An Improved Bolt Tightening Procedure for the Critical Joints Is Now Used on All Excavators {4050, 4164, 5459, 7063} Caterpillar

Excavator

All

Description Of Change: An improved bolt tightening procedure for the critical joints is now used on the machines listed above. This torque and turn bolt tightening procedure is recommended at the field service. This procedure is more robust and reliable and will ensure better retention of the bolts and improves the service life for the critical joints.

Adaptable To: The following changes are adaptable to the products within the listed serial numbers, and are effective with all products after the listed serial numbers.

Tightening Procedure

Before installing the bolts, ensure that the two bolted joint surfaces are clean. Confirm that the surfaces have no excessive fretting and are free from rust. The threaded mounting bolt holes should be clean of debris. Use proper tooling to clean threads using a thread chaser or thread cleaner.

Note: Do not reuse the bolts once tightened by this torque and turn process.

Note: Do not use a Tap to clean the threads.

Note: Make sure that the old compound is removed from the tap hole.

Note: New bolts ordered through the CAT parts ordering system are service replaced by bolts without compound. Make sure that the appropriate compound is applied before assembly.

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Illustration 1	g06209263
(A) Final drive bolts (B) Sprocket bolts (C) Swing drive bolts (D) Swing bearing inner & outer bolts

1. Before assembly, apply the appropriate compound to the bolt threads. Refer to "Torque and Turn Specifications" for the correct compound material.

2. Install the bolts and pretorque. Refer to "Torque and Turn Specifications" for correct torque value.

   Step 3to Step 8 shows the procedure to reach correct turning angle.

3. Put a proper size of socket on the protractor.
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   Illustration 2	g06224888

4. Draw a mark (E) at zero degree and another mark (F) on the target angle at the outside of the socket. Refer to Illustration 2. Make sure that the line is visible from top.

5. Place the socket on the bolt head.
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   Illustration 3	g06224890

6. Draw a mark (G) on the machine surface. Refer to Illustration 3.

7. Tighten the bolt by the target angle.

8. Remove the socket.

9. Repeat Step 3 to Step 8 for other bolts.

Alternate Method

To achieve the correct turning angle, 6V-6080 Torque Multiplier Gp is recommended if applicable.

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Illustration 4	g06224944
(H) 6V-6080 Torque Multiplier Gp

1. Set a proper size of socket on torque multiplier (H). If needed, put an extension bar on torque multiplier.

2. Place a socket on the bolt head and bring the reaction arm against the frame. Make sure that the reaction arm is well anchored.

3. Bring the scaled ring of the torque multiplier in front of the zero degree position.
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   Illustration 5	g06224945

4. Draw a mark (J) on the surface of the machine.
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   Illustration 6	g06224946

5. Rotate torque multiplier (H) until the scaled ring reaches the target angle (K).

6. Remove torque multiplier (H) and socket.

7. Repeat Step 2 to Step 6 for the other bolts.

Torque and Turn Specifications

Final Drive

Swing Drive

Swing Bearing

Sprocket