Medium Duty: Transmission and PTO Upkeep

Maintaining transmissions and PTOs is serious business.


Manuals—other than needing fluid levels checked and possibly changed once— are basically trouble-free, Johnson says, but there are still things to watch out for.

“I would suggest to periodically pop the plug out and check for excessive build-up,” he says. “And always be sure the clutch is working properly and fully releasing.”

Technicians doing routine service on transmissions or PTOs should always test-drive the vehicle afterwards to check for unusual noises. Johnson says even equipment right from the dealer or factory should be thoroughly examined before going into service.

“One of the most critical things with any transmission equipped with a PTO when you first put it into service is to make sure it’s right, and if it’s not right when you put it in service, you can guarantee you’re going to have problems—not installed properly, not shifting properly, not adjusted properly—and just because it came from the dealer or the factory, that’s not a 100 percent guarantee it’s going to be installed properly,” he says.

Lastly, technicians who maintain vehicles that operate in dirty conditions need to watch for dirt around the transmission, Johnson says, particularly if they have a PTO with a mechanical shift mechanism or an external pneumatic shifter.

“Dirt packed in around the transmission will impede cooling, because you get cooling from the surface of the transmission,” he says. “On an off-road vehicle—especially one with a skid plate—you want to clean the dirt from the skid plate to make sure the transmission is cooling properly. The rest is just good common sense.”

SAFETY FIRST

These days, maintaining transmissions and power take-offs is one of the less-complicated jobs your technicians are going to be faced with. Keep the coolant and filters fresh, and keep up with your PM schedule, and your fleet should be running smoothly down the road.

Still, with the potential for grave injury or death when fixing malfunctioning power take-offs, safety must always be the first concern in your shop and needs to be stressed at all times, particularly with inexperienced technicians. Don’t take any chances.

Perhaps Muncie Power Products’ Douglass put it best:

“We tell people the first step in working on a power take-off is to take the keys out of the ignition and put them in your pocket.”

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