PLATE AS 3316136 - Caterpillar

Problem
The H55D s hydraulic hammer experiences interference with certain custom thumbs when the hammer is also mounted on a quick coupler. The serial number range for the custom thumbs is 7JW4469-7929.Solution
Modify the thumb's frame by removing 8 mm (0.32 inch) of material from the outer radius. Refer to illustration 3. Remove the grease zerks and replace the grease zerks with 5M-6214 Pipe Plugs. Replace the stick's pin with a 300-3998 pin .Note: The 300-3998 pin must be ordered from Caterpillar Work Tools. 800-752-2858The affected thumbs can be identified by the thumb's profile. If the thumb has the profile that is shown in illustration 1, then a modification will be required. Illustration 2 shows the profile of a currently produced thumb that does not require a modification. Refer to table 1 for the part numbers of the affected thumbs.
Table 1
Affected Thumbs (1)
Serial Number S/N:7JW4469-7929    
288-4416     281-6681    
291-0832     204-4946    
289-3089     291-0832    
265-5850     289-2163    
( 1 ) Caterpillar Work Tools Custom Product. 800-752-2858
Illustration 1 g01333769
Profile of old design
Illustration 2 g01333770
Profile of new design
Illustration 3 g01333771
The arrow indicates the material that may be removed.