SHAFT-OUTPUT 6Y3148 - Caterpillar

ENGINES
3176B (3NL) INDUSTRIAL ENGINES;
3176B (9CK) TRUCK ENGINES;
3176C (2AW) INDUSTRIAL ENGINES;
C-10 (2PN, 8YS) TRUCK ENGINESProblem:
There have been some reports of oil leaks from the rear of these engines. The majority of these occurrences have been on engines with RPTO. Originally, the engine main bearing caps were manufactured with one machining pad in the lower-middle portion of the cap, and the RPTO/flywheel housing was machined with a corresponding notch. Later, to increase machining accuracy, the main bearing caps were manufactured with two machining pads, one on the lower-left and one on the lower-right portion of the cap. (See Illustration 1.) The RPTO/flywheel housing was not adapted to this change. At times, the rear main bearing cap may exceed the length of the block when it is assembled. When installed, the RPTO/flywheel housing does not seat properly against the block due to the machining pads on the rear main bearing cap. (See Illustration 2.) This causes a space between the block and housing, which causes an oil leak.Solution:
Remove any necessary equipment to access the RPTO/flywheel housing. Remove the RPTO/flywheel housing. Find the included Illustration 3 "Notch Template". Cut the "Notch Template" out and place it face up on the block side of the RPTO/flywheel housing using the center notch and bolt holes as guides. Trace the two new notches on to the RPTO/flywheel housing. Grind the two relief notches in the RPTO/flywheel housing to a depth of 3.5 mm or 1/8 inch. Reinstall the RPTO/flywheel housing using the recommended sealant and proper procedures for that engine. This topic is covered in the Power Connection; Live July 8, 1998; Video Tape; LEVN4438.Please share this information with your TEPS Dealers.
Illustration 1.Locations of the two machining pads on the crankshaft main bearing cap.
Illustration 2.Locations of possible interference between the rear main bearing cap and the RPTO/flywheel housing. Use the included "Notch Template" to mark these areas to grind relief notches.
Illustration 3."Notch Template"COPYRIGHT 1998 CATERPILLAR ALL RIGHTS RESERVED