PRODUCT SUPPORT PROGRAM FOR REPLACING THE WELD OR REPAIRING THE FRAME AT THE TORQUE TUBE TO WINDOW PLATE WELD JOINT ON THE MID FRAME SECTION ON CERTAIN 793F, 793F AC, 793F CMD, AND 793F XQ OFF-HIGHWAY TRUCKS Caterpillar

PRODUCT SUPPORT PROGRAM FOR REPLACING THE WELD OR REPAIRING THE FRAME AT THE TORQUE TUBE TO WINDOW PLATE WELD JOINT ON THE MID FRAME SECTION ON CERTAIN 793F, 793F AC, 793F CMD, AND 793F XQ OFF-HIGHWAY TRUCKS

Usage:

TEBE3972-05

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01Dec2015

(Revised 11Apr2017)

U-638

A-462

D-562

O-551

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Before/After	PRODUCT SUPPORT PROGRAM FOR REPLACING THE WELD OR REPAIRING THE FRAME AT THE TORQUE TUBE TO WINDOW PLATE WELD JOINT ON THE MID FRAME SECTION ON CERTAIN 793F, 793F AC, 793F CMD, AND 793F XQ OFF-HIGHWAY TRUCKS
7050 7051 0679		PS44926

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NOTE:

Caterpillar’s obligations under this Service Letter are subject to, and shall not apply in contravention of, the laws, rules, regulations, directives, ordinances, orders, or statutes of the United States, or of any other applicable jurisdiction, without recourse or liability with respect to Caterpillar.

NOTE:

This Program must be administered either before or after failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS44926" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and "T" as the SIMS Description code. If administered after failure, use "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 01Dec2015 (Revised 24Mar2016) Service Letter. Changes have been made to the Termination Date and Service Claim Allowances.

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TERMINATION DATE

31Jan2020

PROBLEM

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Frame cracking has been reported at the torque tube to window plate joint on the mid-frame area of certain 793F, 793F AC, 793F CMD, and 793F XQ Off-Highway Trucks. This program applies the weld joint that connects the torque tube to the outer window plates. Cracks in the joint are being reported between 8,000 and 14,000 hours after the 12 gusset update. The life hours that this joint achieves is based on multiple factors including site conditions, operational practices, and rework quality. Before applying this program please contact Large Off-Highway Truck Product Support for additional repair recommendations. Cracks that go unidentified or identified and left unattended can lead to invasive frame repairs and/or severe frame damage.

AFFECTED PRODUCT

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Model	Identification Number
793F	SSP00112-00943
793F AC	EMD00075-00077
793F CMD	RBT00111-00164
793F XQ	SND00100-00131

PARTS NEEDED

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Qty	Part Number	Description
1	4317565	PLATE (After Failure Only)
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 32% 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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There are three repair options listed in the rework procedure. Please contact Large Off-Highway Truck Product Support to discuss these options in order to determine the best repair option for each individual case.

A Level 1 Plus repair is a proactive weld replacement strategy that can be applied before a crack initiates. This will allow for the scheduled replacement of the weld joint and reduce unplanned machine stoppages. Site experience with the 12 gusset frame design and hours after the 12 gusset update are the best indicators to this weld joint's life.

For a Level 1 Plus repair perform a visual and magnetic particle inspection on the weld at the rear half of the weld joint. Repair if/as required. Excavate and replace the weld on the front half of the weld joint per the specifications in REHS7995.

A Level 1 repair is an after failure repair that is completed without removing the window plate. Thus it is the least invasive and quickest after failure repair to complete. If the crack propagates into the window plate or the weld joint configuration is damaged during crack excavation this repair option will have reduced life as compared to the original joint. If the crack is found, properly excavated and repaired prior to propagating into the window plate, this repair option will have approximately equal life to the original joint if it was welded to the specifications in REHS7995.

For a Level 1 repair excavate and repair crack per the specifications in the Rework Procedure.

A Level 2 repair is an after failure repair that requires the window plate to be replaced. Thus it is a more invasive and lengthy repair to complete. This repair option will have approximately equal life to the original joint, if it was welded to the specifications in REHS7995.

For a Level 2 repair, procure and replace the window plate per the specifications listed in Repair Option B in Special Instruction REHS7995.

Note: If the weld joint on one side fails it is recommended to perform a Level 1 Plus repair on the opposite side.

If the crack characteristics are not covered by the aforementioned rework procedures please contact your local Caterpillar Service Representative for further instruction.

Refer to Image1 for torque tube to window plate joint location and Image2 for an example of a left hand side torque tube to window plate weld crack.

Note: This letter is not applicable if the machine has been fitted with a volcano casting center tube.

Note: Refer to the machines Operation and Maintenance Manual for frame inspection frequency.

Note: Full frame inspection and repair guidelines can be found in Special Instruction REHS7193 - Procedure for the Inspection, Repair, and Component Replacement on the Frame of the 793F, 793F AC and the 793F Command For Hauling Off-Highway Trucks {0679, 7051}.

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Image1

Image2

SERVICE CLAIM ALLOWANCES

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Product smu/age whichever comes first	Caterpillar		Dealer Suggested		Customer Suggested
Product smu/age whichever comes first	Parts %	Labor Hrs%	Parts %	Labor Hrs%	Parts %	Labor Hrs%
0-60000 hrs, 0-120 mo	100.0%	100.0%	0.0%	0.0%	0.0%	0.0%

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NOTE: This is a 6.0-hour job
Begin applying Level 1 Plus repairs as required by site conditions. A Level 1 Plus repair option can be completed at 10,000 hours after the 12 gusset update and every 10,000 hours thereafter. The letter may be claimed each time the machine is repaired while the letter is open. The service claim allowance listed is for completing a Level 1 Plus repair on one side or excavating a crack in the weld and replacing the weld. An additional 6 hours will be allowed to drain and fill fluid compartments for all repairs. An additional 4 hours of labor will be allowed for a Level 1 repair for repairing cracks that propagate from the torque tube weld into the window plate. An additional 15 hours of labor will be allowed for removing and installing the fuel tank to complete a Level 1 Plus, Level 1 or 2 repair on the machine's left side. An additional 23 hours of labor will be allowed for removing and installing the hydraulic tank to complete a Level 1 Plus or Level 1 repair on the machine's right side. An additional 36 hours of labor will be allowed for removing and installing the hydraulic tank and associated components to complete a Level 2 repair on the machine's right side. An additional 30 hours of labor will be allowed to complete a Level 2 repair for replacing either the right or left side window plate. It is required to attach pre-repair pictures showing the original weld, any cracking and the fillet weld size at the torque tube to window plate joint to SIMSi when submitting the warranty claim. It is required to attach after-repair pictures in SIMSi of the torque tube to window plate fillet weld, with a fillet weld gauge visible to confirm the size, and of the window plate groove weld, when submitting the warranty claim. For welds from previous repairs that are found to be undersized, or otherwise do not meet the weld acceptance criteria found in REHS7995, the dealer will be responsible for 50% of the labor hours needed to bring those welds into conformance. An allowance of $1,500 for ultrasonic inspection may be claimed for level 2 repairs only. The ultrasonic inspection must be performed by a certified ultrasonic inspection technician and in accordance with the criteria specified in REHS7995. This program may be applied multiple times if necessary.

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PARTS DISPOSITION

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Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.

Rework Procedure

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Refer to the "Procedure to Replace the Weld or Repair the Frame at the Torque Tube to Window Plate Weld Joint on the Mid Frame Section" section in Special Instruction REHS7995 "Procedure to Inspect and Repair the Center Section Frame on Certain 793F Off-Highway Trucks".