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  • A20 Series Pto A Robust Medium Duty Pto Featuring A New Rotatable Flange

A20 Series PTO: A robust, medium-duty PTO featuring a new rotatable flange

March 01, 2021
Andrew Dawson – Manager of Marketing & Advertising

In the world of power take-offs (PTOs), sometimes the smallest change can have a significant impact. The space to install a PTO is crowded and uncomfortable. Oftentimes, the space is too small to easily fit the PTO and hydraulic pump due to frame rail or other components that may cause interference.

Continual mindfulness of the installation process is important to be able to find ways to make it easier on installers as well as add flexibility to what can be mounted to a PTO.

Jim Abbott, product manager, and Kirk Williams, design engineer II, wanted to provide customers more flexibility with the pump mounting flange on the PTO. They learned customers often need to rotate the flange to allow mounting of the hydraulic pump and, in the past, this has been a cumbersome task. With this in mind, they developed the concept of allowing customers to order PTOs with the flange set with a specific position, or even ship it loose, so they can easily position it as needed.

This new idea was integrated into the new, robust A20 Series PTO which is designed specifically for applications with an Allison 3000 or 4000 Series transmission. The A20 Series PTO is rated for a single intermittent and continuous torque rating of up to 415 lbs.ft., and is the ideal PTO solution for class 7–8 trucks with automatic transmissions.



While the first priority is developing a robust PTO unit that can withstand the rigors of everyday use and effectively handle applications with higher torque ratings, there is an additional emphasis on the installation process.

“The main benefits are 30 unique mounting positions (every 6 degrees), no disruption of seals or shims during adjustment, and ability to order custom flange positions, or [order it] loose,” said Abbott.

It’s pretty simple to rotate the new flange: Remove the four bolts and metal ring, then rotate the flange to the ideal position. The example below represents the B2 position code, as the letter B is centered within the two dots.


If you have multiple trucks that will require the PTO to have the same position code you can easily match the desired arrangement before continuing installation.

RELATED: 6 easy steps to rotate the flange on the new A20 Series PTO

Or if you know you’ll be ordering PTOs with the same arrangement, you can order a PTO with the specific position code. Simply add the position code to the end of the A20 PTO part number and the flange will be set and shipped to your preferred arrangement.


These unique position codes will also allow you to save time down the road.

“The shape of the housing is the biggest improvement, versus legacy products,” said Abbott. “We have designed the housing to provide as much clearance as possible to the mounting fasteners.”

Beyond the unique flange, there were other areas of focus to make installation easier.

The A20 is compatible with
numerous gear pumps.


In addition to the improved clearance for the mounting fasteners, the cap screws are a bit longer (33mm instead of 30mm). While the 30mm cap screws offered satisfactory performance, they were lengthened to 33mm to take full advantage of the threads provided on the transmission. The external hoses have also been removed, so customers no longer have to work around them when installing. Over several years, Muncie Power Products engineers have developed an installation tool kit, containing all the tools needed to properly install the PTO.

“We developed the tool kit to allow an installer to get everything they need for a PTO installation in one place,” said Abbott. “This kit has been developed and refined by Muncie Power over the past several years, and we wanted to make it easy for the customer.”

It contains a torque wrench (optional), tool bag, and all the tools needed to properly install the PTO. This tool kit can be ordered as a separate part number.

The A20 presents numerous key features that make this a robust, long-lasting PTO. Features like proven clutch pack and solenoid technology, tapered roller bearings to increase PTO life, increased output shaft diameter for higher durability, and maximized gear design for noise reduction allow this PTO to have industry leading torque ratings for a medium-duty, clutch-shift PTO and provide improved durability.

The A20 PTO is suited for essentially any application utilizing the Allison 3000 and 4000 Series transmissions including dump, fire and rescue, refuse, utility, tow and recovery, snow and ice, and bulk hauling, among others.







The A20 is compatible with the Muncie Start—an electronically controlled, modulated clutch engagement system that eliminates torque spikes and allows for a smooth engagement of the PTO.
Use shift codes SX (Muncie Start 12VDC Integral) or SR (Muncie Start 12VDC Remote Mount).



The EX Drive is designed to fit on Allison 3000 and 4000 Series transmission to allow gear or piston pumps to be direct mounted, and is compatible with the A20 Series PTO.


ready to spec out your a20?