The Serpentine Belt May Fail on Certain 320, 320 GCand 323 Excavators {1405} Caterpillar

Excavator

320 (S/N: BR61-UP; ZBN1-UP; YBP1-UP; YCP1-UP; HEX1-UP)

320 GC (S/N: BR41-UP; DKJ1-UP; XBJ1-UP; KTN1-UP; ZBT1-UP)

323 (S/N: BR91-UP; DWE1-UP; DWF1-UP; YBL1-UP; RAZ1-UP)

Reference: SENR3130, "Torque Specifications"

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

The serpentine belt may fail on the machines listed above. Frozen water may cause the alternator to seize. As a result, the belt may be damaged upon starting the machine.

Solution

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Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.

In the event of a failure, or for preventative maintenance, refer to the following rework procedure.

Illustration 1	g06408710
Before rework procedure. (A) 103-0050 Bolt

Illustration 2	g06408707
After rework procedure.

1. If a failure has occurred, replace the serpentine belt with the same part number. Refer to Table 1 for the part number.
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   Illustration 3	g06408697
   (D1) 2X 5 ± 1 mm (0.20 ± 0.04 inch) Forty-Five degree angle. (D2) 75 ± 1 mm (2.95 ± 0.04 inch)

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   Illustration 4	g06413730
   (D3) 21 ± 1 mm (0.83 ± 0.04 inch) (D4) 12.5 mm (0.49 inch) (D5) 102.5 mm (4.04 inch) (D6) 113.5 mm (4.47 inch) (D7) 123 ± 1.5 mm (4.84 ± 0.06 inch) (D8) 2X 3 ± 1.5 mm (0.12 ± 0.06 inch) Forty-Five degree angle. (D9) 5.5 mm (0.22 inch) (D10) 12.5 ± 1.5 mm (0.49 ± 0.06 inch) (D11) 5.5 mm (0.22 inch)

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   Illustration 5	g06408778
   (D9) R 3 ± 1 mm (0.19 ± 0.04 inch) (D10) 3 mm (0.19 inch)

2. Fabricate a cover plate as per the dimensions shown in Illustration 3, Illustration 4, and Illustration 5.

   Note: The cover plate should only be fabricated using the following material grades.

   • ASTM A108: Grade 1018

   • EN10025-2: Grade S235JR

   • JIS G3101: Grade SS400

3. Remove the two alternator flange bolts (A).

   Note: Do not discard the bolts.

4. Install the newly fabricated cover plate as shown in Illustration 2.

5. Install the bolts and torque the bolts to 55 ± 10 N·m (41 ± 7 lb ft).