For 1990-2009 cars

# CAMPAIGN: FRONT DRIVE AXLE NUT REPLACEMENT

#### MODELS AFFECTED: 1989 RIVIERA AND REATTA

#### CONDITION

General Motors has determined that some 1989 Riviera and Reatta model vehicles may have been assembled with front drive axle nuts that may loosen slightly. If this occurs, the clamp load for the wheel bearing may decrease resulting in reduced bearing life or bearing failure.

#### DEALER ACTION

To prevent this condition from occurring, dealers will be required to replace both front drive axle nuts on all affected vehicles. In addition, on some vehicles, dealers are to inspect and replace, if necessary, affected wheel bearing assemblies. Specifics are detailed in the Vehicles Involved and Service Procedure sections of this bulletin.

#### VEHICLES INVOLVED

All 1989 Riviera and Reatta model vehicles within the following vehicle breakpoints:

Year Plant From Through and Including ---- ----- ---- ---------------------- Group 1: 1989 Hamtramck KU400001 KU401763 1989 Reatta Craft KB900001 KB901034 Centre

Group 2: 1989 Hamtramck KU401764 KU403487 1989 Reatta Craft KB901035 KB901911 Centre

Each Group has a separate service procedure.

#### OWNER NOTIFICATION

Owners of vehicles involved in this campaign will be notified by Buick Motor Division (see copy of owner letter included with this bulletin).

#### DEALER CAMPAIGN RESPONSIBILITY

Dealers are to service all vehicles involved in this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership. Whenever a vehicle subject to this campaign is taken into your new or used car inventory, dealers are to take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.

Owners of vehicles recently sold from your new vehicle inventory are to be contacted by the dealer and arrangements made to make the required modification according to instructions contained in this bulletin.

In addition, dealers are to perform the campaign on all affected vehicles as they are brought in for any kind of service.

#### DEALER MATERIAL

If your dealership has vehicles involved in this campaign, you will receive the following items:

- Listing of all vehicles involved in this campaign shipped to your dealership.

- One (1) Campaign Identification Label per vehicle involved.

Involved vehicles have been identified by Vehicle Identification Number computer listings. Computer listings contain the complete vehicle identification number, owner name and address data, and are furnished to the involved dealers with the campaign bulletin. Owner name and address data will enable dealers to follow-up with owners involved in this campaign.

These computer listings may contain owner names and addresses obtained from State Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned.

#### CHANGE OF OWNER INFORMATION

Dealers are to use the Dealer Communication System (DCS) to provide Buick Motor Division with subsequent Buick owner information. By reporting a change of owner name or address of a vehicle in campaign status over the DCS, the need to send a CVAR form for that vehicle is eliminated. Terminal input instructions are covered in the DCS Manual under Setion 9, Page 9-J01A and B.

#### PARTS INFORMATION

Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). To ensure these parts will be obtained as soon as possible, they should be ordered from GMSPO on a C.I.O. order, with NO special instruction code, but on an advise code (2).

#### NOTICE: Parts must be ordered according to VIN range. Be certain to check the VIN of the vehicle being serviced to obtain the correct parts. Refer to the Vehicles Involved section of this bulletin.

VIN Range Part Number Description Quantity --------- ----------- ----------- --------- Group 1 3634775 Service Kit* 1 7466961 Hub & Bearing Assy As Required** 14084119 Bearing Seal As Required** 22529144 Brake Caliper Bolt As Required (two per Hub and Bearing Assembly)

Group 2 14035592 Torque Prevailing Nut 2 10049691 Large Washer 2

* NOTICE: Each Service Kit contains 2 splined washer adapters, 2 washers, 2 torque prevailing nuts and 2 nut retainers for servicing both the left and right front drive axles.

**NOTICE: It is anticipated that less than 10% of the hub and bearing assemblies within the Group 1 VIN ranges will require replacement. Bearing assemblies are not included in the Service Kit and must be ordered separately. Please adjust your parts orders accordingly. Vehicles within the Group 2 VIN range should not require any wheel bearing assembly replacements.

#### SERVICE PROCEDURE (Applies to both left and right front drive axles)

Group 1 (Riviera KU400001-KU401763 and Reatta KB900001-KB901034)

1. Support front of vehicle. Lift vehicle enough to removal most of the weight of the vehicle from the ground, but keep the tires on the ground to prevent rotation during torque readings.

