4472 TRANSFER CASE DIAGNOSIS AND EXCHANGE PROCEDURE

SUBJECT: BORG-WARNER 4472 TRANSFER CASE DIAGNOSIS AND EXCHANGE PROCEDURE

MODEL and YEAR: 1990-93 L VANS (ALL WHEEL DRIVE ASTRO VAN)

THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-279-7D, DATED SEPT. 1992. THE 1993 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 92-279-7D SHOULD BE DISCARDED.

This bulletin covers the preliminary diagnosis and exchange procedure for the Borg-Warner 4472 transfer case. The exchange program is to provide useful feedback for continuous improvement of the 4472 transfer ease. Therefore,any 4472 transfer case needing warranty repair, other than output shaft seal replacement, is to be exchanged for a replacement unit.

IMPORTANT: In the event that the unit is repaired as a customer pay or other non-exchange arrangement, refer to the GMSPO Parts Catalog (Group 4) for a listing and an illustration of serviceable components for the 4472 transfer case.

SERVICE PROCEDURE:

Before replacing a Borg-Warner 4472 transfer case, follow the DIAGNOSTIC PROCEDURE below.

DIAGNOSTIC PROCEDURE:

1. Ensure correct oil fill.

2. Ensure all engine and transmission mounts are tight.

3. Check for proper tire inflation.

4. Refer to the Diagnostic Charts located in Section 7D in the appropriate service manual for a detailed diagnostic procedure.

IMPORTANT: Ensure front and rear propeller shafts are marked relative to other driveshaft components before disassembly. These components are match balanced and MUST be reassembled in the same relationship to maintain proper balance. Refer to Section 4A of the appropriate Service Manual for further information.

5. If the diagnosis indicates the need to replace the transfer case, the following EXCHANGE PROCEDURE should be followed.

EXCHANGE PROCEDURE:

1. Record the information listed in the Reporting Form (Figure 1). If the vehicle has an oil leak, determine where the leak is by using the oil leak identification chart (Figure 2). The noise chart in Figure 1 can be filled out by using check marks. It is necessary to record this information as it will be needed to fill out the form on the transfer case being returned. Blank forms will be shipped with the exchange unit. Record the GM part number, the Borg-Warner part number, and the unit serial number from the I.D. tag located at the rear of the transfer case.

2. With the information from Figures 1 and 2 available, call Chevrolet Technical Assistance Network (TAN). Technical Assistance will arrange with Borg-Warner Automotive to ship an exchange unit within one working day (24 hours). Replacement transfer cases will be shipped to the dealer on a no charge basis.

3. The dealership will be provided with an authorization number by Borg-Warner. This number MUST be written on the transfer case in black marker before its return. If the case is excessively greasy, write the authorization number on a tag and attach it to the case with wire.

4. Once an exchange unit is received, the replaced unit is to be returned to Borg-Warner Automotive within 10 days to avoid a chargeback. A return shipping label will be sent with the exchange unit.

5. The replaced unit MUST be returned complete as removed from the vehicle WITHOUT any disassembly of the unit. Dealerships returning units even partially disassembled will be subject to being billed for materials furnished.

6. The exchange unit will have a plastic bag attached to it. This bag will contain:

- Return shipping labels

- A reporting form

- Return shipping carrier information

- Identification tag

- Leak identification chart

PREPARATION FOR SHIPPING:

1. Drain all of the oil from the unit.

2. Remove all plastic shipping plugs and covers from the replacement unit and install them on the replaced unit.

3. Place the reporting form, the identification forms, and a copy of the repair order in the plastic bag. Attach the bag and the identification tag to the replaced unit with the enclosed wire.

4. Write the authorization number on the case cover of the replaced unit.

5. Repack the replaced unit into the original shipping container.

6. Place the shipping label on the original shipping container.

IMPORTANT: All return shipping is COD to Borg-Wamer.

WARRANTY INFORMATION:

For vehicles repaired under warranty, use:

Labor Operation Labor *Part Model Number Description Time Allowance ----- --------- ----------- ----- --------- L K4410 Transfer Case Asm - Replace 1.5 hrs. $101.78 T K4410 Transfer Case Asm - Replace 2.1 hrs. $101.78

*The amount identified in the "Part Allowance" column above represents 30 percent of dealer net for parts that were furnished by Borg-Warner. This amount is to be placed in the Net Amount column of the claim.

*0.1 hrs of administrative time has been added tot he above Labor Time for filling out the Reporting and Identification forms.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.