- Articulated Truck:
- 725 (S/N: AFX1-UP; B1L1-UP)
- 730 (S/N: AGF1-UP; B1M1-UP)
- 730 EJECTOR (S/N: B1W1-UP)
- 735 (S/N: AWR1-UP; B1N1-UP)
Description of Change: New differential gears are used on the above listed machines. The new differential gears have improved bevel gear sets that provide a press fit to the outer pinion bearing. The diameter of the outer bearing surface on the pinion shaft was increased in order to provide the bearing with a press fit. The new pinion shafts with a press fit outer bearing will reduce the load on the locknut for the pinion shaft.
Adaptable To: The new differential gears contain improved bevel gear sets that reduce the load on the locknut for the pinion shaft. The new differentials have replaced the former differential gears in production and parts service. The new bevel gear sets have replaced the former bevel gear sets in production and parts service. All the part numbers of the new differentials, new bevel gear sets, former differentials and former bevel gear sets are listed in Table 1.
| Differentials and Bevel Gear Sets | ||||
|---|---|---|---|---|
| Model | Former Differential | Former Bevel Gear Set | New Differential | New Bevel Gear Set |
| 725 Front and Rear |
147-6790 | 147-7247 | 282-6916 | 279-4642 |
| 725 Center |
188-1406 | 147-7251 | 282-6915 | 279-4630 |
| 730 Front and Rear |
147-7380 | 147-6792 | 282-6918 | 279-4568 |
| 730 Center |
188-1408 | 147-6793 | 282-6924 | 279-4570 |
| 735 Rear |
175-0336 | 147-6792 | 282-6920 | 279-4568 |
| 735 Center |
152-4390 | 147-7385 | 282-6921 | 147-7385 (1) |
| ( 1 ) | No change in the Bevel Gear set |
The new differential gears are direct replacements for the former differential gears. The new bevel gear sets are a direct replacement to the former bevel gear sets.
When a new bevel gear set is installed into a new differential or a former differential, the following assembly information must be used:
Assembly of a New Bevel Gear Set in a Differential
ReferenceDisassembly and Assembly, RENR3448, "725, 730 and 730 EJECTOR Articulated Trucks Power Train", "Differential and Bevel Gear (Front and Rear) - Assemble".
ReferenceDisassembly and Assembly, RENR3448, "725, 730 and 730 EJECTOR Articulated Trucks Power Train", "Differential and Bevel Gear (Center) - Assemble".
ReferenceDisassembly and Assembly, RENR5138, "735 Articulated Truck Power Train", "Differential and Bevel Gear (Front and Rear) - Assemble".
ReferenceDisassembly and Assembly, RENR5138, "735 Articulated Truck Power Train", "Differential and Bevel Gear (Center) - Assemble".
- Raise the temperature of bearing cone (1) to a maximum temperature of 135 °C (275 °F). Use a 1U-8865 Infrared Thermometer in order to check the temperature of the bearing cone.
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| Illustration 1 | g01285285 |
- Install bearing cone (1) onto pinion shaft (2) .
Note: Do not reset bearing cone (1) at this time.
- Install washer (3) onto pinion shaft (2) .
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| Illustration 2 | g01285287 |
- Ensure that the input pinion bearings are adequately lubricated before installing new locknut (4) .
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| Illustration 3 | g01285324 |
- Install bolt (6) that is used to secure the output yoke into pinion shaft (2) .
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| Illustration 4 | g01285336 |
- Tighten locknut (4) against the washer. Rotate pinion shaft (2) several times. At the same time, tap the top of the pinion shaft with a soft mallet in order to ensure that the bearings are fully seated. It may be necessary to tap both ends of the pinion shaft in order to ensure that the bearings are seated fully.
- Continue to tighten locknut (4) until the rolling torque for pinion shaft (2) is approximately 2.25 N·m (20 lb in). Use 9S-7354 Torque Wrench (5) to measure the rolling torque. Rotate the pinion shaft several times while tapping the splined shaft end with the soft mallet until the rolling torque is maintained at 2.25 N·m (20 lb in).
- Loosen locknut (4) .
- Tighten locknut (4) again until the rolling torque is between 0.67 N·m (6.0 lb in) to 1.35 N·m (12.0 lb in). Rotate pinion shaft (2) several times. At the same time, tap the pinion shaft with the soft mallet until the rolling torque is maintained at 0.67 N·m (6.0 lb in) to 1.35 N·m (12.0 lb in).
Note: The torque that is specified is for new bearings. For used bearings, limit the applied torque to one-half of the specified torque 0.34 N·m (3.0 lb in) to 0.67 N·m (6.0 lb in).
- Recheck the rolling torque. When you measure the rolling torque, make sure that the rolling torque does not jump or increase over 1.35 N·m (12 lb in). If the rolling torque jumps over 1.35 N·m (12 lb in), return to Step 9 and use a smaller value for the rolling torque.
- Tighten the four locking screws of locknut (4) to 30 ± 7 N·m (22 ± 5 lb ft). Tighten the locking screws at least two times in order to ensure that the torque has been maintained on all four locking screws. Measure the rolling torque in order to ensure that the rolling torque has been maintained.
Note: The torque on the four locking screws is critical for the holding capacity of the locknut (4) .
Note: An increase in preload torque of 2.5 N·m (22 lb in) can occur after tightening the 4 locking screws on the adjusting nut for the pinion bearings. Max preload torque is 4 N·m (35.4 lb in).