Driving Hard

Muncie Power Products (distributed in Canada by Toronto-based Drive Products) produces several six-bolt PTOs for Allison Series 1000-2000 transmissions, including the CS model in torque capacities to 300 pounds-feet. Muncie’s drive gears for these PTOs are driven by a torque converter rather than an input shaft. That way, PTO speeds are dependent on the speed of the vehicle when in drive or reverse and operating at low speeds, but on engine speed when the truck is in park or neutral.

Muncie also developed variations of its TG, CS, and SH PTOs for Eaton Corp.’s Lightning Series transmissions. For very heavy-duty applications, SH PTOs provide maximum power output with torque capacities up to 400 pounds-feet.

The Chelsea Auxiliary Power Group of Dana’s drivetrain division offers PTOs for Allison Series 1000, 2000, and 2400 automatics. The 250-Series model is available as a 12- or 24-volt electric-over-hydraulic shift unit. It’s also compact, fitting easily into small spaces.

Caterpillar now offers a flywheel-driven rear PTO option for its 3126 engine, which saves adding front frame extensions. That allows for a 24-inch longer chassis and wheelbase to maximize payloads, adding up to 1500 pounds of capacity to a Cat-powered truck, the company says. Another advantage: shorter hydraulic lines, reducing pumping loss and eliminating the need to modify the radiator. The output shaft ratio is 1.31:1, and it has a 200-horsepower continuous rating.

Cat’s PTO option adds just 83 pounds to the truck weight.