walterscheid catagory 6 joint. We consider this series to be one of the most versatile on the market. It is relatively inexpensive by comparison. It is widely available. There are a host of clutches made for the 2500 as well as a wide variety of implement end sizes. It comes in two CV sizes, the 2580 and the PW580.
back
The 2600 has been converted to Walterscheid's new "PRO" series. The new shielding design promises to last longer and protect better. Our inventory includes splined components and star profile.
back
This behemoth universal joint is the largest and most expensive agricultural PTO joint available. We carry a full line of 2700 series parts.
back
The 55N is the oldest of the heavy duty UJs in our inventory. It is a USA product and by far the most popular of the group. Although it can be purchased in a square shaft profile, we prefer using Weasler's durable 1.687"-20 spline stock. Our inventory includes nearly every 55N yoke available today and constant velocity assemblies ready to go.
back
