Usage:
3304 And 3306 Generator Set Engines;
D4E, D5B, And D6D Tractors;
561D Pipelayers;
12G, 14G, 120G, 130G, And 140G Motor Graders
- SUPPLEMENT: 07/12/82
SERVICE MAGAZINE, OCTOBER 12, 1981, PAGE 5. In the article, "Engine Slobbering; New Piston And Rings Used," the 3306 Engine arrangement number 1W1521 shown in Chart C is not correct. The correct arrangement number is 1W1531.
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- SUPPLEMENT: 12/21/81
SERVICE MAGAZINE, OCTOBER 12, 1981, PAGE 5. In the article, "Engine Slobbering; New Piston And Rings Used", the part number of the oil ring for the 9N5251 Piston Group in Chart A is not correct. The correct part is 9S7788 Ring (Oil). A note of this can be made in the last footnote (***) under Chart A.
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Description of Change: New pistons and rings are used in the piston and rod group for the above engines. The new rings give better control of engine slobbering if the engines are used in no load or low load applications. Engine slobbering can also be caused by worn or damaged turbocharger seals or valve guides.
Formerly, pistons and rings with a Keystone design were used. The new pistons and rings have a rectangular design and will decrease the possibility of engine slobbering.
Adaptable To: The new parts are a direct replacement for the former parts as shown in Chart A. The new groups are in effect with the serial numbers shown in Chart B and are adaptable to the machines or generator sets with the serial numbers shown in Chart C.
If engine slobbering is a problem on your machine, use the procedure which follows to correct the problem.
1. Check the turbocharger seals for wear or damage. Make replacements if necessary.
2. Check the valve guide clearance. See the Specification Section of the Service Manual for the correct specifications.
3. Install a 6N7174 Shield on each rotocoil assembly in the cylinder head.
4. If engine slobbering is still a problem, make a replacement of the former piston groups with the new piston groups.
