Product Support Program For Repairing The Fabricated Rear Wheel Assemblies On Certain 789B Trucks 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 "PS5564" 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.

NOTE: Although this Program is to be administered as described above on the Affected Product, Parts Stock action should be completed as soon as possible.

Termination Date

Problem

The 1250061/">125-0061 Rear Wheel Assembly on certain 789B Trucks may fail in the weld joining the wrapper plate to the hub casting. The crack could be on the original rear wheel or the rework to the thicker (16mm) wrappers. The crack has usually surfaced in the weld metal on the wrapper plate side.

A new wider 16mm wrapper is required for the two piece fabricated rear wheel assemblies for the 789B trucks. Ref. 1250061/">125-0061 wheel as.

Affected Product
Model & Identification Number

789B (7EK399-659)

Parts Needed

1 - 1690505 SECTION

1 - 1690506 SECTION

2 - 1690507 PLATE

Action Required

Parts Stock

Rework all 1250061 Wheel Assemblies from dealer Parts Stock. Dealers may either rework (if approved by the factory) the wheel assemblies as described in the attached procedure or return them as per Warranty Bulletin instructions.

Affected Product

Refer to the following options and see the attached procedure.

Option #1:

NOTE: Dealers will need to contact and provide information to Product Support at factory to insure the proper procedures are followed before being authorized to rework fabricated wheels.

Only Approved Dealers can replace wrapper bands. Replace the wrapper sections for each wheel assembly by following the attached procedure.

Option #2:

Replace Wheel Assembly with OR4171 Wheel Assembly from REMAN.

NOTE: Dealer must note on CCR (Core Credit Request) the wheel assembly is damaged, reference the PS5564 and warranty claim number. All the necessary paperwork should be filled out according to Caterpillar Core Acceptance Guidelines, Form No. SELD0072.

Option #3:

Replace wheel group with REMAN OR9040 Wheel Group. A maximum credit of $5,000.00 US will be allowed for the complete REMAN wheel group if this option is used.

NOTE: Dealer must note on CCR (Core Credit Request) the wheel assembly is damaged, reference the PS5564 and warranty claim number. All the necessary paperwork should be filled out according to Caterpillar Core Acceptance Guidelines, Form No. SELD0072.

Option #4:

Replace fabricated wheel group with REMAN cast wheel group Ref. part number OR9043.

NOTE: A maximum credit of $5,000.00 US will be allowed for the complete REMAN wheel group if this option is used. There is a one time upgrade charged when replacing a fabricated wheel group with a cast wheel group.

Reference IRM REM98-14 or form # PELE0608 dated May 1998.

Option #5:

Replace fabricated wheel assembly with a cast wheel assembly part number 142-5946 from the parts system. Reference service mag. dated August 24, 1998 for associated parts list.

NOTE: maximum credit of $5,000.00 US will be allowed for the cast wheel assembly.

NOTE: Dealer must note on CCR (Core Credit Request) the wheel assembly is damaged, reference the PS5564 and warranty claim number. All the necessary paperwork should be filled out according to Caterpillar Core Acceptance Guidelines, Form No. SELD0072.

Service Claim Allowances

Parts Stock

Submit one claim for all 1250061 Wheel Assemblies that were reworked in dealer Parts Stock or removed and returned to Reman.

Rework Parts Stock

Rework Options

NOTE: This is a 26-hour job to disassemble and assemble each wheel assembly.

NOTE: A maximum of $5,000.00 US will be allowed for replacing the wrapper sections for each wheel assembly.

NOTE: Dealers will need to contact and provide information to Product Support at factory to insure the proper procedures are followed before being authorized to rework fabricated wheels.

NOTE: This is a 26-hour job to disassemble and assemble each wheel assembly.

NOTE: Dealer must note on CCR (Core Credit Request) the wheel assembly is damaged, reference the PS5564 and warranty claim number. All the necessary paperwork must be filled out according to Caterpillar Core Acceptance Guidelines, Form No. SELD0072.

