784B and 785B Off-Highway Truck/Tractors Power Train Caterpillar

Illustration 1	g00295770

(A) Dimension from the face of the sun gear to the machined face of the outer carrier ... 28 ± 2 mm (1.10 ± 0.08 inch)

(1) Torque for the six bolts that are on the shafts of the inner carrier ... 135 ± 15 N·m (100 ± 11 lb ft)

Note: Apply 9S-3263 Thread Lock to the threads of the bolts after the bearing adjustment has been made.

(2) 7I-5540 Shaft

Outside diameter of a new shaft ... 77.839 ± 0.012 mm (3.0645 ± 0.0005 inch)

Note: Measure the diameter at the contact point of the roller bearings.

(3) 8W-3072 Planetary Gear

Inside diameter of a new gear ... 136.436 ± 0.013 mm (5.3715 ± 0.0005 inch)

Note: Measure the diameter at the contact point of the roller bearings.

(4) Torque for the 12 studs ... 55 ± 10 N·m (41 ± 7 lb ft)

(5) 6G-6352 Planetary Gear

Inside diameter of a new gear ... 147.429 ± 0.020 mm (5.8043 ± 0.0008 inch)

Note: Measure the diameter at the contact point of the roller bearings.

(7) 8X-7165 Planetary Shaft

Outside diameter of a new shaft ... 101.661 ± 0.010 mm (4.0024 ± 0.0004 inch)

Note: Measure the diameter at the contact point of the roller bearings.

(8) Torque for four bolts ... 125 ± 8 N·m (92 ± 6 lb ft)

(9) Installation depth for four dowels ... 8.00 ± 0.10 mm (0.315 ± 0.004 inch)

(10) Torque for eight bolts ... 125 ± 8 N·m (92 ± 6 lb ft)

Note: Apply 7M-7456 Compound to the threads of the bolts.

(11) 8W-6910 Shim Pack

Shim pack thickness ... 1.24 mm (0.049 inch)

Note: See "Procedure To Install The First Reduction Planetary Components" in order to determine the amount of shims to use.

(12) Torque for four bolts ... 34 ± 7 N·m (25 ± 5 lb ft)

Procedure To Install The First Reduction Planetary Components

1. Assemble bearing assembly (14) and the snap ring into gear (3). Assemble gear (3) into inner carrier (13) .

2. Install 1U-5812 Plate, 1U-5813 Shaft, and two bolts (1) .

3. Tighten bolts (1) to 20 ± 5 N·m (15 ± 4 lb ft) and rotate gear (3) .

4. Again, tighten bolts (1) to 34 ± 3 N·m (25 ± 2 lb ft) and rotate gear (3) .

5. Again, tighten bolts (1) to 34 ± 3 N·m (25 ± 2 lb ft) but DO NOT rotate gear (3) .

6. Use a depth micrometer and measure the gap between 1U-5812 Plate and 1U-5813 Shaft.

7. The shim pack thickness is the gap that was measured in Step 6 plus 0.323 + 0.000 - 0.030 mm (0.0127 + 0.0000 - 0.0012 inch).

8. Remove 1U-5812 Plate and 1U-5813 Shaft .

9. Verify that the new 7I-5540 Shaft (2) and the 1U-5813 Shaft are the same length. If there is a difference in length of the shafts adjust the shim pack thickness that was found in Step 7.

   Note: If 7I-5540 Shaft (2) is longer than 1U-5813 Shaft then subtract the difference from the shim pack thickness that was found in Step 7. If 7I-5540 Shaft (2) is shorter than 1U-5813 Shaft then add the difference to the shim pack thickness that was found in Step 7.

10. Use a press in order to install shaft (2). Make sure that all of the components are aligned and that all bearing components are seated. Use a maximum force of 356 kN (40 tons) to install the shaft.

11. Install shim pack (11), plates (6) and bolts (1). Torque bolts (1) to 135 ± 15 N·m (100 ± 11 lb ft).

12. If no gap exists between plate (6) and carrier (13) then press shaft (2) into the bore until there is a slight gap.

13. Again, torque bolts (1) to 135 ± 15 N·m (100 ± 11 lb ft).

14. Use a brass drift to drive plate (6) toward carrier (13) in order to close the gap. Verify that gear (3) rotates with slight resistance when the gear is rotated by hand.

Procedure To Install The Second Reduction Planetary Components

Illustration 2	g00453386

1. Install the retaining ring (20) on each shaft (21) .

2. Put spacer (17) in the center of gear (15). Put one bearing (18) in position on each side of spacer (17) .

3. Put thrust washer (19) on each side of gear (15). Put gear assembly into outer carrier (30) .

4. Install shaft (21) through gear assembly.