PRODUCT IMPROVEMENT PROGRAM FOR INSPECTING/REWORKING THE FRONT GEAR TRAIN ON C175-16 AND C175-20 ENGINES INSTALLED IN CERTAIN 793F AND 797F OFF-HIGHWAY TRUCKS Caterpillar
PRODUCT IMPROVEMENT PROGRAM FOR INSPECTING/REWORKING THE FRONT GEAR TRAIN ON C175-16 AND C175-20 ENGINES INSTALLED IN CERTAIN 793F AND 797F OFF-HIGHWAY TRUCKS
Usage:
REBE6371-01
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26Aug2010
(Revised 22Dec2010)
U-350
A-274
D-299
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Priority
PRODUCT IMPROVEMENT PROGRAM FOR INSPECTING/REWORKING THE FRONT GEAR TRAIN ON C175-16 AND C175-20 ENGINES INSTALLED IN CERTAIN 793F AND 797F OFF-HIGHWAY TRUCKS
1151 1162 1206
PI31793
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NOTE:
This Program must be administered as soon as possible.
When reporting the repair, use "PI31793" as the Part Number and "7751" as the Group Number, "56" as the Warranty Claim Description Code
and "T" as the SIMS Description code. Exception: If the repair is done after failure, use "PI31793" as the Part Number, "7751" as the Group Number,
"96" as the Warranty Claim Description Code, and "Z" as the SIMS Description Code.
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NOTE:
The information supplied in this service letter may not be valid after the termination date of this program.
Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
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NOTE:
This Revised Service Letter replaces the 26Aug2010 Service Letter. Changes have been made to Parts Needed, Service Claims Allowance, and Rework Procedure to show additional detail for the upper right hand drive.
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COMPLETION DATE
TERMINATION DATE
28Feb2011
31Aug2011
PROBLEM
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The front gear train needs to be inspected/reworked on certain C175-16 and C175-20 engines installed in 793F and 797F off-highway trucks. The existing auxilary drive gears may have been assembled with low bolt torque that can cause a front gear train failure.
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 35% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer.
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 35% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer.
ACTION REQUIRED
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Inspect the front gear train bolts for proper torque.
Refer to the attached Rework Procedure.
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OWNER NOTIFICATION
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U.S. and Canadian owners will receive the attached Owner Notification.
SERVICE CLAIM ALLOWANCES
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Caterpillar
Dealer Suggested
Customer Suggested
Parts %
Labor Hrs%
Parts %
Labor Hrs%
Parts %
Labor Hrs%
*******Group 1*******
100%
100%
0%
0%
0%
0%
NOTE: This is a 45.0-hour job for Group 1
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Caterpillar
Dealer Suggested
Customer Suggested
Parts %
Labor Hrs%
Parts %
Labor Hrs%
Parts %
Labor Hrs%
*******Group 2*******
100%
100%
0%
0%
0%
0%
NOTE: This is a 45.0-hour job for Group 2
PARTS DISPOSITION
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.
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COPY OF OWNER NOTIFICATION FOR U.S. AND CANADIAN OWNERS
XYZ Corporation 3240 Arrow Drive Anywhere, YZ 99999
PRIORITY - INSPECTION OF THE FRONT GEAR TRAIN BOLTS
MODELS INVOLVED - 793F AND 797F
Dear Caterpillar Product Owner:
The engine front gear train bolts need to be inspected for adequate torque on the products listed below. The existing bolts may have inadequate torque and could result in a gear train failure. You will not be charged for the service performed.
Contact your local Caterpillar dealer immediately to schedule this service. The dealer will advise you of the time required to complete this service.
Please refer the dealer to their Service Letter dated 26Aug2010 when scheduling this service.
We regret the inconvenience this may cause you, but urge you to have this service performed as soon as possible to prevent unscheduled downtime.
Caterpillar Inc.
Identification #(s)
Attached to 26Aug2010 Service Letter
Rework Procedure
1. Refer to the C175 Disassembly & Assembly manual (KENR6052) for instructions on removal and installation of the jacket water pump, auxiliary water pump, air compressor, and idler gears (front).
