2008/11/24 Caterpillar

Engine:

3116 (S/N: 8WL1-UP)

3176B (S/N: 9CK1-UP)

3406B (S/N: 4TB1-UP; 4JK1-UP)

3406E (S/N: 5EK1-UP; 1MM1-UP; 2WS1-UP; 5DS1-UP; 6TS1-UP; 1LW1-UP; 4AS1-UP)

3408E (S/N: 7PR1-UP)

3412 (S/N: 2WJ1-UP; 4BZ1-UP; 3JK1-UP; 60M1-UP; 38S1-UP; 81Z1-UP)

3412C (S/N: BAK1-UP; 8AR1-UP)

3412E (S/N: 4CR1-UP)

3508 (S/N: 96Y1-UP; 23Z1-UP)

3508B (S/N: CNB1-UP; 2BM1-UP; 6PN1-UP; 2HW1-UP)

3512 (S/N: 1LM1-UP; 24Z1-UP; 66Z1-UP; 67Z1-UP)

3512B (S/N: 2AF1-UP; 8EM1-UP; 8RM1-UP; 4TN1-UP; 1PW1-UP; 3ZW1-UP; 6GW1-UP)

3516 (S/N: CMD1-UP; 29Z1-UP; 73Z1-UP; 25Z1-UP)

3516B (S/N: BCK1-UP; FDN1-UP; 6HN1-UP; 7RN1-UP; 9AN1-UP; 2JW1-UP; 4BW1-UP; 8NW1-UP)

3612 (S/N: 9RC1-UP)

C-12 (S/N: 2KS1-UP)

C-15 (S/N: MBN1-UP; 6NZ1-UP; 9NZ1-UP)

C-16 (S/N: 7CZ1-UP)

G3406 (S/N: 4FD1-UP)

G3408 (S/N: 6NB1-UP)

3408E (S/N: 67U1-UP; 78Z1-UP)

G3412 (S/N: 7DB1-UP)

G3412C (S/N: 6ZM1-UP)

G3512 (S/N: 7NJ1-UP)

G3516 (S/N: 3RC1-UP; 4EK1-UP; CSZ1-UP)

G3516B (S/N: 7EZ1-UP)

3126 (S/N: 6RW1-UP)

Generator Set:

3406 (S/N: 4ZR1-UP)

3406B (S/N: 2WB1-UP)

3406C (S/N: 1LS1-UP; 9ES1-UP)

Industrial Engine:

3406B (S/N: 6TB1-UP)

3406C (S/N: 3ER1-UP)

3406E (S/N: 6BR1-UP)

3412E (S/N: BDT1-UP)

3456 (S/N: 3LW1-UP)

C-15 (S/N: BEM1-UP)

C-16 (S/N: BFM1-UP)

Marine Engine:

3406E (S/N: 9WR1-UP)

3408 (S/N: 99U1-UP)

3408C (S/N: 9ER1-UP)

3412E (S/N: 9KS1-UP; 9PW1-UP)

Truck Engines:

3126E (S/N: CKM1-UP)

3406B (S/N: 5KJ1-UP)

3406C (S/N: 8PN1-UP)

Power Module:

PM3516 (S/N: BPD1-UP)

Bearing discoloration occurs naturally because of the manufacturing process and because of material composition of the bearings:lead, tin and copper. New bearings can have a bright silver color. An old bearing can have a dark gray color. Bearings remain fully functional through the full range of the color change.

This article describes the acceptability of bearings during all stages of the process of aging. This article provides dealers and customers with the descriptions of different types of bearing stain. Most other discoloration is not harmful to performance. However, the effect on performance and on service life must be determined for stains that result from corrosion of the bearing material. The following information is provided in order to assist in your evaluation of bearings that exhibit stain or corrosion.

Connecting rod bearings and main bearings with a material code of 5 or 8 may not have uniform color on the inside diameter. Refer to Illustration 1. There are three different types of discoloration:

• Gray

• Brown

• Any discoloration except for brown that is found in addition to gray

Refer to the different types of discoloration and the illustrations below in order to determine if the bearing is acceptable.

Gray Discoloration

The intensity of gray on some connecting rods and main bearings is caused by the variation in thickness of the tin flash that is electroplated onto the bearings. The flash protects the steel back of the bearings from corrosion. The bearings have a specification of thickness that requires a maximum of 2.5 microns. If the thickness is 0.5 microns or less, the overlay of lead and tin will penetrate through the tin flash. This will cause the intensity of the color to vary. Gray discoloration has no effect on the function of the bearing. Bearings that have a gray discoloration are acceptable to use.

Note: With enough time and temperature, the flash material will dissipate into the material of the overlay. This dissipation is a natural process of age.

Brown Discoloration

The brown discoloration is caused by a chemical reaction between condensation and deposits on the surface of the bearing. This may lead to corrosion on the bearing surface. Do not use bearings that display brown discoloration. Refer to the illustrations below.

Bearings that Are Unacceptable for Use

Do not use any bearing with any of the following conditions:

• Areas of brown discoloration

• A sharp, distinct border between light gray areas and dark gray areas

• Any purple areas or blue areas

Note: Do not confuse brown discoloration with a rust preventive that is applied at the supplier. The rust preventive adds additional corrosion protection during shipment. Follow the cleaning procedure in Reuse and Salvage Guideline, SEBF8009 in order to determine if the discoloration is a rust preventive.

Bearings that Are Acceptable for Use

Bearings with the following conditions are suitable for use:

• Gray discoloration that changes in intensity from light gray to dark gray without a sharp, distinct border

• Discoloration on the sides of the bearings is acceptable because the side of the bearing is not part of the rotating element of the design.

• If the residue of water can be removed, follow the procedure that is outlined in Reuse and Salvage Guideline, SEBF8009.

Illustration 1	g01357517
(1) Material code

Illustration 2	g01348848

The bearing has a large amount of stain on the surface of the bearing. Do not use the bearing. Refer to Illustration 2.

Illustration 3	g01351807

The bearing indicated that the corrosion (2) has penetrated the tin overlay. Refer to Illustration 3.

Illustration 4	g01366635

The bearing indicated that the corrosion (3) has penetrated the tin overlay. Do not use the bearing. Refer to Illustration 4.

Illustration 5	g01366645

The bearing has stain (4) on the surface. Do not use the bearing. Refer to Illustration 5.

Illustration 6	g01366646

The bearing indicated that the corrosion (5) has penetrated the tin overlay. Do not use the bearing. Refer to Illustration 6.

Illustration 7	g01366651

The bearing indicated that the corrosion (6) has penetrated the tin overlay. Do not use the bearing. Refer to Illustration 7.

Illustration 8	g01366652

Any stain on the edge or corrosion on the edge of the bearing (7) is acceptable. Refer to Illustration 8.

Illustration 9	g01366654

The bearing has stain (8) on the surface. Do not use the bearing. Refer to Illustration 9.