NOTE: This is a 12-hour job to remove and install each wheel assembly.

NOTE: A maximum credit of $5,000.00 US will be allowed for the complete REMAN wheel group if this option is used.

NOTE: Dealer must note on CCR (Core Credit Request) the wheel assembly is damaged, reference the PS5564 and warranty claim number. All the necessary paperwork should be filled out according to Caterpillar Core Acceptance Guidelines, Form No. SELD0072.

NOTE: This is a 12-hour job to remove and install each wheel assembly.

NOTE: A maximum credit of $5,000.00 US will be allowed for the complete REMAN wheel group if this option is used. There is a one time upgrade charged when replacing a fabricated wheel group with a cast wheel group. Reference IRM REM98-14 or form # PELE0608 dated May 1998.

NOTE: This is a 26-hour job to disassemble and assemble each wheel assembly.

NOTE: A maximum credit of $5,000.00 US will be allowed for the cast wheel assembly.

NOTE: Dealer must note on CCR (Core Credit Request) the wheel assembly is damaged, reference the PS5564 and warranty claim number. All the necessary paperwork should be filled out according to Caterpillar Core Acceptance Guidelines, Form No. SELD0072.

Parts Disposition

NOTE: Except for Option #1 ALL other options the fabricated rear wheel must be return to REMAN for core credit.

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

Attach.

(1-Rework Procedure)

Rework Procedure
Caterpillar Inc. Field Retrofit Welding Procedure

The following procedure is written to cover the retrofit of the hub casting-to-wrapper plates in the 1250061/">125-0061 wheel assembly. This weld procedure consists of removing the old wrapper plates, welding of new wrapper plates, and inspection.

PROCEDURE

Clean the wheel assembly of oil, grease, paint, and dirt. Welding operator personal protection should be provided to assure that total weld fume in the operators breathing zone is 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 welding the wheel assembly. 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 alternate process for this welding could be FCAW (Flux Cored Arc Welding).

A preheat and interpass temperature of 300 degrees and not exceeding 400 degrees Fahrenheit shall be maintained through out the repair. The preheat shall also be maintained 2" on either side of the weld.

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 50mm (2 inches)

27 J (20 ft lbs) Notch Toughness at -29 degrees C (-20 F)

These are low hydrogen electrodes and must be stored in an electrode oven at 250 degrees F when not in use. The electrodes may only be reheated once. 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 manufacturers 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 50mm (2 inches)

27 J (20 ft lbs) Notch Toughness at -18 degrees C (0 F)

Welding parameters will vary due to weld position and manufacturer of the welding electrode. For 1.3mm (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 wheel assembly. 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.

Begin the retrofit by machining out the original 12mm or the 16mm wrapper plates (125-0065 & 125-0066) and the (2) 125-0067 back-up strips. Next the weld joint needs to be machined to accommodate the new 16mm wrapper plates and back-up strips. After the weld joint is machined, it shall be cleaned. Tack the two (2) new back-up strips (169-0507) and wrapper plates (169-0505 & 169-0506) into place with a minimum root opening of 5mm as shown in Figure 1.

Weld the joint using extreme care on the root passes to ensure complete penetration. 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" E7018, the weld metal should be two times the electrode diameter. If the alternate welding process is selected, the welding pass size should not exceed (0.31") fillet volume.

Figure 1.

Illustration of the original hub casting-to-wrapper plate joint design

INSPECTION

The weld shall be inspected with ultrasonic testing (UT). The weld shall be free from cracks, porosity, undercut, and incomplete fusion. All weld quality shall conform to AWS D14.3 or Caterpillar Specification 1E99. Grind, blend, and paint as needed.

Bearing bores must be checked for size and location. Ref. SEHS9364 "Off Highway Truck Rear Wheel Salvage" or Illustration 3 after welding is complete.

Illustration 2

Illustration 3