Understanding power take-off systems S i x t h e d i t i o n

1 Understanding power take -off systems Sixth edition Muncie power Products Welcome to the sixth edition of Muncie power Products' Understanding . power take -OFF systems , the companion piece to our Understanding . TRUCK MOUNTED HYDRAULIC systems booklet. Together these contain a body of valuable information on providing dependable auxiliary power on today's work trucks. Many sources are called upon to produce an accurate and useful technical/training publication. We thank the officers, employees, and customers of Muncie power Products for their many contributions.

2 Special appreciation goes to Rick Wallace, power take -Off Product Manager, and Muncie's engineering team in Tulsa, OK. for developing the quality PTO products that make Muncie power Products, Inc. the leader in the industry. The illustrations, design, and graphics for this booklet, as well as all of Muncie's sales and support literature, were contributed by Tony Jeroski and Mark Sherfick. We encourage anyone wishing to become more familiar with Muncie power Products, Inc. to visit our web site, , to learn more about our company and products.

3 While there be sure to click on the link to our M- power Customer Assistance Software for assistance in selecting the right Muncie PTO or hydraulic product for your application. David L. Douglass Director of Training muncie power products quality policy Muncie power Products is dedicated to providing quality products and services that will satisfy the needs and expectations of our customers. We are committed to the continual improvement of our products and processes to achieve our quality objectives, minimize costs to our customers and realize a reasonable profit that will provide a stable future for our employees.

4 Table of Contents power take -Off Defined 3. power take -Offs A Brief History 4. The Transmission Aperture 6. The power take -Off Input Gear 7. PTO Speed and Rotation 8. PTO Selection 9. The Muncie PTO Model Number 11. PTO Torque and Horsepower Requirements 13. Adapter Gear Assemblies 14. Intermittent and Continuous Duty Cycles 15. Types of power take -Offs 17. PTO Installation Backlash 18.. power take -Off Defined power take -Offs (PTOs) are mechanical gearboxes that Truck Classification By GVWR. attach to apertures provided on truck transmissions and (Gross Vehicle Weight Rating).

5 Are used to transfer the power of the vehicle engine to Class 1 Less than 6,000 lb. auxiliary components, most commonly a hydraulic pump. The hydraulic flow generated by the pump is then directed Class 2 6,001-10,000 lb. to cylinders and/or hydraulic motors to perform work. In Class 3 10,001-14,000 lb. some PTO applications such as generators, air compres- Class 4 14,001-16,000 lb. sors, pneumatic blowers, vacuum pumps and liquid trans- Class 5 16,001-19,500 lb. fer pumps, the PTO provides power , in the form of a rotat- Class 6 19,501-26,000 lb.

6 Ing shaft, directly to the driven component. Class 7 26,001-33,000 lb. The power take -off we are most familiar with is the side- Class 8 33,000 lb. and up mounted PTO, although there are also models that attach to the rear of certain transmissions and split shaft PTOs that are mounted by removing a section of the vehicle's main driveline. Rear-mounted PTOs are frequently referred to as countershaft PTOs although, in truth, many side- mounted PTOs are also driven by gears on the transmis- sion's countershaft and so are also countershaft PTOs.

7 You may hear people refer to side countershaft and rear countershaft power take -offs to make a distinction. Transmission with PTO and The transmissions commonly found in class 4 and larger hydraulic pump installed. vehicles will have provisions for the mounting of a PTO. Generally there are two apertures, one on each side of the transmission, although some smaller transmissions may have only one. When discussing aperture location one re- fers to the passenger side of the truck as the right and the driver's side as the left.

8 Many popular Eaton Fuller transmissions have a PTO aperture on the bottom (offset to the left), and some Allison automatic transmissions have Air Shift Cover a top aperture. The power take -off may be engaged by means of a cable, lever, air pressure, or hydraulic pressure. The latest PTO. shifting design incorporates a small electric motor and hy- draulic pump within the shift cover assembly to provide hydraulic force to engage the PTO. Cable Shift Cover Various output shaft configurations are available to allow for a driveshaft connection or the attachment of hydraulic pumps directly to the PTO without an intermediate shaft.

9 The Society of Automotive Engineers ( ) has estab- lished standard mounting face dimensions for hydraulic pumps and PTOs are made to accept these. These are referred to, from smallest to largest, as the A, B, D, Lectra Shift Cover E and F.. power take -Offs A Brief History The earliest documented use we have of a power take -off is 1919 when a PTO was utilized to power an air compres- sor to inflate tires on a Cadillac automobile. By the 1930s PTO apertures were standard on truck transmissions and 828 power take -offs were being used to power winches, dump bodies, and garbage trucks.

10 Early PTO manufacturers in- cluded Gar Wood, Central Fiber Products, Spicer, Tulsa Winch, Arrow, and Braden. These early manufacturers no longer exist as PTO manufacturers. Braden and Tulsa Winch still exist as successful manufacturers of mechani- 838 cal and hydraulic winches. Eventually, Central Fiber and Spicer were acquired by Dana Corporation and their PTO. products were combined into the Chelsea PTO line. Park- er Hannifin Corporation now owns Chelsea. Muncie power Products began in Muncie, Indiana in 1935. as Muncie Parts Manufacturing Company, a distributor of CD10 auto parts.