CAMSHAFT AS 4522503 - Caterpillar

3ZJ1
This change provides a new 4P7693 Carrier to replace the former 4P1636 Carrier to solve a manufacturing problem. This change will service back to first production of the new style timing advance (4MG3600). The part number of the new drive groups released are the 4P1923, 9Y5395, 4P1925, 4P1401, 4P1403, 4P1408, 4P1409, and 4P1922.
3ZJ911
This change provides a new thicker leg flyweight, race, carrier assembly, and spool. This change will help reduce the chance of fly weights binding or breaking. The carrier no longer has the acceleration noise control orifice. The components involved with this change are the 4P7693 Carrier, 4P7692 Weight, 4P7690 Race, 4P7691 Spool, and 4P2641 Carrier Assembly. Those components are required to service back to first production of 3ZJ1.
3ZJ-(See Chart)
This change provides new "heat set" springs that do not change load characteristics over time when exposed to engine heat. These new springs will help better maintain factory timing advance settings. A list of Drive Groups and their corresponding new springs follow:
Electronic
8TC1
This change provides the 2W4544 Drive Group for the 8TC engine introduction.
8TC----(Unknown)
This change provides the new 7W0993 Drive Gear with improved material quality. This change will service the former drive gear back to 8TC1.
8TC----(Unknown)
This change provides the new 7W3218 Ring (Quadseal) with improved material quality. This change will service the former ring back to 8TC1.
8TC----(Unknown)
This change provides the new 3P3547 Clip (used to retain the brushless torque motor sleeve assembly on the spool). This change will service the former clip back to 8TC1. (Also the see 4CK15345 improvement.)
8TC8730
This change provides the new stronger 7E5564 Spool. This change will service the former spool back to 8TC1. (Also see the 8TC13234 and 5YG1 improvements.)
8TC12973
This change provides a the new 7E9060 Carrier Assembly which eliminates body-carrier slip. The preferred service method is to service the 2W7986 Body Assembly, 8F1145 Ring, 1W4329 Carrier, and 4W2754 Seal with the new 7E9060 Carrier Assembly.
8TC13234 And 5YG1
This change provides the new 4P2648 Drive Group for use on the 5YG engine. This release also provides the new 4P3500 Sleeve Assembly and 4P3384 Spool with improved material properties for the 2W4544 (8TC1) and 4P2648 (5YG1) Drive Groups. The new sleeve assembly and spool will service back to 8TC1. The 4P2648 Drive Group is like the previously built 2W4544 Drive Group except for the new 4P3500 Sleeve Assembly and 4P3384 Spool.
8TC13823
This change to the 2W4544 Drive Group provides eight mounting bolts instead of the former four for increased clamping and reduced slippage. The carrier assembly is changed to accommodate a larger 52 tooth spline. These changes are not adaptable to earlier 8TC engines or any 5YG engines. This change occurred at the end of the 5YG serial number prefix. The components involved with change include the 4P2921 Ring, 4P2642 Carrier Assembly, 9X7715 Seal, 4P2922 Plate, 4P2923 Ring, and eight 0T0065 Bolts.
2EK1823 And 4CK993
This change provides the new longer 6J2819 Bolt for improved torque retention. The new bolt will service back to 8TC1.
4CK4699
This change provides the new 1011944 Carrier Assembly. This new carrier assembly has a threaded plug