2009/09/30 Caterpillar

Off-Highway Truck/Tractor:

770 (S/N: BZZ1-UP)

772 (S/N: RLB1-UP)

773D (S/N: NBJ1-UP)

773E (S/N: ASK1-UP)

773F (S/N: EED1-UP)

777D (S/N: AGC1-UP; FKR1-UP)

777F (S/N: JRP1-UP)

785C (S/N: APX1-UP)

789C (S/N: 2BW1-UP)

793D (S/N: FDB1-UP)

797B (S/N: JSM1-UP)

Quarry Truck:

775F (S/N: DLS1-UP)

Description of Change: A system that utilizes dual shocks is now standard on certain Off Highway Trucks.

Adaptable To: The dual shocks are used with the 199-5725 Seat Suspension Gp and 199-5727 Seat Suspension Gp. The dual shock suspension groups feature a 212-7779 Shock Absorber Kit that contains a standard capacity adjustable shock and a 192-7848 Shock Absorber Kit that contains a standard capacity fixed shock.

The dual shocks are now standard on the following machines:

• 770 (S/N: BZZ508-UP)

• 772 (S/N: RLB557-UP)

• 773D (S/N: NBJ422-UP)

• 773E (S/N: ASK108-UP)

• 773F (S/N: EED1066-UP)

• 777D (S/N: AGC75003-UP; FKR462-UP)

• 777F (S/N: JRP2109-UP)

• 785C (S/N: APX1683-UP)

• 789C (S/N: 2BW1554-UP)

• 793D (S/N: FDB1162-UP)

• 797B (S/N: JSM484-UP)

• 775F (S/N: DLS1052-UP)

A shock with increased capacity can now be used as the second shock in a system that utilizes dual shocks. The 150-1550 Shock Absorber Assembly provides additional dampening for heavier operators or for extreme conditions. The Special Instruction, REHS2761 provides the assembly instructions for installing the second shock. The new shock will improve the quality of the ride and the new shock can reduce unwanted tightening of the seat belt.

Table 1

Description	Part Number	Part Name
Standard Capacity Adjustable Shock	212-7779	Shock Absorber Kit
Standard Capacity Fixed Shock	192-7848	Shock Absorber Kit
Increased Capacity Fixed Shock	150-1550	Shock Absorber Assembly

For additional training and diagnostic material, refer to the following publications.

• Special Instruction, REHS2761, "Installation Instruction for 212-7779 Shock Absorber Kit, 192-7848 Shock Absorber Kit, and 213-5170 Indicator Kit on Toggle Link Vertical (TLV) Seat Suspensions"

• Operator Instructional Video, PEVD5717, "Comfort Series Seat for Caterpillar Machines".