SHAFT AS-INPUT 3304576 - Caterpillar

Caterpillar: Confidential Yellow
PSP FOR INTAKE VALVE FAILURES IN JAPANESE BUILT 950B, 963 AND 973 LOADERS; D7G TRACTORS - MAILED COSA AND CFEL ONLY
  The information supplied in this service letter may not be valid after the termination date of this program.   Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
PRODUCT SUPPORT PROGRAM FOR INTAKE VALVE FAILURES IN JAPANESE BUILT 950B, 963 AND 973 LOADERS; D7G TRACTORS, 1105, PS0267 E-51 O-48 This Program can only be administered after a failure occurs. The decision whether to apply the Program is made by the dealer. When reporting the repair use "PS0267" as Part Number and "7755" as Group Number. Termination Date
September 30, 1986.
Problem
There have been intake valve failures (Chordal) in the above machines. The valves can crack in the valve head and may eventually result in a part of the valve head separating from the valve. This has only been a problem on Japanese built engines using the 7N572X Valve (Intake). The cause of the failures is the welding process that was used to attach the facing material to the head. A new welding process is now used in production.
Affected Product
Model Product Identification Number 950B Loaders 65R1088-2261 963 Loaders 29S1030-1112 48Z164-183 973 Loaders 90L502-650 91L157-163 D7G Tractor 64V1107-1153 65V4614-5123 44W441-505 45W407-428 7MB1-913
Parts Needed
950B 4 - 2W2620 Valve 1 - 6V5407 Gasket Kit 963 4 - 2W2620 Valve 1 - 6V4776 Gasket Kit 973 6 - 2W2620 Valve 1 - 6V2531 Gasket Kit D7G 6 - 2W2620 Valve 1 - 6V4784 Gasket Kit
Action Required
If there has been an intake valve failure, remove the 7N572X Valves (Intake). Install the new 2W2620 Valves (Intake) and the