Product Support Program For Repairing Upper Hoist Cylinder Mount Cracking D250E And 350E Articulated Trucks Caterpillar

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.

NOTE: This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS4012" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.

NOTE: This Revised Service Letter replaces the July 11, 1997 Service Letter. Changes have been made to the TERMINATION DATE.

Termination Date

Problem

The upper hoist cylinder mounting may crack during service in the 1166420 and 1299644 Body Group of certain D250E and D350E Articulated Trucks. The mounting can be reinforced.

Affected Product
Model & Identification Number

D250E (5TN1-1066)

D350E (9LR1-324)

Parts Needed

1 - 120-3894 Film (D250E Only)

1 - 120-3895 Film (D250E Only)

1 - 1309878/">130-9878 Film (D350E Only)

1 - 130-9879 Film (D350E Only)

Action Required

See the attached procedure.

Service Claim Allowances

NOTE: This is a 16-hour job.

Parts Disposition

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

Attach.

(1-Rework Procedure)

Rework Procedure
D250E/D350E Upper Hoist Cylinder Mount Repair

PREPARATION WORK

Fabricate two support assemblies from Illustration (1) for the D250E and Illustration (2) for D350E using 1E0065 Steel (Structural, 207 MPa MIN. YIELD) or one of the following:

.... ASTM A108 (GRADE 1018)

.... ASTM A576 (GRADE 1018)

.... JIS G4051 (GRADE S20C)

.... JIS G3101 (GRADE SS41)

Use the following weld procedure for all welding.

Clean the body sides of oil, grease, paint, and dirt in the area to be welded. Welding operator personal protection should be provided to assure that total weld fume in the operators breathing zone within safe limits.

All repair welding operators must be qualified as outlined in the current ANSI/AWS D1.1, or D14.3, or Caterpillar Manufacturing Practices MC1000-105 for the SMAW ( Shielded Metal Arc Welding ) process in the position used for repairing the body. The welding operator must also have used this welding process during the last six months or be re-certified for this process before welding. Documentation must be maintained of the weld operators qualifications.

The body must be at a minimum temperature of 16° C (60° F ) before and during all SMAW and FCAW welding.

The SMAW process shall be used with E7018 (ANSI/AWS A5.5) welding electrode. The weld deposited by these electrodes will have the following minimum mechanical properties:

500 MPa (72 KSI ) Tensile Strength

420 MPa (60 KSI ) Yield Strength

22% elongation in 50 mm (2 inches)

27 J (20 ft lb. ) Notch

Toughness at -29 degrees C (-20 F)

These are low hydrogen electrodes and must be stored in a electrode oven at 250 degrees F when not in use. If the electrodes get damp, scrap or recondition them to manufacturers specifications.

The following chart relates to the electrode diameter and approximate current settings for welding.

Use the direct current electrode positive (DC reverse polarity) polarity setting and remove the slag after every pass.

As an alternate process the FCAW process may be used with E71T-1 (ANSI/AWS A5.20) welding electrode and the manufactures specified shielding gas(es). The weld deposited by these electrodes will have the following minimum mechanical properties:

500 MPa (72 KSI) Tensile Strength

420 MPa (60 KSI) Yield Strength

22% elongation in 50 mm (2 inches)

27 J ( 20 ft lb. ) Notch Toughness at -18 degrees C (0° F)

Welding parameters will vary due to weld position and manufacturer of the welding electrode. For 1.3 mm (0.052 inch diameter) electrode typical welding parameters should be:

Use the direct current electrode positive (DC reverse polarity) polarity setting and remove the slag after every pass.

Attach the welding ground cable directly to the body as. Do not allow welding current to travel through the machine's bearings or hydraulic cylinders. Protect all hydraulic cylinders, struts, hoses, and machined surfaces from sparks or spatter produced by the welding, chipping, and/or grinding operations.

Weld the joint using stringers beads or a weave pattern as desired. Slag each pass to avoid the possibility of slag inclusions. The welding pass size should be manageable, and generally, not exceed two times the electrode diameter. With a single pass of 1/8 inch E7018, the weld metal should be two times the electrode diameter. If the FCAW process is used the welding pass size should not exceed 8 mm ( .312 inch) fillet volume.

BODY PROCEDURE

1. Mark vertical lines on the outside of the body top channel from outer edges of upper hoist cylinder mounting block. (Illustration 3)

2. Transfer lines over and into inside of body side plate.

3. Mark out profile of opening inside of the body, make sure the profile is equal both sides of vertical lines.

Use Illustration (4) for D250E.

Use Illustration (5) for D350E.

4. Flame cut opening, clean up edges thus making filler plate a good fit. Note: If modification is being done on rock liner bodies, remove rock liner from opening.

5. When opening has been flame cut out of body, burn 5 mm chamfer around outer edge and 150 mm hole in center of plate, dress all edges. This plate will become the opening fill plate.

Use Illustration (6) for D250E.

Use Illustration (7) for D350E.

6. Mark position of support gussets, install support assemble in opening and tack in position.

7. Fully weld support assembly to outer channel in both vertical and horizontal positions.

8. Position backing plates inside the opening and tack in place. Use 25 mm x 3 mm flat bar for backing plates.

9. Position filler plate to provide equal gap around the edges and tack weld.

10. Fully weld filler plate at chamfer using 5 mm fillet weld all around. Grind all external welds flush to body wall. (See Illustration 8) If body is equipped with a rock liner replace liner filler at this time.

11. Plug-weld hole in center of filler plate with 5 mm fillet weld. (See Illustration 8)

12. Paint all areas repaired and replace decal or paint area black where decal is located. Decal part numbers are 120-3894 RH and 120-3895 LH for D250E, and 1309878 RH and 130-9879 LH for D350E.

Illustration 1 - D250E

Illustration 2 - D350E

Illustration 3 - D250E and D350E

Illustration 4 - D250E

Illustration 5 - D350E

Illustration 6 - D250E

Illustration 7 - D350E

Illustration 8 - D250E and D350E