Grapple Damper Adjustment-If Equipped

The grapple damper limits the motion of the grapple head when travelling empty and prevents damage to the structural components, especially the yoke, crosshead, and pins.

Adjust the damper if the head swings to extreme heights or hits the stops. Adjust the damper by adding or subtracting the number of shim washers in the damper assembly.

1. Slightly loosen adjusting plugs (A) (every other plug or all six plugs) evenly to remove spring tension and to keep housing from rotating.

2. Remove three plugs (A).

3. Remove one shim washer (B) from each of the three plugs (A) to tighten grapple damper or add one shim washer to each plug to loosen.

4. Apply 3-5% moly grease to adjusting plug thread and the inside of plugs. Tighten plugs evenly until plugs contact shim washers.

5. Repeat steps 1-4 for other three plugs. Be sure that all plugs have an equal number of shims.

TEST CONDITIONS:

NOTE: The grapple head should be 10-15° from vertical under the following test conditions.

a. Close tongs, raise the grapple arch or boom to full height.

b. Lower the arch or boom slowly and bring to a smooth stop when the tongs are approximately 300 mm (12 in.) above the ground.

c. When properly adjusted, the grapple head will be 10-15° from vertical. Measure with a magnetic base inclinometer (C)


A-Plug (6 used)
B-Shim Washer (up to 24 used)
C-Magnetic Base Inclinometer

T8412AQ
T8412AR

CED,OUO1079,186 -19-14APR00-1/2

IMPORTANT: The snap ring gap is positioned at vertical top to maintain the grease level in the damper housing. During tightening of plugs it is important to retain this position by holding the damper housing with a pry bar.

Do not add any washers to the inside of the adjusting plugs in an attempt to tighten the damper assembly. This will cause the springs to become a solid member. Damage to the outer damper housing will result. If additional dampening is required after all shim washers are removed it is necessary to replace the disks inside the damper assembly. See your authorized dealer.

6. If additional tightness is required, remove shim washers from plugs with greatest number of shim washers. If additional looseness is required add shim washers to plugs with the least number of shim washers. Repeat steps 1-4 until desired tightness is achieved.

7. To hold damper housing in place use a pry bar between plugs. Tighten plugs to specification.

Specification

Grapple Damper Adjusting Plugs -Torque 184 N·m (250 lb-ft)

CED,OUO1079,186 -19-14APR00-2/2