Usage:
Pinion Preload Adjustment
1. Install bearing cups (10) and (13) in housing (12). Bearing cups must be against (seated) the shoulders in housing (12).
2. Install bearing cone (9) on pinion (8). Bearing cone (9) must be against (seated) the shoulder on pinion (8). Lubricate bearing cone (9).
3. Install pinion (8) in housing (12). Press bearing cone (14) into place leaving a small amount of endplay. Lubricate bearing cone (14). Lubricate and install washer (15) and nut (16).
NOTE: Cup freezing or cone heating may be used if cups or cones are reset with a driver or press after parts have reached a uniform temperature. Limit cone heating to 135°C (275°F) maximum for a maximum of 4 hours. Lubricate bearings after they have cooled to prevent rusting.
4. Position the assembly vertically in a soft jawed vise. Tighten the vise against the teeth on pinion (8). Tighten an appropriate bolt and nut through an outer bolt hole in pinion housing (12).
5. Place a 203 mm (8.0 in) torque wrench on this bolt so that it is in line with the center of pinion (8).
6. While turning housing (12) with the torque wrench, tighten nut (16) until the torque wrench reading in the following chart is reached.
Check to be sure that there is zero end play of pinion shaft (8).
7. If pinion rolling torque exceeds the specification, back off nut (16) one-eighth turn and reseat bearing cone (14) and washer (15) against nut (16). Perform Steps 5 and 6 again.
If any other length torque wrench is used, find the torque wrench reading by using the following formula
Where:
"C" is the reading on the torque wrench (in N·m).
"B" is the length of the torque wrench (in meters).
"A" is the bolt circle radius (A) of pinion housing (12) in meters and is equal to .105 m (4.1 in).
"T" is the rolling torque specification for pinion bearing preload which is 0.7 to 1.1 N·m (6 to 10 lb in).
8. When the torque needed to turn the pinion is correct, stake nut (16) by peening the collar on the nut into the key slot in pinion shaft (8), see Illustration A for the correct tooling and dimensions.
NOTE: The nut may be reused if the collar is not cracked during removal or restaking.
Illustration A
Differential Backlash and Bearing Adjustment
NOTE: The following procedure controls bearing preload and gives the same results for used and new bearings.
1. Assemble the differential group (17).
2. Heat bevel gear (18) to 135°C (275°F) for a maximum of four hours. Install the bevel gear on the differential group and washer face of the bolts and torque 20 bolts (16) to 95 ± 10 N·m (70 ± 7 lb ft), then turn an addition 180° ± 5°. Check to make sure the bevel gear is seated on the differential group shoulder.
3. Press bearing cone (23) on bevel gear (18) and bearing cone (5) on differential case (17). Check for full seating of the cones.
NOTE: Cup freezing or cone heating may be used if cups or cones are reset with a driver or press after parts have reached a uniform temperature. Limit cone heating to 135°C (275°F) maximum for a maximum of 4 hours. Lubricate bearings after they have cooled to prevent rusting.
4. Remove intermediate housing (1) from center housing (26).
5. Install bearing cups (3) and (21), bearing sleeves (2) and (20) and two pins (7) and (25). Lubricate the threads of adjusting nuts (6) and (24) and install them in intermediate housing (1) and center housing (26).
6. Position center housing (26) in an appropriate support fixture with the open side facing upward. With a lifting device, lower differential group (17) and bevel gear into position in the center housing.
7. Install intermediate housing (1) on center housing (26). Install three bolts.
8. Lubricate and install O-ring seal on pinion housing (12). Install pinion housing (12) on center housing (26). Torque eight bolts to 120 ± 20 N·m (88 ± 15 lb ft). Use the original thickness of shims (11) or a new shim pack measured to the same thickness as the original pack. If the original shim pack is not available, use 70% of a new shim pack.
NOTE: Shim pack thickness may have to be changed when adjusting the tooth contact pattern.
9. Reposition center housing (26) in the support fixture so that center housing (26) and pinion housing (12) are horizontal (the same position as they are in the machine).
10. Tighten adjusting nuts (6) and (24) to a position that maintains gear backlash (but not tight gear mesh) and a slight bearing end play.
11. Measure the torque required to rotate pinion shaft (8). Record the measured torque. Use a 5P0954 socket on pinion shaft nut (16) for this measurement.
12. While rotating pinion shaft (8) back and forth tighten adjusting nut (24) to zero backlash position. Then back off adjusting nut (24) 20° plus the increment to the nearest lock position.
13. Tighten adjusting nut (6) while rotating pinion shaft (8). Tighten nut (6) until a torque increase of 0.2 to 0.6 N·m (2.0 to 5.0 lb in) over the torque recorded in Step 11 is measured. This is the seated position.
14. Tighten adjusting nut (6) 40° plus the increment to the nearest lock position.
NOTE: As a check for correct assembly and adjustment, the rolling torque of the bevel gear group measured at the pinion shaft should be 1.8 to 3.0 N·m (16 to 27 lb in) for new bearings and .9 to 1.5 N·m (8 to 13 lb in) for used bearings.
15. Measure the backlash between bevel gear (18) and pinion shaft (8). The backlash must be 0.20 +0.10 -0.08 mm (.008 +.004 -.003 in). Perform this through the inspection hole with a dial indicator on the heel of a bevel gear tooth.
