- Mini Hydraulic Excavator
- 305.5E (S/N: MX51-UP)
- 306E (S/N: FHL1-UP)
Introduction
This Special Instruction provides the instruction for inspecting and reworking the bolts for the swing gear and bearing for certain 305.5E and 306E Mini Hydraulic Excavators.
| Effectivity and Adaptability of the Inspection and Rework Procedure | ||
|---|---|---|
| Sales Model | Effectivity | Adaptability |
| 305.5E | S/N:MX51-102,478-UP | S/N:MX5103-477 |
| 306E | S/N:FHL1-581,878-UP | S/N:FHL582-877 |
Safety
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Do not attempt to assemble this machine until you read and you understand the assembly instructions. Improper assembly procedures could result in injury or death. |
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Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system. Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on. |
| NOTICE |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products. Dispose of all fluids according to local regulations and mandates. |
Note: Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.
References
Reference: 305.5E Disassembly and Assembly, UENR3346
Reference: 306E Disassembly and Assembly, KENR9860
Required Parts
| Required Parts | ||
|---|---|---|
| Part Number | Part Name | Qty |
| Swing Gear and Bearing Gp(1) | 1 | |
| Swing Gear and Bearing Gp Bolt(2) | 1 | |
| Plate Grease | 1 | |
| Bolt | 38 | |
| - | Molykote G-Rapid Plus Paste | |
| (1) | Sales Model 306E |
| (2) | Sales Model 305.5E |
Swing Bearing Bolt Torque Inspection
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Personal injury or death can result from unintended rotation of the machine's upper structure once the swing drive motor is removed. After the swing drive motor is removed, the machine's upper structure is no longer mechanically held in place and is free to rotate. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the machine is positioned on level ground and the area around the machine is clear of personnel and obstructions. |
- Move the machine to level ground.
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Illustration 1 g03875664 - Position the upper structure parallel to the tracks as shown in Illustration 1.
- Raise the implements approximately
152 mm (6 inch) off the ground and mechanically block the cylinders as necessary. - Remove the swing motor assembly from the machine. Refer to Disassembly and Assembly, UENR3346 or KENR9860 , "Swing Motor - Remove and Install".
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Illustration 2 g06028231 - Inspect swing motor assembly pinion teeth for damage. If damaged, repair swing motor assembly accordingly.
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Illustration 3 g06028137 - Through the access in the upper frame, clean up the swing bearing inner bolt area. Refer to Illustration 3 for the swing bearing inner bolt area.
- Check residual torque of the bolt by applying
200 N·m (147.5 lb ft) of torque in the clockwise direction.- If the bolt moves during the residual torque inspection process, proceed with the following steps:
- Remove the bolt.
- Clean the abutment surfaces, ensuring not to get grease or oil into the threads of the ring.
- Using a new 447-1708 Bolt, apply Molykote G-Rapid Plus Paste to the threads of the bolt, and install onto inner bearing race. Tighten the bolt to a torque of
240 ± 40 N·m (177 ± 30 lb ft) .
- If the bolt does not move, proceed with the following step:
- Retorque the bolt at
240 ± 40 N·m (177 ± 30 lb ft) .
- Retorque the bolt at
Note: DO NOT over torque the bolt.
- If the bolt moves during the residual torque inspection process, proceed with the following steps:
- Repeat Step 7 for the remainder of the inner bearing race bolts. Use a suitable device to rotate the upper frame.
Note: Place a paint mark on each subsequent bolt after applying the final torque to ensure successful completion of all bolts. Confirm that there are 18 inner race bolts installed.
- Inspect the swing bearing inner race bolt holes. If bolt holes are elongated, replace with a new swing bearing assembly.
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Illustration 4 g06028140 - Repeat Step 7 to Step 9 for the swing bearing outer race bolt. Refer to Illustration 4.
Swing Bearing Assembly Replacement with Further Inspection and Rework
- Remove the undercarriage frame from the machine. Refer to Disassembly and Assembly, UENR3346 or , KENR9860 , "Upper Frame and Undercarriage Frame - Separate".
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Illustration 5 g06027822 Grease pan - Inspect the grease pan for damage. Replace the grease pan if the bolt holes are deformed. Refer to Table2 for part number.
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Illustration 6 g06028188 Swing bearing outer race mounting ring Show/hide table
Illustration 7 g06028210 Swing bearing inner race mounting ring - Replace swing bearing assembly. Refer to illustration 6 and 7.
Note: Refer to Disassembly and Assembly, UENR3346 or , KENR9860 , "Swing Gear and Bearing - Remove and Install".
- Replace all swing bearing outer and inner race bolts with new 447-1708 Bolts. Refer to Step 8.
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Illustration 8 g06028202 Upper carriage underside - Remove and inspect the upper carriage underside. Repair upper carriage underside if damaged.
- Broken bolts in the undercarriage ring can be extracted and weld repaired if the damage to the surface is minimal.
- Clean all surfaces prior to reassembly.
- Assemble the swing bearing to the undercarriage frame using new 447-1708 Bolts.
- Apply Molykote G-Rapid Plus to the threads of four new 447-1708 Bolts.
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Illustration 9 g06027824 Bolt hole locations - torque sequence - Immediately install bolts into the corresponding holes 1 though 4, as shown in Illustration 9.
- Tighten the bolts to a torque of
240 ± 40 N·m (177 ± 30 lb ft) . - Apply Molykote G-Rapid Plus to the threads of a new 447-1708 Bolt.
- Place the bolt into corresponding hole number 5, as shown in Illustration 9.
- Tighten the bolt to a torque of
240 ± 40 N·m (177 ± 30 lb ft) . - Repeat Steps 8.d through 8.f in a clockwise or counterclockwise direction for bolts 6 through 18.
- Apply Molykote G-Rapid Plus to the threads of four new 447-1708 Bolts.
- Once the swing bearing has been assembled to the undercarriage frame, the upper and lower frames can be reassembled. Clean the surface areas thoroughly to ensure that no grease or oil goes into the threads of the ring.
- Apply Molykote G-Rapid Plus to the threads of the new 447-1708 Bolt.
- Install the new 447-1708 Bolt to the outer bearing race.
- Mark each torqued bolt to ensure that none of the bolts are missed.
Note: Torquing the bolts for the outer bearing race using a cross pattern method is not necessary.
- Repeat Steps 10 through 12 for the remaining bolts.
- Reassemble the machine. Refer to Disassembly and Assembly Manual, UENR3289 or , KENR9860.
