BEARING KIT 9N8207 - Caterpillar

Table 1
Required Tools
Part Number Description Quantity
1U-6690 Socket Wrench Assembly 1
Measure the torque that is needed to rotate pinion shaft (6). Record this torque. For this measurement, use a 1U-6690 Socket Wrench Assembly on pinion shaft nut (13).
While you rotate pinion shaft (6) back and forth, tighten adjusting nut (20) to the zero backlash position. Then back off adjusting nut (20) by a value of 20° plus the increment to the nearest lock position.
Tighten adjusting nut (4) on the bevel gear group while you are rotating the pinion shaft. Tighten nut (4) until the overall preload rolling torque that is measured at the pinion shaft is 4.5 N m to 6.8 N m (40 lb in to 60 lb in). Note: When you check for correct assembly and for correct adjustment, measure the rolling torque of the bevel gear group at the shaft of the pinion. For new bearings, the rolling torque should be 4.5 to 6.8 N m (40 to 60 lb in). For used bearings, the rolling torque should be 2.25 to 3.4 N m (20 to 30 lb in).
Measure the backlash between bevel gear (16) and pinion shaft (6). Measure the backlash at the heel of the bevel gear. The backlash must be 0.30 + 0.12 − 0.10 mm (0.012 + 0.005 − 0.004 inch). To measure the backlash, place a dial indicator tangent to the spline. Refer to Illustration 2 for an example. Make sure that the yoke or the spline adapter is tight to the spline.
Illustration 2 g00275111
Pinion Shaft Spline (backlash measurement)
(B) Distance of dial indicator from the centerline of the pinion.
Table 2 that follows lists examples of backlash at the pinion shaft. Table 2 shows the different distances from the centerline of the pinion to the dial indicator.
Table 2
Examples of Backlash at Pinion Shaft
Dimension (B) Nominal Backlash Maximum Backlash Minimum Backlash
50 mm (2 inch) 0.28 mm (.011 inch) 0.40 mm (.016 inch) 0.18 mm (.007 inch)
100 mm (4 inch) 0.57 mm (.022 inch) 0.80 mm (.032 inch) 0.35 mm (.014 inch)
150 mm (6 inch) 0.86 mm (.034 inch) 1.20 mm (.047 inch) 0.53 mm (.021 inch)
200 mm (8 inch) 1.15 mm (.045 inch) 1.60 mm (.063 inch) 0.70 mm (.028 inch)
If the backlash does not meet specifications, loosen one adjusting nut and tighten the opposite adjusting nut by the same amount. This procedure will maintain the bearing preload. Pinion and Bevel Gear Tooth Contact Check
Illustration 3 g00103470
After the differential backlash adjustments and pinion preload adjustments have been made, tooth contact between pinion shaft (6) and bevel gear (16) must be checked. Perform the procedure that follows:
Apply small amount of Prussian blue, of red lead, or of paint on three adjacent teeth or on four adjacent teeth of bevel gear (16).
Rotate pinion shaft (6) for several revolutions in one direction. Then rotate pinion shaft (6) for several revolutions in the opposite direction. Then turn the pinion shaft in one direction