776D, 777D and 777D HAA Off-Highway Truck/Tractors Suspension Cylinder Caterpillar

Illustration 1	g01120275

Illustration 2	g01146822

Note: When you assemble suspension cylinder, you must fill the cylinder with the proper amount of oil. Refer to the Testing and Adjusting, "Suspension Cylinder Oil Requirements" for the correct initial fill. See the Testing and Adjusting, "Suspension Cylinder (Front) - Purge and Charge" for the charging procedure and for the charging dimensions.

Note: The front suspension cylinder must be assembled in the vertical position.

(A) Outside diameter of piston (two places) ... 271.78 ± 0.13 mm (10.700 ± 0.005 inch)

(B) Inside diameter of tube ... 273.05 + 0.13 - 0.05 mm (10.750 + 0.005 - 0.002 inch)

(C) Inside diameter of gland (three places) ... 229.000 ± 0.030 mm (9.0157 ± 0.0012 inch)

(D) Outside diameter of rod ... 228.52 ± 0.05 mm (8.997 ± 0.002 inch)

(1) Use 116-2673 Shims as shims are required.

(2) 175-3184 Valve

Torque for the charging valve ... 50 ± 10 N·m (37 ± 7 lb ft)

Torque for the valve cap ... 4.25 ± 0.85 N·m (38 ± 8 lb in)

(3) Install the cap so that the lockring is down.

(4) Torque for 16 nuts ... 1175 ± 50 N·m (865 ± 35 lb ft)

(5) 9D-1842 Shim Pack ... 4.47 ± 0.08 mm (0.176 ± 0.003 inch)

Note: See the Machine System Disassembly and Assembly, "Spindle (Front) - Install" in order to determine the thickness that should be installed.

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Personal injury or death can result when working with the strut rod. Sudden release of the spindle from the strut rod or the snapping of a bolt when removing the plate can result in injury. Loosen all bolts one-half turn, working around the plate in a circular pattern. Perform this again and again until the torque is released for the bolts.

(56) Bolts

Preliminary torque for six bolts ... 205 ± 25 N·m (150 ± 18 lb ft)

Final torque for 18 bolts ... 1090 ± 35 N·m (800 ± 25 lb ft)

Note: See the Machine System Disassembly and Assembly, "Spindle (Front) - Install" before you install these bolts.

(7) Torque of 20 bolts

Static inspection torque of 20 bolts ... 200 N·m (148 lb ft)

Note: Refer to Specifications, RENR3130, "Torque Specifications" for the standard final assembly torque value for the 20 bolts.

(8) Apply 8T-9014 Silicone Sealant prior to assembly.

(9) Fill the lower cavity with 7X-7664 Grease after assembly.

(10) Apply a coat of 4C-5593 Anti-Seize Compound to the taper before assembly with the spindle.

(11) Apply 8T-9014 Silicone Sealant to the 6H-1717 Bolt prior to assembly. Torque the bolt by hand. The amount of torque should not cause the end to turn.

The charging medium for suspension cylinder is dry nitrogen.

Internal volume ... 13 L (795 in³)

Charged pressure ... 1520 kPa (220 psi)

Service pressure ... 5300 kPa (770 psi)

Bursting pressure ... 41600 kPa (6000 psi)

Charged safety factor ratio ... 27.3:1

Service safety factor ratio ... 7.8:1