PRODUCT IMPROVEMENT PROGRAM FOR INSPECTING AND REWORKING THE FRONT SUSPENSION CYLINDER HOUSINGS ON CERTAIN 773D OFF-HIGHWAY TRUCKS Caterpillar

PRODUCT IMPROVEMENT PROGRAM FOR INSPECTING AND REWORKING THE FRONT SUSPENSION CYLINDER HOUSINGS ON CERTAIN 773D OFF-HIGHWAY TRUCKS

Usage:

REBE5224-02

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01Jun2009

(Revised 15Jun2009)

D-175

O-182

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*Safety*	PRODUCT IMPROVEMENT PROGRAM FOR INSPECTING AND REWORKING THE FRONT SUSPENSION CYLINDER HOUSINGS ON CERTAIN 773D OFF-HIGHWAY TRUCKS
0353 7201 0679 0372		PI10759

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NOTE:

This Program must be administered as soon as possible. When reporting the repair, use "PI10759" 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 "PI10759" 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:	This Revised Service Letter replaces the 01Jun2009 (Revised 02Jun2009) Service Letter. Changes have been made to Action Required and Rework Procedure.

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PROBLEM

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The existing 298-3925 Front Suspension Cylinder Housing may fail due to weld quality and fatigue. The result of weld fatigue could potentially be seen as cracks in the welds around the Housing. This could result in a structural failure of the Suspension Cylinder with the potential for injury or death.

AFFECTED PRODUCT

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Model	Identification Number
773D	NBJ00200-00418

PARTS NEEDED

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Qty	Part Number	Description
12	1D4640	BOLT
2	5F9338	BOLT
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 40% 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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Refer to the Service Manual if/as necessary.

Read and understand the following instructions thoroughly before proceeding with any action.

1. Immediately remove from service and inspect for cracks on machines that are listed under first priority inspection list (Refer Image 2). Inspect for cracks as per the weld inspection procedure attached with the Service letter. Schedule inspection for machines appearing in second priority list (Refer Image 3) and third priority list (Refer Image 4) as soon as possible.

2. Refer Image 1 for areas to be inspected on the front suspension cylinder housing.

3. Weld inspection procedure and weld rework procedure are attached with the service letter.

4. Inspect all Ribs-to-Flange welding, Ribs-to-Housing Welding, Tube-to-Tube Welding, Flange-to-Housing outside vertical welding and Flange-to-Housing inside vertical welding as per the weld inspection procedure. If cracks are noticed and weld repair is not permissible, remove the machine from service and please contact Caterpillar Product Analyst at +919940150313 / +919791045215 for additional information.

5. Prepare a detailed inspection report for every front suspension cylinder and send it to your product analyst/service engineer. Refer Image 5 for the format of report to be provided. Include photographs of all cracks noticed during the inspection.

6. Continue visual inspection for the entire affected product every 500 Hours. Be sure to clean the housing prior to visual inspection.

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Image1

Image2

Image3

Image4

Image5

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%
100%	100%	0%	0%	0%	0%

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NOTE: This is a 2.0-hour job
The 2.0 hour allowance is for inspecting each front suspension cylinder housing for crack using dye penetrant method. In case crack is detected during inspection and determined repairable as per the weld repair procedure an additional 17.0 hours per cylinder will be allowed. An additional allowance of 1.0 hour per front suspension cylinder will apply for every 500 hour visual inspection until Caterpillar's permanent corrective action is in place. Front suspension cylinder mounting bolts need not be replaced with every inspection.

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PARTS DISPOSITION

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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

SAFETY - PRODUCT IMPROVEMENT PROGRAM FOR INSPECTING AND REWORKING THE FRONT SUSPENSION CYLINDER HOUSINGS ON CERTAIN 773D OFF-HIGHWAY TRUCKS

MODELS INVOLVED - 773D OFF-HIGHWAY TRUCKS

Dear Caterpillar Product Owner:

The front suspension cylinder housing needs to be inspected / reworked on the products listed below. The existing front suspension cylinder housing may fail due to weld quality and fatigue. The result of weld fatigue could potentially be seen as cracks in the welds around the Housing. This could result in a structural failure of the Suspension Cylinder with potential for injury or death. 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 01Jun2009 when scheduling this service.

We regret the inconvenience this may cause you, but urge you to have this service performed for your added safety and satisfaction.

Caterpillar Inc.

Identification #(s)

Attached to 01Jun2009 Service Letter

Rework Procedure

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WELD INSPECTION PROCEDURE

Refer to the Service Manual if/as necessary.

1. Park the Truck in suitable location for inspection.

2. Wash thoroughly the Front suspension cylinder on either side of the Truck and
remove any dirt, oil and grease prior to inspection.

3. Perform a Visual inspection on the following areas for any visible cracks. Refer Image 1.1.1 for areas of inspection.
a. All Ribs-to-Flange Welding
b. All Ribs-to-Housing Welding
c. Flange-to-Housing outside vertical welding
d. Tube-to-Tube welding

4. Perform Dye Penetrant inspection on the following areas as per the procedure attached below. Refer Image 1.1.1 for areas of inspection.
a. All Ribs-to-Flange Welding
b. All Ribs-to-Housing Welding
c. Flange-to-Housing outside vertical welding
d. Tube-to-Tube welding

5. If inspection reveals no cracks in the areas mentioned below
a. All Ribs-to-Housing Welding
b. Flange-to-Housing outside vertical welding
c. Tube-to-Tube welding
and up to three cracks in Ribs-to-Flange welding, refer RENR8412 for removal of Front Suspension Cylinder.

