MAST A 0320512 - Caterpillar

Note: The measurement for backlash should be made at the base of the gear teeth on the bevel gear. If access to the gear teeth is not possible, the backlash can be measured at the spline of the pinion shaft. In order to measure the backlash at the spline of the pinion shaft, place a dial indicator tangent to the spline on a flat surface of a drive shaft yoke or of a spline adapter. In order to obtain an accurate measurement, make sure that the yoke or the adapter is tight to the spline of the shaft. If a yoke or an adapter is not available, a strip of steel can be attached to the spline. The strip of steel and the dial indicator are shown in illustration 2. When you measure the backlash from the spline of the pinion, use the following formula to calculate the proper measurement at the dial indicator: The actual backlash measurement is equal to the dial indicator reading that is divided by the dimension "A".The measured backlash is 0.09 to 0.13 mm (0.0035 inch to 0.0051 inch).
Illustration 1 g00797559
Measuring Pinion Backlash
Install tooling (A). Position the contact point (plunger) at 90 degrees to one of the bevel gear teeth. Adjust the dial indicator so that the contact point (plunger) is just in contact with the tooth. Zero the dial indicator. Hold the pinion gear stationary and rotate the bevel gear back and forth in order to measure the backlash. The bevel gear backlash is the total deflection of the dial indicator.
Illustration 2 g01047356
Measure the bevel gear backlash.The assembled backlash for the spiral bevel gear ... 0.09 to 0.13 mm (0.004 inch to 0.005 inch)
Illustration 3 g01163148
(1) 268-1094 Bearing Retainer for the limited slip differential (1) 249-8004 Bearing Retainer for the open differential (2) 254-0333 Shim Pack (3) Bevel Gear (4) Pinion Shaft (5) 249-8027 Housing for the rear axle (5) 268-1089 Housing for the front axle (6) 254-0334 Shim Pack (7) 268-1093 Bearing Retainer
If the measurement is not within the specification, transfer a proper thickness of shims (2) from the bearing retainers (1) and (7) from one side to the other side. If the backlash is greater than 0.13 mm (0.005 inch) move the ring gear toward the pinion gear. If the backlash is less than 0.09 mm (0.004 inch) move the bevel gear (3) away from the pinion gear (4) .Note: Do not change the total thickness of the shims..
Check the tooth contact pattern.Checking the Tooth Engagement
Illustration 4 g01163148
(1) 268-1094 Bearing Retainer for the limited slip differential (1) 249-8004 Bearing Retainer for the open differential (2) 254-0333 Shim Pack (3) Bevel Gear (4) Pinion Shaft (5) 249-8027 Housing for the rear axle (5) 268-1089 Housing for the front axle (6) 254-0334 Shim Pack (7) 268-1093 Bearing Retainer After the pinion preload adjustments have been made, check the tooth contact between the pinion shaft (4) and the bevel gear (3) .
Put