PRODUCT SUPPORT PROGRAM FOR REWORKING CYLINDER HEAD VALVE ROTATOR INTERFERENCE ON CERTAIN G3516 AND G3520 ENGINES

Usage:

SEBE9307-02

August 16, 2005
(Revised May 2006)
U-275
A-198
D-212
O-227

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*before or* *after failure*	PRODUCT SUPPORT PROGRAM FOR REWORKING CYLINDER HEAD VALVE ROTATOR INTERFERENCE ON CERTAIN G3516 AND G3520 ENGINES
1120		PS41904

NOTE: This Program can be administered either before or after failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS41904" as the Part number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.

NOTE: 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.

NOTE: This Revised Service Letter replaces the August 16, 2005 (Revised November 2005) Service Letter. Changes have been made to the Parts Needed section.

TERMINATION DATE

August 31, 2007

PROBLEM

The cylinder head rocker arm base needs to be inspected on certain G3520 engines. The cylinder head valve rotator could interfere with the underneath side of the rocker arm base. During the normal valve recession process the rotator could recess high enough to make contact with the base, damaging both and leading to possible valve failure. The engines need to be inspected and adjusted if necessary.

AFFECTED PRODUCT

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Model	Identification Number
G3516	TJB101-109 TJC817-819
G3516B	GAS111-120
G3516C	GZZ114-134
G3516E	SLY106-109
G3520C	B9P200-214 CWW200-295, 299-300 CWY200-221 HAT200-204, 206-211 GDB0001-37 GHC150-152 HEB103-104 HEA101-102 JBX100-101 JBZ101 MAD200-201
G3520E	GHR150-152

PARTS NEEDED

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Qty	Part Number	Description
*	2037859	O-Ring Seal

*NOTE: Order one seal per cylinder.

ACTION REQUIRED

See the attached Rework Procedure.


SERVICE CLAIM ALLOWANCES

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Product smu/age whichever comes first	Caterpillar		Dealer Suggested		Customer Suggested
Product smu/age whichever comes first	Parts	Labor Hrs	Parts	Labor Hrs	Parts	Labor Hrs
0-20,000 hrs	N/A	100%	0	0	0	0
NOTE: Allow an additional $500.00 for machining cost. Labor should not exceed 45 minutes per cylinder.

PARTS DISPOSITION

Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.

Attach. (1-Rework Procedure)

Rework Procedure

Rotate engine and inspect when valves are fully closed. To determine whether the valves are fully closed refer to Testing and Adjusting (RENR5978-06), "Finding the Top Dead Center Position for No. 1 Piston" and Testing and Adjusting (RENR5978-06), "Crankshaft Position for the Valve Lash Setting".
Using a 4.0 mm (0.157 inch) thickness gage place between the top of the rotator and the underneath side of the rocker arm base. (Refer to attachment #1). If the thickness passes thru the space the clearance is OK. Measure all four rotator positions for clearance.

If OK, you do not need to adjust this position on the rocker arm base.

If the thickness gage will not go thru the space between the rotator and the underneath side of the base, the rocker arm base will need to be machined.
To machine the clearance into the rocker arm base, the base needs to be removed from the cylinder head- (reference Disassembly and Assembly manual RENR5980-07).
Machine the underneath side of the rocker arm base to the dimension from the clearance cut to the top of the base should be 21.3mm +/- 1.0mm (0.838 +/- .039 inches) Reference Attachment #2 and #3.
Make sure the machined area is smooth and no rough edges are present; avoid potential stress risers that may initiate cracks.
Replace the base onto the engine (reference Disassembly and Assembly manual RENR5980-07)