Ogura 2.75 Electric PTO Clutch

The Ogura GT2.75 electric PTO Clutch is mounted in the Mammoth 850 directed below the engine drive pulley and has a standard armature, rotor, and field coil. The armature engages the rotor when the PTO Switch is engaged, closing the air gap. This clutch also has dual brake plates that are reversible.

PTO Idler and Pulley

The PTO Idler and Pulley will place tension onto the PTO Belt with the idler spring in place. There is a square hole in the end of the idler bracket that allows a technician to insert a 3/8" extension into to help disengage the idler when the belt needs to be removed.

90 Degree PTO Gearbox Pulley

The cantilever style gearbox has two internal beveled spiral gears. Input from the engine to the pulley is at 3600 rpms with an output of 1165 rpms. This gives the gearbox a reduction ration of approximately 3:1. There are two tapered roller bearings for the input and output shafts.

Oil used for the gearbox is PAO220 (#00078300). A drain plug is accessible from the bottom of the gearbox while a vent/fill plug is accessible from the top.

Driveshaft and Coupler Sheave

The driveshaft is a major component of the PTO system on the Mammoth 850. It has a splined attachment system on the end that will allow for connection with the snowhead attachments as well as the brush attachments.

The driveshaft is connected to the right-angle gearbox’s output shaft by a coupler sheave. The coupler sheave will mount to the driveshaft and gearbox’s output shaft by two square keys and four set screws. These set screws have a torque value of 26.4 ft.-lbs.

If driveshaft removal is necessary, please see the driveshaft or PTO Assembly replacement procedures for proper installation of the coupler sheave and/or driveshaft.

Drivebelt and Remote Alternator

The drive belt is powered by the engine pulley secured to the crankshaft and is routed around the remote alternator and hydraulic pump. There is also a drive idler bracket and pulley to keep tension on the drive belt.

With the crankshaft spinning, the remote alternator’s pulley will turn and, with battery power at the sense and ignition terminals, will allow the remote alternator to produce power to recharge the battery, power the wire harness, and power the actuator contactors.

Further Information