MOUNT 6N8744 - Caterpillar

Engine C27 Engines C32 EnginesIntroduction
This Special Instruction provides information for the improved camshafts, rocker arms, and high-pressure oil pumps used on C27 and C32 Machine Engines.C27 / C32 engine are defined as below:1. C27 or C32 Engine with MEUI-A Injectors:a. Engines built between 2005-2012 with MEUI-A injectors and/or engines built for legacy machines.b. LRC (Lesser Regulated Country) engine: Current machines engine with emission rating equivalent to US EPA Tier 2 / 3 with MEUI-A Injectors.2. C27 or C32 engine with MEUI-C Injectors: Current machine engine that meets US EPA Tier 4 Final.Note: A factory engine build date will be required to understand appropriate changes for given engine. This date can be determined by entering engine serial number into Technical Marketing Information (TMI) web application.Improved Rocker Arms
The new rocker arms have a coated pin that provides less friction at the roller and pin contact area. This reduced friction decreases the stress between the roller and the camshaft lobe.The new rocker arms are direct replacement for former rocker arms. The new rocker arms are adaptable back to the first production on C27 and C32 Machine Engines.
Illustration 1 g03681080
(1) Valve rocker arm
(2) Injector rocker arm
(3) Coated roller pin
Table 1
New Reman Group Former Reman Group New Rocker Arm Former Rocker Arm
20R-3319 10R-3483 437-3880 278-1363
20R-3323 10R-6098 437-3879 322-9168
20R-3328 20R-1897 437-3870 384-1366 The change is effective at the factory with engine build date of 13 March 2014, and 04 March 2014for Tier IV-specific enginesThe change is effective on Reman engines and long blocks built on or after 14 May 2014.Note: Reman groups include adjusting screw and nut. The Reference New Assembly does not. Refer to Table 1 for a list of new and former Reman groups.The effective serial numbers for Reman engines and long blocks are listed in Table 2.
Table 2
Effective Serial Numbers
S/N:LET00605-UP
S/N:DGK00161-UP
S/N:KCM00577-UP
S/N:DGL00230-UP
Illustration 2 g03681160
Typical 384-1367 Valve Rocker Arm
Visual reference chart for base level part identification
(4) New oil path
Illustration 3 g03681163
Visual reference chart for base level part identification
The upper pictures directly below the part numbers show a cut away of the rocker arms, with or without, the oil paths.
The lower pictures show the complete rocker arms for the same part numbers above.
(5) Oil pathsFormer rocker arms included various improvements, most recently the addition of an oil hole for the cam roller outer surface, shown in Illustrations 2 and 3.Note: This new hole required increased oil pressure at the pump to provide the increased oil flow needed. Refer to "Higher Pressure Oil Pumps" for more information.Progression of Rocker Arms Groups
Refer to Table 3 for the progression of rocker arm part numbers.
Table 3
Progression of Rocker Arm Group C27/C32 ACERT Engine
MEUI (Same for Brake and Non Brake) Part Number Description Nitride Cut Threads P/N Non Nitrided Rolled Threads P/N Isotropic Finish Injector P/N Isotropic Finish Variable P/N Forged Exhaust Rocker Arm P/N Oil Hole Forged Rocker Arms P/N(1) DLC and Oil Hole Forged Rocker Arms P/N(1)
MEUI A / LRC (Same for Brake and Non Brake) Arm Gp - Valve Rocker 243-2468 280-8043 301-5349 320-2793 342-6643 392-0066 437-3876
Arm Gp - Unit