5-42. REAR TANDEM AXLE AND DIFFERENTIAL-Continued
(9) Adjust bearing preload as follows:
(a) Using a press, install the drive pinion (18) and bearing cage assembly (28), gear head down, on a
(b) Install a sleeve of the correct size against the inner race of the outer bearing.
(c) Apply pressure of 30,000 lb (9979 kg) to the pinion bearings. While pressure is held, wind a cord
around the bearing cage (28) several times.
(d) Attach a spring scale to the end of the cord. Pull the scale, with cord attached, in a horizontal line.
As bearing cage (28) rotates, read value indicated on scale.
Do not read starting torque. Read only the torque value after
the cage starts rotating. Starting torque will give a false reading.
(e) Measure the diameter of bearing cage (28) where cord was wound. Divide the dimension in half to
get the radius dimension. Make a note of the radius dimension. Calculate the bearing preload as
(f) Use the following calculations as an example:
1. Reading from spring scale-7.5 lb. (3.4 kg).
2. Diameter of bearing cage-6.62 in. (16.8 cm).
3. Radius of bearing cage-3.31 in. (8.4 cm).
4. 7.75 lb. x 3.31 in. = 24.8 lb. in.-preload.
(g) Preload should be 5 to 45 lb in. If preload is not within this range, disassemble the bearing cage
(28) and change the spacer (26) (see 5-42. b. steps 25-28). To increase the preload, install a
thinner spacer. To decrease the preload, install a thicker spacer. After changing spacer, check
preload as above to be sure preload is correct.