VALVE-CHECK 9T8844 - Caterpillar

3412 (9XF171-Up),
3412C (38S19666-Up, 2SZ239-Up, 8AR805-Up),
3412E (4CR1045-Up) Industrial Engines;
3412 (7DB1477-Up),
3412C (6ZM201-Up) Industrial Gas Engines;
3412 (2WJ2165-Up),
3412C (3FZ788-Up, 1EZ472-Up, 81Z23664-Up) Generator Set Engines;
3412C (9RR417-Up) Gas Generator Set Engines;
3412 (7BL189-Up),
3412C (3JK1534-Up, 60M7586-Up, 9BR590-Up),
3412E (9KS271-Up) Marine EnginesSUPPLEMENT: NOVEMBER 1999Engine News SEBD9276, Article 3, Page 5, September 1999; "Wider Crankshaft Gear Used".The last sentence of the first paragraph is incorrect. The sentence should read as follows: "The new gear also requires a new timing gear housing". The title of the table in this article is also incorrect. The title should read as follows: "Housing - Timing Gear Changes".
--------------- END SUPPLEMENT ---------------Description of Change: A new crankshaft spur gear is available for the above engines. The new spur gear is 23.50 mm (.925 in) wide and is 5.72 mm (.225 in) wider than the former spur gear. The new gear provides for a longer service life. The new gear also requires a new flywheel housing.Adaptable To: The new 151-2940 Crankshaft Gear replaces the former 114-0966 and 2W-3878 Crankshaft Gears. The new crankshaft gear requires a different timing gear housing to provide clearance with the wider gear. The following table gives the appropriate housing changes. The timing gear housing dimension from the gasket mounting face to the rear of the crankshaft seal mounting flange increased from 25.5 mm (1.004 in) to 29 mm (1.142 in). The crankshaft seal flange is the 10 mm (.40 in) wide flange that has a 206 mm (8.11 in) outside diameter that contains the front crankshaft seal.
The former 114-0966 Crankshaft Gear is still serviced for applications where the new or reworked timing gear housing change is not desirable.
The 0R-9751 Crankshaft Assembly (with the wider gear) is available as a remanufactured upgrade to new crankshaft assembly. 0R-2812, 0R-1207, 0R-1229 Crankshaft Assemblies (with the narrow gear) are also available as a remanufactured product.