PRODUCT SUPPORT PROGRAM FOR REPLACING THE DIFFERENTIAL THRUST WASHERS ON CERTAIN 793D AND 793F OFF-HIGHWAY TRUCKS Caterpillar
PRODUCT SUPPORT PROGRAM FOR REPLACING THE DIFFERENTIAL THRUST WASHERS ON CERTAIN 793D AND 793F OFF-HIGHWAY TRUCKS
Usage:
TEBE2008-05
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04Dec2014
(Revised 03Jun2016)
U-725
A-539
D-639
O-632
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After Failure Only
PRODUCT SUPPORT PROGRAM FOR REPLACING THE DIFFERENTIAL THRUST WASHERS ON CERTAIN 793D AND 793F OFF-HIGHWAY TRUCKS
3258
PS52829
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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 can only be administered after a failure occurs.
The decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS52829" as the Part Number
and "7755" as the Group Number. Use "96" as the Warranty Claim Description Code and use "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 04Dec2014 (Revised 06Apr2015) Service Letter. Changes have been made to remove the Parts Stock Action.
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TERMINATION DATE
31Dec2016
PROBLEM
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The 309-7671 Differential Thrust Washers on certain 793D and 793F Off-Highway Trucks can experience excessive wear prior to planned component rebuild. If the thrust washers are allowed to wear excessively, misalignment will occur causing damage to the differential housing and gears.
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 2% 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 2% 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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Once three (3) oil samples are taken and analyzed to find 100 ppm or more of copper, then this program can be applied to the truck differential in question. Changing the oil at least once after copper exceeds 100 ppm and monitoring future SOS samples is recommended before applying this program.
Refer to the Service Manual as necessary. Reference RENR8328 "793D Off-Highway Truck Power Train" Disassembly and Assembly to remove the differential from the truck and the disassembly of the differential assembly to access the thrust washer for 793D trucks.
Refer to the Service Manual as necessary. Reference KENR8397 "793F Off-Highway Truck Power Train" Disassembly and Assembly to remove the differential from the truck and the disassembly of the differential assembly to access the thrust washer for 793F trucks.
Some general guidelines regarding SOS results should be followed before the decision is made to remove the complete differential group for repairs.
Monitor the SOS samples. Only remove the differential for repair if you find the following conditions:
... Copper levels in three (3) consecutive oil samples are greater than 100 ppm AND ... Differential operational hours are greater than 5000 hours since new or rebuild to account for early hour break-in.
When submitting the warranty claim after the work is complete, the dealer must collect and include the following information in the SIMSi report:
... The three (3) SOS samples ... Current differential hours ... Thrust washer thickness measurements ... Pictures of thrust washer wear
In addition to filing a SIMSi report, please also send SOS sample history, current differential hours, thrust washer thickness measurements and thrust washer pictures to Lower Power Train Service Engineer Tom Gregg at gregg_thomas_j@cat.com.
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SERVICE CLAIM ALLOWANCES
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Product smu/age whichever comes first
Caterpillar
Dealer Suggested
Customer Suggested
Parts %
Labor Hrs%
Parts %
Labor Hrs%
Parts %
Labor Hrs%
*******Group 1*******
0-6000 hrs, 0-12 mo
100.0%
100.0%
0.0%
0.0%
0.0%
0.0%
6001-12000 hrs, 13-24 mo
33.0%
50.0%
0.0%
0.0%
50.0%
50.0%
12001-18000 hrs, 25-48 mo
13.0%
25.0%
0.0%
0.0%
65.0%
75.0%
NOTE: This is a 44.0-hour job for Group 1
If there has been a previous repair, part age/hours will apply. Retain a copy of the previous repair invoice in the dealer's records for audit purposes, and specify repair date and machine hours in the "Additional Comments" section of the warranty claim.
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Product smu/age whichever comes first
Caterpillar
Dealer Suggested
Customer Suggested
Parts %
Labor Hrs%
Parts %
Labor Hrs%
Parts %
Labor Hrs%
*******Group 2*******
0-6000 hrs, 0-12 mo
100.0%
100.0%
0.0%
0.0%
0.0%
0.0%
6001-12000 hrs, 13-24 mo
33.0%
50.0%
0.0%
0.0%
50.0%
50.0%
12001-18000 hrs, 25-48 mo
13.0%
25.0%
0.0%
0.0%
65.0%
75.0%
NOTE: This is a 44.0-hour job for Group 2
If there has been a previous repair, part age/hours will apply. Retain a copy of the previous repair invoice in the dealer's records for audit purposes, and specify repair date and machine hours in the "Additional Comments" section of the warranty claim.
PARTS DISPOSITION
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Rework Procedure
Group Number 2
Repair Procedure for 793D Differential Follow RENR8328 Differential and Bevel Gear ? Assemble until Step 57 Illustration 30 then refer to images below for proper orientation of the new 6I-9248 Bearing-Thrust, 6I-9249 Race-Thrust, 448-0727 Gear-Bevel and 466-3321 Housing As-Diff on the flange half side of the differential.
Image1.1.1
Continue using RENR8328 Differential and Bevel Gear ? Assemble at Step 60 Illustration 32 until Step 64 Illustration 38 then refer to images below for proper orientation of the new 6I-9248 Bearing-Thrust, 6I-9249 Race-Thrust, 448-0727 Gear-Bevel and 466-3321 Housing As-Diff on the flange half side of the differential.
Image1.2.1
Note: The 6I-9249 Thrust-Race can be fixed in place on the 466-3321 Housing by using a small amount of 60W oil or pure petroleum jelly. Note: Ensure the 6I-9249 Thrust-Race does not come out of place when mating the 466-3321 Housing As-Diff (plain half side) onto the 466-3321 Housing As-Diff (flange half side).
After the 466-3321 Housing As-Diff (plain half side) is mated refer back to RENR8328 Differential and Bevel Gear ? Assemble at Step 67 Illustration 39 and continue full assembly of the differential.
Group Number 1
Special Instruction for 793F Differential Follow KENR8397 Differential and Bevel Gear ? Assemble until Step 42 Illustration 21 then refer to images below for proper orientation of the new 6I-9248 Bearing-Thrust, 6I-9249 Race-Thrust, 448-0727 Gear-Bevel and 466-3321 Housing As-Diff on the flange half side of the differential.
Image2.1.1
Continue using KENR8397 Differential and Bevel Gear ? Assemble at Step 44 Illustration 23 until Step 49 Illustration 29 then refer to images below for proper orientation of the new 6I-9248 Bearing-Thrust, 6I-9249 Race-Thrust, 448-0727 Gear-Bevel and 466-3321 Housing As-Diff on the flange half side of the differential.
Image2.2.1
Note: The 6I-9249 Thrust-Race can be fixed in place on the 466-3321 Housing by using a small amount of 60W oil or pure petroleum jelly. Note: Ensure the 6I-9249 Thrust-Race does not come out of place when mating the 466-3321 Housing As-Diff (plain half side) onto the 466-3321 Housing As-Diff (flange half side).
Note: The dowels that are shown above are used in Step 50 of KENR8397 in order to engage the slots in four retainers (45) of pinion gear assemblies (38) that are shown in Illustration 27 of KENR8397. After the 466-3321 Housing As-Diff (plain half side) is mated refer back to KENR8397 Differential and Bevel Gear ? Assemble at Step 50 Illustration 30 and continue full assembly of the differential.
