Replacing an Electric PTO Clutch

When replacing an Electric PTO Clutch, it must have an exact replacement (i.e. rotation, ft. lb. rating, and configuration). Clutches are specific to their application. The following criteria will help ensure successful clutch installation.

Torque: Clutches are designed according to the engine’s torque rating in ft. & lbs. As a rule of thumb, the higher the horsepower, the higher the torque rating. PTO clutches are rated 60,80,125,150,175,200 (ft-lb) torque. A clutch rated at 60 (ft-lb) would not last on a 20 HP Engine.

Pulley: The pulley diameter and width are important for belt life and performance. The diameter is very critical. If a larger diameter pulley is used, the blade tip speed is increased, making the deck parts run faster than they were designed to run. Incorrect pulley selection can be dangerous and may shorten the parts life.

Rotation: Direction of rotation is another aspect to take into consideration. PTO clutches are designed to run in one direction only. Two clutches that look alike may be mounted on the engine differently. When the pulley is closest to the engine, or if the pulley is mounted away from the engine, the internal clutch rotation changes.

Do’s and Don’ts of Electric PTO Clutches

Do: Burnish (Initial Break-in) a new clutch whether it’s a new replacement or on a new machine. With mower deck attached and no other load, run the engine at half throttle. Then, engage and disengage the clutch 5 times (10 seconds on / 10 seconds off). Repeat at 75% throttle, (10 seconds on / 10 seconds off).

Don’t: Wash or let a clutch get wet. Water is detrimental to the bearing. If the clutch does get wet, run for at least 5 minutes disengaged.

Do: Start and stop the clutch at a lower RPM. This will insure less slippage (equals less heat) upon engagement and less braking friction when the clutch comes to a stop. This practice also enhances belt longevity.

Don’t: Allow electrical connections, especially the ground circuit, to corrode. Make sure there are good, corrosion free connections. PTO clutches require 12 volts to operate properly. Less voltage allows PTO clutches to slip and may prevent engagement.