385B Excavator Adjustable Gage Undercarriage Frame Caterpillar

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Before extending or retracting the track frames, be sure to keep all other people away from the machine. Always use two or more people to do this work. Perform machine movements only after getting signals from a signal man. The automatic engine speed control (AEC) switch must be in the OFF position and the travel speed switch must be in the LOW position. Never make a sudden movement of the front equipment. When operating the front equipment, slowly activate the controls with extra care.

Illustration 1	g00285692

This machine has adjustable track frames that are held in place with bolts. The overall width of the machine with the track frame that is fully extended is 4000 mm (13 ft 1 inch). Completely widen the track frames when the machine is being operated. The overall width of the machine with the track frame that is fully retracted is 3500 mm (11 ft 6 inch).

Note: These specifications are for a machine with 750 mm (2 ft 6 inch) track shoes.

Retracting

Park the machine on a hard, level surface.

Retract the track frames one at a time.

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Illustration 2	g00581851

1. Position the machine with the front at a right angle to the track frame that is being retracted, as shown.

2. Stop the engine.
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   Illustration 3	g00810946

3. Remove the cover for the travel motor.
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   Illustration 4	g00811000
   (2) Carbody (3) Track frame (4) Bolts (5) Spacers

4. Remove bolts (4) and spacers (5). The bolts hold track frame (3) to carbody (2).

   Note: When you move track frame (3) in order to retract the overall width, do not loosen bolts (6) that are for the guide.

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   Illustration 5	g00286929

5. Start the engine. Apply downward pressure with the boom in order to raise the track approximately 50 cm (20 inch) above ground level.

6. Slowly run the raised track at a low idle. This will cause the raised track to slide toward the center of the machine. The full sliding distance should be 250 mm (10 inch).

7. After the raised track frame has been correctly retracted, lower the track frame to the ground.
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   Illustration 6	g00811008
   (2) Carbody (3) Track frame (4) Bolts (5) Spacers

8. Align the bolt holes of carbody (2) and track frame (3). Install bolts (4) and spacers (6). If necessary, slowly operate the machine back and forth until the bolt holes are aligned. Tighten the bolts to a torque of 2700 ± 300 N·m (2000 ± 220 lb ft).

   Note: To protect the bolt holes that are in the track frame from debris and mud, insert corks into eight bolt holes (A).

9. Repeat Steps 1 through 8 for the other track frame.

   Note: Store the bolts (4) and spacers (6) that were removed in this procedure in the tool box.

Extending

Park the machine on a hard, level surface.

Extend the track frames one at a time.

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Illustration 7	g00811008
(2) Carbody (3) Track frame (4) Bolts (5) Spacers

1. Remove the corks that are in bolt holes (A).

2. Remove bolts (4) and spacers (5). The bolts hold track frame (3) to carbody (2).

   Note: When you move track frame (3) in order to extend the overall width, do not loosen bolts (7) that are for the guide.

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   Illustration 8	g00286687

3. Position the boom over the opposite track frame with the stick at an approximate 80 degree angle to the ground. Place the bucket teeth into the ground, as shown. This machine position provides the best stability for extending the track frames.

4. Apply a downward pressure with the boom in order to slightly raise the track.
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   Illustration 9	g00286117

5. Use the STICK IN position to extend the track frame by moving the carbody away from the track.

6. After the track frame has been correctly extended, lower the raised track frame to the ground.
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   Illustration 10	g00811022
   (2) Carbody (3) Track frame (4) Bolts (5) Spacers

7. Align the bolt holes of carbody (2) and track frame (3). Install bolts (4) and spacers (5). If necessary, slowly operate the machine back and forth until the bolt holes are aligned. Tighten the bolts to a torque of 2700 ± 300 N·m (2000 ± 220 lb ft).

8. Repeat Steps 1 through 7 for the other track frame.