2004/11/01 Caterpillar

Engine:

G3512 (S/N: 7NJ1-UP)

G3516 (S/N: 3RC1-UP)

G3520B (S/N: GET1-UP)

3508 (S/N: 1FZ1-UP; 95Y1-UP; 23Z1-UP; 68Z1-UP; 70Z1-UP; CTF1-UP; 1JZ1-UP)

3508B (S/N: CBB1-UP; S2B1-UP; 3DM1-UP; 4GM1-UP; 6PN1-UP; 2HW1-UP; 3DW1-UP; BPX1-UP; CTC1-UP)

3512 (S/N: 1GZ1-UP; 49Y1-UP; 24Z1-UP; 65Z1-UP; 67Z1-UP; CTE1-UP; 1KZ1-UP)

3512B (S/N: CTB1-UP; BRC1-UP; S2K1-UP; 8EM1-UP; 8RM1-UP; 6WN1-UP; 1PW1-UP; 4AW1-UP; 5AW1-UP; CTH1-UP)

3516 (S/N: 1LZ1-UP; 5SJ1-UP; 27Z1-UP; 71Z1-UP; 73Z1-UP; CTD1-UP; 25Z1-UP)

3516B (S/N: CTA1-UP; CTG1-UP; CTJ1-UP; 6HN1-UP; 7RN1-UP; 9AN1-UP; 1NW1-UP; 2FW1-UP; 2JW1-UP; 1HZ1-UP)

Generator Set:

3508 (S/N: CNF1-UP)

3508B (S/N: CNB1-UP)

3512 (S/N: CMJ1-UP)

3516 (S/N: CMD1-UP)

3516B (S/N: CPA1-UP; FDN1-UP; BPJ1-UP)

G3520B (S/N: CWD1-UP)

Engine News SEBD9339, November 2004, "Improved Fan Drives". Disregard this article. Refer to the following article.

Description of Change: Fan drives have been improved in order to help eliminate vibration and bearing wear for the 3500 Engines and Generator Sets that are listed above. The improved fan drives have the same design that is used in Machine Engines. A pair of tapered roller bearings are used. The spanner nut and the tabbed washer have been eliminated. There is no longer an adjustment procedure for the spanner nut. The bearings are retained by clamping the bearing inner races between a shoulder on the drive shaft hub and a thick washer that is bolted to the outer end of the shaft. Refer to Illustration 1. A precisely manufactured spacer sleeve is installed on the shaft in order to fill the gap between the two bearings. Refer to Illustration 2.

A change to an assembly process has been made in order to ensure proper lubrication of the drive pulley.

Adaptable To: The changes to the fan drive are adaptable to all of the 3500 Engines that are listed above. Table 1 lists the part numbers that are affected by the change.

Table 1

Part Number

7C-1664 Fan Drive Gp

7C-1665 Fan Drive Gp

7W-3952 Fan Drive Gp

7W-3953 Fan Drive Gp

230-2578 Fan Drive Gp

Table 2 lists the new parts and the former parts within the fan drive groups.

Table 2

New Parts and Former Parts
New Part		Former Part
Part Number	Description	Part Number	Description
6Y-7651	Bearing Cone	4B-7255	Bearing Cone
7E-4202	Hard Washer	065-7892	Washer
7K-4370	Bolt
209-5296	Spacer	2H-3778	Locknut
217-6916	Washer	065-7893	Bearing Lockwasher
251-7648	Fan Bracket Assembly	127-8122	Fan Bracket Assembly
251-7645	Shaft	7W-6488	Shaft

Table 3 lists the effectivity for the new fan drive groups.

Illustration 1	g01046601
(1) Bolt (2) Washer

Illustration 2	g01054072
(3) Shaft (4) Sleeve

Illustration 3	g01046602
(5) Hub (6) Bearing

Table 3

Serial Number Effectivity
(S/N: 95Y01238-UP)	(S/N: 3DM00494-UP)	(S/N: 2FW00346-UP)	(S/N: CTE00375-UP)
(S/N: 49Y01063-UP)	(S/N: 8EM00534-UP)	(S/N: 2HW00286-UP)	(S/N: CWD00232-UP)
(S/N: 27Z00875-UP)	(S/N: 9AN00378-UP)	(S/N: 4AW00918-UP)	(S/N: CTF00266-UP)
(S/N: 23Z07954-UP)	(S/N: 6PN00895-UP)	(S/N: 1NW00145-UP)	(S/N: CTC00258-UP)
(S/N: 24Z10169-UP)	(S/N: 8RM00762-UP)	(S/N: BPX00103-UP)	(S/N: CTH00317-UP)
(S/N: 25Z07106-UP)	(S/N: 7RN01960-UP)	(S/N: BRC00160-UP)	(S/N: CTJ00200-UP)
(S/N: 68Z01271-UP)	(S/N: 4GM00743-UP)	(S/N: CBB00247-UP)	(S/N: 1HZ02913-UP)
(S/N: 70Z01080-UP)	(S/N: 6WN00803-UP)	(S/N: GET00115-UP)	(S/N: CTG00326-UP)
(S/N: 65Z01159-UP)	(S/N: 6HN01720-UP)	(S/N: S2B00119-UP)	(S/N: 1FZ02498-UP)
(S/N: 67Z02107-UP)	(S/N: 2JW00415-UP)	(S/N: S2K00108-UP)	(S/N: 1GZ02123-UP)
(S/N: 71Z00406-UP)	(S/N: 5AW00138-UP)	(S/N: CTB00200-UP)	(S/N: 1KZ01979-UP)
(S/N: 73Z00975-UP)	(S/N: 3DW00186-UP)	(S/N: CTA00155-UP)	(S/N: 1LZ00775-UP)
(S/N: 7NJ01119-UP)	(S/N: 1PW00442-UP)	(S/N: CTD00217-UP)	(S/N: 1JZ00783-UP)
(S/N: 3RC01222-UP)	(S/N: 5SJ00514-UP)	(S/N: BPJ00347-UP)	(S/N: CMD00140-UP)
(S/N: CMJ00117-UP)	(S/N: CNB00200-UP)	(S/N: CNF00203-UP)	(S/N: FDN00107-UP)