2003/08/01 Caterpillar

Generator Set Engine:

3406C (S/N: 9ES1-UP; LRX1-UP)

Description of Change: A new oil pump is being used in order to increase the service life of the oil pump. The new oil pump assembly utilizes steel gears on the idler shaft and on the drive shaft. The steel gears have better wear characteristics than the gears that are currently used.

Adaptable To: This change is adaptable to the following serial numbers:

• 9ES1-5326, 5328-5338, 5340-5341, 5344, 5346, 5348-5357, 5361, 5363-5391, 5400, 5404, 5406-5407, 5411-5413, 5421-5425, 5429, 5433-5434, 5436-5455, 5457-5459, 5461, 5466, 5468-5470, 5472-5480, 5483-5484, 5487-5488, 5491-5515, 5528, 5530, 5548, 5557-5564, 5566

• LRX1-187, 193-195

This change is effective with the following serial numbers:

• 9ES5327, 5339, 5342-5343, 5345, 5347, 5358-5360, 5362, 5392-5399, 5401-5403, 5405, 5408-5410, 5414-5420, 5426-5428, 5430-5432, 5435, 5456, 5460, 5462-5465, 5467, 5471, 5481-5482, 5485-5486, 5489-5490, 5516-5527, 5529, 5531-5547, 5549-5556, 5565, 5567-UP

• LRX188-192, 196-UP

The 161-4111 Engine Oil Pump Gp is a direct replacement for 4N-0733 Engine Oil Pump Gp .

9Y-4633 Oil Pump Idler Shaft Assembly and 9Y-4632 Oil Pump Drive Shaft Assembly are cancelled. 9Y-4632 Oil Pump Drive Shaft Assembly is replaced by 1W-7238 Pump Drive Shaft Assembly. 9Y-4633 Oil Pump Idler Shaft Assembly is replaced by 1W-7239 Idler Shaft Assembly .

During a rebuild of 4N-0733 Engine Oil Pump Gp, use 1W-7239 Idler Shaft Assembly and 1W-7238 Pump Drive Shaft Assembly.

Table 1

Former Part Number	Cancelled	Current Part Number	Part Description
4N-0733	N	161-4111	Engine Oil Pump Gp
9Y-4633	Y	1W-7239	Idler Shaft Assembly
9Y-4632	Y	1W-7238	Pump Drive Shaft Assembly