Which PTO Best Fits Your Allison 3000/4000 Series Transmission?

The Allison 3000 and 4000 Series are automatic transmissions built for demanding vocational work. Reliability and durability are critical in the industries where Allison 3000 and 4000 Series can be found. And having the right power take-off (PTO) is important to keep each application running the way it should.

Four PTO series mount directly to these transmissions with the 10-bolt opening: the A20 Series, the A30 Series, the A40 Series, and the A50 Series.

Three questions help you decide which one you need:

• What application will your PTO operate?
  • Applications such as fire trucks are considered continuous duty and require derating the PTO by 20%. Depending on your torque and horsepower requirements will determine whether an A20 Series or a heavier-duty PTO like the A40 Series is your best fit.
  • Other applications like blowers and vacuum pumps, where clutch shift PTOs are often not recommended for high inertia applications, PTOs like the A30 Series and A50 Series are better suited to these applications. This is especially important when the PTO is constantly engaged when the engine is running.
• How much torque does your driven equipment require? 
  • The A20 Series and A30 Series are rated up to 415 lbs. ft. The A40 Series and A50 Series are rated up to 646 lbs. ft.
• Does the PTO need to disengage while the truck is running? 
  • Clutch shift PTOs engage and disengage from the cab with the engine running. Constant drive PTOs turn whenever the engine turns: no shift hardware, no cab switch to install, and no way to stop the PTO without stopping the engine.

A20 SERIES: CLUTCH SHIFT

The A20 Series is a medium-duty, 10-bolt clutch shift PTO. It has a shift cover allowing 360-degree rotation, a proven clutch pack design, tapered roller bearings, three housing arrangements, and a rotatable pump flange. Having a rotatable pump flange allows flexibility while mounting a pump, making it easier for installers to quickly install a hydraulic pump. 

The A20 works best when working with applications such as dump trucks, fire and rescue, refuse, utility, tow and recovery, bulk hauling, and snowplows.

Part number example: A20-A10**-HX3X4PX

A30 SERIES: CONSTANT DRIVE

The A30 Series is the constant drive version of the A20 Series. Same ratings, same ratio set, same rotatable pump flange, without the shift hardware.

You should select the A30 Series when the equipment driven is meant to run while the truck runs and you do not need to disengage the PTO. Common applications include refuse trucks, cranes, snowplows, and cement mixers.

For applications that require a larger pump, consider adding an EX Drive shaft extension for additional mounting clearance. 

Part number example: A30-A10**-MX3X4PX

A40 SERIES: CLUTCH SHIFT

The A40 Series is a heavy-duty, 10-bolt clutch shift PTO. Its solenoid valve uses a Deutsch connector for reliability in high-vibration environments, and it has a rotatable pump flange, precision-ground gears, internal pressure lube, and tapered roller bearings. The A40 also features a small envelope, making it ideal for applications with space limitations and resulting in easier installation overall.

This PTO is ideal for fire trucks, refuse trucks, feed mixer trucks, and cranes.

Part number example: A40-A10**-HX3X4PX

A50 SERIES: CONSTANT DRIVE

The A50 Series is a heavy-duty, 10-bolt constant drive PTO with similar ratings to the A40. It can power large variable displacement hydraulic pumps, refuse pumps, and other high-torque-driven equipment, and it works as an alternative to a front engine PTO.

It suits refuse trucks, cranes, snow and ice equipment, and concrete mixers.

Part number example: A50-A10**-MX3X4PX

EX DRIVE SHAFT EXTENSION CAPABILITY

The EX Drive is designed to fit Allison 3000 and 4000 Series transmissions with a retarder or cooler. It allows large gear or piston pumps to be direct mounted, eliminating driveline installations.

This shaft extension delivers maximum PTO torque and is available for the A20, A30, A40, and A50 Series.

MUNCIE START® COMPATIBLE

The A20 Series and A40 Series PTOs are compatible with the Muncie Start. The Muncie Start is recommended for applications that require high startup torque for high-inertia loads.

The Muncie Start eliminates torque spikes through the power take-off, truck drivetrain, and mounted auxiliary equipment upon startup, resulting in increased life of the power take-off and driven mechanical components. The PTO option also prevents engine stalls at low engagement RPM. 

Common applications include blowers, vacuum pumps, water pumps, compressors, and generators.

Start configuring the best PTO fit for your Allison 3000 or 4000 Series [link to builder here]