Radiator Fan Shaft Bearing Set Screw Inspection and Installation {1353, 1356} Caterpillar

Electric Power Generation

3516C GEN SET (S/N: SBK1-UP)

C175-16 GEN SET (S/N: WYB1-UP)

Engine

3512C (S/N: YBD1-UP; SBG1-UP; LYH1-UP)

3516C (S/N: SKC1-UP; SBJ1-UP; SFJ1-UP; SEK1-UP)

C175-16 (S/N: WYC1-UP)

C175-20 (S/N: BXR1-UP)

Generator Set

3516E (S/N: LCK1-UP)

Introduction

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

The fan drive shaft support pillow block bearing collar set screw securing the bearing in the correct position on the fan shaft may become loose and the shaft may move back toward the engine due to the air flow force. The set screw torque was found set incorrectly, or the set screws were not properly seated in the shaft dimples.

Affected Radiator Part Numbers

Installation Procedure

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Illustration 1	g06149455

1. Remove the fan shaft bearings cover. Loosen and remove the four bolts and nuts holding cover. Lift bearing cover off bearings to access the shaft pillow bearings. Refer to Illustration 1.
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   Illustration 2	g06149457
   Browning Brand

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   Illustration 3	g06149458
   Dodge Brand

2. Identify the bearing brand to determine the set screw torque. Refer to RED nameplate for brand color difference between brands. Refer to Illustration 2 and 3.
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   Illustration 4	g06149485

3. Loosen the belts and rotate the fan and align/position one set of set screws on top of the shaft. Take an Allen wrench and remove the four set screws to check for alignment. Refer to Illustration 4.

4. Rotate the fan 120 degrees until the second set of four set screws are on top of the shaft. Use an Allen wrench and remove the second set of screws to check for alignment.

   Note: There may be a third hole on the bearing collar for a set screw located 120 degrees apart. This hole is not used and will remain without a set screw.

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   Illustration 5	g06149486

5. Verify that all dimple holes in the shaft line up with the holes in the pillow block bearing. You may need to rotate the shaft to make sure to observe all set screws on each pillow bearing. All set screw holes must be concentric with fan shaft dimples, refer to Illustration 5.
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   Illustration 6	g06149492
   Correct

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   Illustration 7	g06149493
   Wrong (Needs In/Out adjustment)

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   Illustration 8	g06149495
   Wrong (Needs rotating adjustment)

6. If the set screws are found positioned off the center of the dimple, reposition the fan shaft to properly center the dimples and the set screw holes. If only one pillow bearing set screws are off the dimple center position, loosen the pillow bearing mounting bolts and reposition it to match the shaft. Refer to Illustration 6, 7, and 8. Tighten the pillow block bearing bolts to Cat torque specs when done.
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   Illustration 9	g06149502

7. After all set screws holes and shaft dimples are aligned, reinstall the set screws. Apply Loctite 242 to set screws. Refer to Illustration 9.

8. Tighten down set screws to the torque required for each brand of the pillow bearing. Refer to the Table 2. Torquing set screws to mid-range of torque values is preferred.
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   Table 2

   Browning Bearings			Dodge Bearings
   Set Screw Diameter/Pitch	Torque lb-ft	Torque N-m	Set Screw Diameter/Pitch	Torque lb-ft	Torque N-m
   1/2"-20	34 to 45	46 to 61	1/2"-13	48 to 56	65 to 76

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   Illustration 10	g06149534

9. Follow the torque sequence described below for each pillow block bearing collar. Refer to Illustration 10.

   A. Torque the set screw X to one half of the required torque.

   B. Torque the set screw Y to full torque.

   C. Torque the set screw X to full torque.

   D. Repeat on the other side of the bearing, and on the second pillow bearing.

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   Illustration 11	g06149537
   (Z) Mark the set screw.

10. Mark set screws with white paint pen after each one is torqued. Refer to Illustration 11.

11. Tension the fan belts. Refer to Specifications , RENR9362 , "Belt Tension Chart".

12. Observe the pillow bearing grease condition. If excessive purging of the grease from the bearing is observed. Check to make sure this is not caused by over-greasing during servicing. Then provide the Product Status Report (PSR), an inspection information and pictures (prior to any disassembly) and send to CPI@cat.com.