2. Remove front wheel covers or wheel inserts.

3. Loosen drive axle nut one-sixth turn (one flat).

4. Tighten nut to original position.

5. Check and record torque to re-loosen drive axle nut.

6. If torque in Step 5 is below 80 N.m (60 ft. lbs.) replace hub and bearing assembly and seal per 1989 Reatta Riviera Service Manual procedure, Pages 3C-6 through 8.

#### NOTICE: If a hub and bearing assembly is replaced, the two brake caliper bolts (part number 22529144) MUST also be replaced (see Notice on Page 5B3-1 of Service Manual).

7. Remove original drive axle nut and washer and discard.

#### NOTICE: For Steps 8 through 11 refer to Illustration #1 and use Service Kit Part Number 3634775.

8. Install splined washer adaptor.

9. Install new washer.

10. Install new torque prevailing nut and torque to 245 N.m (180 ft. lbs.).

#### IMPORTANT: Use torque wrench to tighten drive axle nut to specification.

11. Install nut retainer over nut and be certain that the three tabs latch into the three notches in the splined washer adaptor. If tabs and notches do not align, tighten nut further to align. Do not exceed 275 N.m (200 ft. lbs.)

12. Install front wheel cover or wheel insert.

13. Remove support from front of vehicle.

14. Install Campaign Identification Label.

Group 2 (Riviera KU401764-KU403487 and Reatta KB901035-KB901911)

1. Support front of vehicle. Lift vehicle enough to remove most of the weight of the vehicle from the ground, but keep the tires on the ground to prevent rotation during torque readings.

2. Remove front wheel covers or wheel inserts.

3. Remove drive axle nut and washer and discard.

#### NOTICE: For Steps 4 and 5, refer to Illustration #2.

4. Install new washer (part number 10049691).

5. Install new torque prevailing nut (part number 14035592) and torque to 245 N.m (180 ft. lbs.).

#### IMPORTANT: Use torque wrench to tighten drive axle nut to specification.

6. Install front wheel covers or wheel inserts.

7. Remove support from front of vehicle.

8. Install Campaign Identification Label.

#### CAMPAIGN IDENTIFICATION LABEL INSTALLATION

Each label provides a space to include the CAMPAIGN NUMBER, the five (5) digit dealer code of the dealer performing the campaign service, and the date vehicle was campaigned. This information may be inserted with a typewriter or ballpoint pen. When installing label, clean the surface of the radiator support tie bar and apply the campaign label where it is readily visible.

#### DISPOSITION OF PARTS

Replaced parts must be held for disposition by Buick Zone or Branch contact personnel. Parts must have a claim tag attached showing the repair order and the VIN of the vehicle from which they were removed.

#### WARRANTY INFORMATION

List the one applicable labor operation.

FAILED OTHER SUBLET PART PART PARTS FAILURE LABOR LABOR LABOR DEALER OPER COUNT NUMBER ALLOW CODE OP NO HOURS HOURS MTL TWG ---- ----- ------ ----- ---- ------ ----- ----- -------- Group 1 -------- o Install Service Kit Only 1 3634775 96 V5310 .6 *.l --

o Install Service Kit and One Bearing Assembly 5 3634775 96 V5311 1.0 *.l --

o Install Service Kit and Two Bearing Assemblies 9 3634775 96 V5313 1.5 *.l --

Group 2

o Install Washers and Nuts 4 14035592 96 V5312 .4 *.l --

* 0.1 hour administration.

** List current dealer price of all parts required for repair, plus 30%.

This notice is sent to you to notify you that your 1989 Buick is involved in a recall.

REASON FOR RECALL

General Motors has determined that your Buick Riviera or Reatta may have been assembled with front drive axle nuts that may loosen slightly. If this occurs, the clamp load for the wheel bearing may decrease. Although wheel retention and steering control will not be affected, this condition could lead to reduced bearing life resulting in noisy front wheel bearings.

WHAT WE WILL DO

To prevent this from occurring on your vehicle, your Buick dealer will replace both drive axle nuts and, if necessary, replace affected wheel bearing assemblies. This service will be performed at no charge to you.

WHAT YOU SHOULD DO

Please contact your Buick dealer to arrange a service date.

Instructions for making this correction have been sent to your Buick dealer. The labor time to replace both drive axle nuts is approximately 25 minutes. However, if one or both wheel bearing assemblies require replacement, an additional one hour may be necessary. Also, please allow additional time for your dealer to process your vehicle.

The enclosed Owner Reply Card identifies your vehicle. Presentation of this card to your dealer will assist in making the correction in the shortest possible time. If you have sold or traded your vehicle, please complete the postage-paid card and return it to us. This will assist us in assuring all affected vehicles have been corrected.

We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products.

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.