TUBE 0870370 - Caterpillar

The pin alignment indicator (5) is a visual indicator for the operator. The pin alignment indicator (5) helps the operator know when the link assembly (3) is in the correct position to insert the adjusting pin. The bucket is the actuator for moving the thumb into position.
Illustration 9 g02783985
The thumb has two notches for different desired thumb angles. One notch is the 90 degree position and the other notch is the 105 degree position. As the bucket moves, the pin alignment indicator (5) slides along the guide plate (4).
Illustration 10 g02783986
Curl the bucket inward or open the bucket until the pin alignment indicator (5) is fully seated in the desired notch. Slowly move the bucket in and out, watching the top surface of the indicator block and the top surface of the guide plate. When the top surfaces are flush, the holes are aligned sufficiently and ready for the adjustment pin to be inserted. Note: Slight misalignment of the holes is required by design. Slight misalignment causes the indicator block to lift off the saddle on the guide plate when the adjustment pin is inserted. This ensures that the block is not loaded when the thumb is in use. Extreme loads are prevented from going through the block.
Illustration 11 g02789152
Ensure that the bores and the adjustment pin (2) are clean. Lightly coat the bores and the pin with grease to help reduce insertion force. Insert the adjustment pin (2). Some machines may require the use of a hammer in order to insert the pin.
Illustration 12 g02789154
Insert the cotter key (1) into the pin. Spread the ends of the cotter key to secure the pin. Unpinning the Thumb to Change Positions
Position the host machine on a surface that is level and solid.
Illustration 13 g02788387
Curl the bucket toward the thumb. Retract the stick inward toward the boom. Lower the boom.
Illustration 14 g02788394
Extend the bucket cylinder and curl the bucket until the bucket comes in contact with the thumb.
Curl the bucket back and forth until the thumb is slightly raised. If the thumb is raised too far or not far enough, the alignment pin will be under a load. Raising the thumb the correct amount will unload the pin joints and make the pin removal easier.
Illustration 15 g02788396
Remove the cotter key from the pin. Remove the pin. Some machines may require the use of a hammer in order to remove the pin.
If changing positions of the thumb, refer to , "Pin Alignment Indicator to Position Thumb in Working Position" for additional information. Folding the Thumb Up and Locking the Thumb in the Stored Position
Remove the adjustment pin from the thumb. Refer to , "Unpinning the Thumb to Change Positions".
Illustration 16 g02788404
Slowly retract the stick inward toward the boom. Slowly lower the boom. Maintain a minimum distance (A) of a 150 mm (6 inch) between the end of the thumb and the bottom of the boom. Note: No personnel should be within the working range of the host machine and the work tool. Once the thumb starts to drop, the