NOTE: Be careful not to damage the shaft of the water pump and the internal ceramic seal of the water pump.
2. Remove adapter, and push shaft in drive toward rear of engine to allow access to the head of the bolts (Image 1.1.1).
Image1.1.1
3. Perform a return to mark check on all 8T-2392 Bolts (Qty 24) on both the right (high pressure fuel pump) side and left (oil pump) side (Image 1.2.1). Utilize a modified 8mm ball hex socket driver, (Snap-On Part Number: FABLM8E). The section of the driver shaft near the ball hex has been ground to remove the flats of the hex (Image 1.2.2). Mark the start position of each bolt prior to carrying out this procedure. Set the torque wrench to the static torque specification of 35 Nm. Perform a Return-to-Mark check on each of the bolts (Image 1.2.3).
- If any of the bolts turn past the start position before reaching the 35 Nm static torque specification, the bolts had low torque, proceed to Step 4 and complete Steps 4, 5, 6, and 7.
- If the bolts do not return to the start position before reaching the 35 Nm static torque specification, then retighten the bolts to 55 Nm +/- 10 Nm and re-install the jacket water and auxiliary water pumps, as the bolts had adequate torque and no further action is necessary for the lower drive gears. Proceed to step 8 of this procedure.
Image1.2.1
Image1.2.2
Image1.2.3
4. - For 793F, remove the 245-1346 and 244-8593 Gears on the high pressure fuel pump side (right hand side) and the 244-8593 Gear on the oil pump side (left hand side) and inspect for fretting on the gear face (Image 1.3.2).
- For 797F, remove the 255-4445 and 244-8593 Gears on the high pressure fuel pump side (right hand side) and the 244-8593 Gear on the oil pump side (left hand side) and inspect for fretting on the gear face (Image 1.3.1).
Image1.3.1
Image1.3.2
5. If light fretting is found, clean-up (stone) the gear faces, reinstall, and retighten all 8T-2392 Bolts to 55 Nm +/- 10 Nm. All material transfer should be removed to ensure a flat mounting surface.
NOTE: The fretting is considered to be light fretting if the fretting is not continuous between the bolt holes and the fretting does not extend past the centerline of the bolt holes (Image 1.4.1).
Image1.4.1
6. If heavy fretting is found, replace the affected gears with new parts, replace all the 8T-2392 bolts and retighten to 55 Nm +/- 10 Nm.
NOTE: The fretting is considered to be heavy fretting if the fretting extends past the centerline of the bolt holes (Image 1.5.1).
Image1.5.1
7. Re-install the jacket water and auxiliary water pumps.
8. Remove the air conditioner belt guard.
9. Remove the air conditioner drive belt.
10. Remove the 300-8570 air conditioner drive pulley (Image 1.6.1).
Image1.6.1
11. Remove the air compressor (Image 1.7.1).
NOTE: Do not disconnect air lines until the air pressure in the system is at zero.
Image1.7.1
12. Remove the 348-7081 adapter assembly (Image 1.8.1).
Image1.8.1
13. Remove the 259-6312 shaft and 245-1346 gear assembly (Image 1.9.1 and 1.9.2).
Image1.9.1
Image1.9.2
14. Tighten the 8T-2392 bolts (Qty 24) to 55 Nm +/- 10 Nm (Image 1.10.1 and 1.10.2).
Image1.10.1
Image1.10.2
NOTE: The following method can be used to retain the shaft/gear assembly while re-torqueing the 8T-2392 bolts. Remove the shaft/gear assembly and clean both ends of the shaft. Flip the shaft end-for-end and re-install the shaft assembly in the opposite direction so that the bolt heads for the 8T-2392 bolts are visible. This orientation provides a good method to hold the shaft assembly while allowing access to the bolt heads for re-torqueing.
15. Remove the shaft/gear assembly. Install a new 235-2484 lip seal. Re-install the shaft/gear assembly in the correct orientation.
