The shaft drive is a six splined, 1 3 / 8 " diameter unit, driven through two helical gears, mounted in a housing attached to the vehicle at the center of the frame rear crossmember. Both the input and output shafts rotate on tapered roller bearings, with the running clearance adjusted by shims.
At the maximum engine torque speed, 2,000 rpm, the PTO output shaft speed is 536 rpm, which is the SAE standard for farm tractors. Refer to he accomapnying chart to aid in the selection of engine speeds and gear ratio positions.
REMOVAL & INSTALLATION
- Matchmark and disconnect the rear U-joint from the companion flange.
- Remove the attaching screws and remove the flange.
- Unbolt and remove the shift drive assembly from the truck.
- Drain the unit and clean the exterior.
- Remove the input shaft cover and gasket, bend the locking tabs away from the nut and remove the input shaft nut and washer.
- Remove the bearing retainer and gasket, the bearing, the shims and bearing cone. Remove the bearing cup and snapring.
- Remove the oil seal retainer and pilot assembly.
- Press the shaft through the housing, removing the bearing cone, oil seal and seal retainer. Remove the gear through the rear bearing opening. Push out the bearing cup and snapring.
- Follow steps 5 through 8 to disassemble the output shaft.
- The tapered roller bearings on both shafts are adjusted by shim packs placed between the gear hubs and bearing cones. The shims are interchangeable, but, if you are reusing shims, don't mix them. Replace them in their original positions. If new parts are being installed, new shims will probably be necessary. Enough shims should be used to allow for free rotation of all parts with no end-play. If the necessary shim thickness is not known, install 0.031" shims to each shaft and add or remove shims as necessary.
- Assembly and installation is the reverse of removal and disassembly.