Usage:
785 And 789 Trucks
Description of Change: The intermediate cylinders in the hoist cylinder groups on 785 and 789 Trucks have been changed to cylinder assemblies. Formerly, the intermediate cylinders were one piece. The improved cylinder assemblies include four pieces. The head, tube, ring, and seal. The head and tube are threaded together with a ring and seal between. See the illustration.
Location of new components in hoist cylinder groups.
Adaptable To: The part numbers of the intermediate cylinders have not changed. The 4T5933 Cylinder Assembly is used in the 4T5931 Telescoping Hoist Cylinder on 785 Trucks. The serviceable components of the improved 4T5933 Cylinder Assembly include 3J8466 Ring (3) and 8F6230 Seal (4).
The 4T6047 Cylinder Assembly is used in the 9T2807 Telescoping Cylinder Group on 789 Trucks. The serviceable components of the improved 4T6047 Cylinder Assembly include 3J2688 Ring (3) and 1T0132 Seal (4).
Use the procedure that follows to assemble the improved intermediate cylinder assemblies.
1. Install seal (4) and ring (3) in the groove in head (2). The illustration shows the correct position of the seal and ring.
2. Apply either 7M7456 Bearing Mount or 9S3265 Retaining Compound to the threads inside tube (1).
3. Screw head (2) into tube (1) until only three threads on the head are exposed.
4. Apply 5P3413 Pipe Sealant to the exposed threads on the head. Screw the head the rest of the way into the tube.
5. Use a pin type spanner wrench to tighten the head to a torque of 600 ± 130 N·m (440 ± 95 lb ft.)