- Off-Highway Truck:
- 797 (S/N: 5YW1-UP)
- 797B (S/N: JSM1-UP)
Description of Change: The slip joint group is part of the drive shaft group. Due to the weight of the slip joint group, the drive shaft group must be balanced.
Additional machining of material on the yokes, new, tighter tolerances for the balance of the drive shaft group and counterweights are now used to help balance the drive shaft.
The updated manufacturing process will help prevent vibration that causes the following problems.
- The drive shaft U-joints will break.
- The bolts in the drive shaft group will break.
- The lubrication in the spider and bearing assembly will leak from the unit.
- The bearings in the spider and bearing assembly will be damaged.
 | |
| Illustration 1 | g01842973 |
A typical drive shaft | |
 | |
| Illustration 2 | g01842976 |
A view of area (A) | |
The updates to the manufacturing process for the slip joint group have caused the drive shaft group to be manufactured with a serial number (1). When you report the failure of a drive shaft group, you should inspect the drive shaft for a serial number. Include the serial number of the drive shaft if the serial number is on the part.
Adaptable To: The updated 255-0775 Slip Joint Gp is adaptable to machines 5YW1-UP and JSM1-418. The updated slip joint group became effective in production with the machine JSM419-UP.