NOTE: Backlash may also be measured at the pinion shaft. The measurement can be performed by placing a dial indicator (as shown) tangent to the spline. Make sure the yoke or spline adaptor is tight to the spline.
Pinion Shaft Spline (backlash measurement)
(A) Distance of dial indicator from pinion centerline.
16. The following chart gives examples of backlash at the pinion shaft, by showing the different distances from the pinion centerline to the dial indicator:
17. If the backlash does not meet specifications, loosen one nut the same amount as the opposite nut is tightened. This will maintain the bearing preload.
Checking Pinion And Bevel Gear Tooth Contact
Illustration A
1. After the backlash and preload adjustments have been made, the tooth contact between pinion shaft (8) and bevel gear (18) must then be checked. Perform the procedure that follows:
a. Put a small amount of Prussian blue, red lead or paint on three or four adjacent teeth of bevel gear (18) through the access hole in center housing (26).
b. Rotate pinion shaft (8) several revolutions in one direction and then several revolutions in the opposite direction. Then turn pinion shaft in one direction until the marked teeth can be seen through the access hole.
c. The correct area of tooth contact starts near the inside end of the teeth of bevel gear (18) and goes a maximum of 50 percent of the length of the teeth. See Illustration A for an example of the correct area of tooth contact.
Illustration B
2. If the tooth contact looks like the marks in Illustration B, perform the procedure that follows:
a. Remove some of shims (11).
b. Perform Steps 15 and 17 for Backlash Adjustment Procedure again.
c. Perform Step 1 of Checking Pinion And Bevel Gear Tooth Contact again.
Illustration C
3. If the tooth contact looks like the marks in Illustration C, perform the procedure that follows:
a. Add some of shims (11).
b. Perform Steps 15 and 17 for Backlash Adjustment Procedure again.
c. Perform Step 1 of Checking Pinion And Ring Gear Tooth Contact again.
NOTE: Always make sure the backlash adjustment is correct before an adjustment is made to the area of tooth contact. Several adjustments to the backlash and tooth contact may be necessary to get the correct adjustments. Always remember that a change to gear clearance (backlash) will also change the gear contact. A change in gear contact will also change gear clearance (backlash).
4. After adjustments are made, remove the Prussian blue, red lead or paint from the gears.
5. Install bolts (4) and (22) with lock on each adjusting nut (6) and (24). Tighten bolh bolts and bend locks.
Axle Housing Assembly And Bearing Preload Adjustment
1. Freeze ring gear (1) and press into axle housing (2) with chamfer side of ring gear toward the axle housing. Check for full seating of the ring gear against the housing shoulder.
2. Press bearing cups (4) and (6) into housing and check for full seating of bearing cups against housing shoulders.
3. Press bearing cone (7) on axle (9) and check for full seating of cone against the axle shoulder. Lubricate the cone roller assembly.
4. Install Duo-Cone seals (8) to both axle (9) and housing (2).
NOTE: Rubber toric seals and all surfaces in contact with them must be clean and dry at assembly. Put a thin layer of oil on the surfaces of the metal seals that are in contact just before installation. The metal seal must be assembled square with the bore, and the rubber toric seals must not be bulged or twisted.
5. Secure axle (9) in a vertical position with the rim flange down.
6. Lower housing (2) over the axle.
7. Press bearing cone (5) onto axle (9) with endplay remaining in the bearing. Lubricate the cone roller assembly.
8. Lubricate and install adjusting nut (3). Tighten the nut until only a small amount of endplay remains in the axle/bearing assembly.
9. Measure the torque required to rotate housing (2). This is the seal drag torque. To do this, tighten an appropriate bolt and nut through an outer bolt hole in axle housing (2). Place a 203 mm (8.0 in) torque wrench on this bolt so that it is in line with the center of axle shaft (9). While turning housing (2) with the torque wrench, note the reading on the torque wrench and calculate the actual seal drag torque with the following formula:
Where:
"SDT" is the actual seal drag torque (in N·m)
"C" is the reading on the torque wrench (in N·m).
"B" is the length of the torque wrench (in meters).
"A" is the bolt circle radius of axle housing (2) in meters.
Bolt circle radius for oscillating axle ... .175 m (6.7 in)
Bolt circle radius for fixed axle ... .19 m (7.5 in)
10. While turning housing (2) with the torque wrench, tighten nut (3) until the torque wrench reading calculated with the following formula is reached.
Where:
"C" is the reading on the torque wrench (in N·m).
"B" is the length of the torque wrench (in meters).
"A" is the bolt circle radius of axle housing (2) in meters.
Bolt circle radius ... .175 m (6.7 in)
"T" is the rolling torque specification for axle bearing preload.
Rolling torque:
New bearings ... 3.8 to 5.0 N·m (34 to 44 lb in)
Used bearings ... 1.9 to 2.5 N·m (17 to 22 lb in)
"SDT" is the actual seal drag torque (in N·m) from Step 9.
Check to be sure that there is zero end play of axle shaft (9).
11. If axle bearing preload rolling torque exceeds the specification, back off nut (3) one-eighth turn and reseat bearing cone (5) against nut (3). Perform Step 10 again.