6. After removing the Front Suspension Cylinder, perform visual inspection of Flange-to-Housing inside vertical welding (rear of front suspension cylinder housing).

7. Weld repairs are acceptable only on Rib-to-Flange welding. If cracks are observed in more than three Ribs, weld repair is not permissible. If crack is noticed in Flange-to-Housing inside vertical welding, weld repair is not permissible. If cracks are noticed in other areas of the Front Suspension Cylinder Housing, weld repairs are not permissible.

Image1.1.1

DYE PENETRANT INSPECTION PROCEDURE

Dye penetrant testing is non-destructive testing method for detecting discontinuities open to the surface such as cracks, seams, laps, surface weld flaws, etc. Refer Image 1.1.1 for the areas of inspection.

MATERIALS REQUIRED

1. CLEANER: This removes dirt before dye application and dissolves the penetrant making it possible to wipe the surface clean.
2. PENETRANT: This solution is highly visible, and will seep into openings at the surface of a part by means of capillary action.
3. DEVELOPER: This provides a blotting action, bringing the penetrant out of the discontinuities and providing a contrasting background to increase the visibility of the penetrant indications.

INSPECTION METHOD

1. Remove any loose scale and dirt by wiping. Remove oil using solvents.
2. Wipe the area to inspect with a solvent dampened cloth to remove remaining dirt and allow the area to dry.
3. If there is a visible crack remove paint using paint remover or grinding.
4. Apply penetrant by spraying to the entire area to be examined.
5. Allow 10 to 15 minutes for penetrant to soak.
6. After the penetrant has been allowed to dwell, remove most of the excess penetrant with clean, dry wipes. The last traces of penetrant should be removed with the cleaner solvent dampened cloth or wipe. Allow the area to dry thoroughly.
7. Apply an even, thin layer of developer over the area being inspected. A few very thin layers are a better application method than one thicker
layer. Allow the developer to dry completely for 10 ? 15 minutes before inspecting for surface discontinuities.
8. The developer will act to draw entrapped penetrant out of the discontinuity. A red stain on the developer indicates a possible surface discontinuity.
9. Clean the area of application of the developer with solvent cleaner.

REWORK PROCEDURE FOR RIBS TO FLANGE WELDING

NOTE: Weld repairs are acceptable only on Rib to Flange welding. If cracks are observed in more than three Ribs, weld repair is not permissible. If crack is noticed in flange to housing inside vertical welding, weld repair is not permissible. If cracks are noticed in other areas of the Front Suspension Cylinder Housing, weld repairs are not permissible.

Refer to the following for proper safety and startup procedures prior to any welding:

SEBU8020 - "WELDING ON MACHINES AND ENGINES WITH ELECTRONIC CONTROLS
SEBU8020 - "FIRE PREVENTION AND EXPLOSION PREVENTION"
REHS1841 - "GENERAL WELDING PROCEDURES"

CONSUMABLE'S REQUIRED FOR REWORK (Refer Image 1.3.1)

Image1.3.1

WELDER QUALIFICATION / SAFETY
All welders must be qualified for fillet welding in 2F positions as outlined in the current ANSI/AWS standards. The welding operator must also have used the welding process during the last six months or be re-certified for this purpose before welding. Personal protection should be provided to assure that total weld fume in the operator?s breathing zone is within safe limits.

ELECTRODE / CHARACTERISTICS
The MMAW (Manual Metal Arc Welding) process should be used with E7018 welding electrode. The weld deposited by these electrodes will have the following minimum mechanical properties:
TENSILE STRENGTH 480 MPa
YIELD STRENGTH 400 Mpa
ELONGATION 22%
These are low hydrogen electrodes and must be stored in oven at 120 degree Celsius (248 degrees Fahrenheit) when not in use.

ELECTRODE DIAMETER AND CURRENT SETTINGS FOR WELDING (Refer Image 1.4.1)
Remove slag after every pass using chipping hammer and wire brush.

Image1.4.1

PREPARATION FOR WELD REWORK

1. Refer RENR8412 for removal of Front Suspension Cylinder. Orient the front suspension cylinder so weld can be repaired in 1F or 2F position.
2. Clean the area to be welded of oil, grease, paint, and dirt. Attach the welding ground cable directly to the suspension strut flange nearer to the welding area.
3. Protect all machined surfaces from sparks or spatter produced by the welding,
chipping, and/or grinding operations.

WELD REWORK PROCEDURE

1. Remove the cracked fillet welding completely from the Rib by gouging till root weld and ensure with Dye Penetrant the crack is removed completely.
2. Weld to 12 mm fillet size and ensure with weld fillet gauge.
3. Use a small grinder to blend the weld in order to create a smooth transition between Rib and Flange.
4. After the rework is completed refer RENR8412 to install the Front Suspension Cylinder on the Truck.
5. Paint as required.