CAMPAIGN:REAR LOWER CONTROL ARM BALL JOINT STUD TO KNUCKLE

TO: ALL GENERAL MOTORS DEALERS

General Motors has determined that a defect which relates to motor vehicle safety exists in some 1986 Oldsmobile Delta 88 Models. The left and right rear lower control arm ball joint stud to knuckle attachment may have been inadequately tightened when these vehicles were assembled. This could allow the rear lower control arm ball joint stud to loosen at the knuckle attachment. A loose ball joint stud could eventually break and separate from the knuckle. Separation could cause a loss of vehicle control which could result in a vehicle crash without prior warning.

To prevent the possibility of this occurring on vehicles involved, Dealers are to replace and tighten the left and right rear lower control arm ball joint stud nut and, if necessary, replace the knuckle(s) as outlined in the Service Procedure section of this bulletin.

VEHICLES INVOLVED:

Involved are all 1986 Oldsmobile Delta 88 Models within the following serial numbers:

Assembly Plant Beginning Up To And Including -------------- --------- -------------------

Willow Run (W) Start of Production GW341352

All affected vehicles have been identified by the VIN listing provided to involved Dealers with this bulletin. Any Dealer not receiving a listing was not shipped any of the affected vehicles.

Dealer Campaign Responsibility

Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward.

Whenever a vehicle subject to this Campaign is taken into your new or used vehicle inventory, or it is in your Dealership for service in the future, you should take the steps necessary to be sure the campaign correction has been made before reselling 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.

CAMPAIGN PROCEDURE:

Refer to Section 4 of the Service Policies and Procedures Manual for the detailed procedure on handling Product Campaigns. Dealers are requested to complete the campaign on all transfers as soon as possible.

OWNER NOTIFICATION:

All owners of record at the time of campaign release are shown on the attached computer listing and have been notified by first class mail from General Motors. The listings provided are for campaign activity only and should not be used for any other purpose.

PARTS INFORMATION:

Parts required for this modification should be ordered through regular channels as follows:

PART NUMBER QUANTITY DESCRIPTION USAGE

11504131 *2 Castellated Nut Rear Lower Control Arm Ball Joint Stud Outer Suspension Adjustment Link 11509456 *2 Cotter Pin Rear Lower Control Arm Ball Joint Stud Outer Suspension Adjustment Link 25522880 1 Knuckle R.H. ---- (If Req'd.) 25522881 1 Knuckle R.H. ---- (If Req'd.)

*Quantity of 3 if a knuckle is replaced.

PARTS AND LABOUR CLAIM INFORMATION:

Credit for the campaign work performed will be paid upon receipt of a properly completed campaign claim card or RAPID terminal transmission in accordance with the following:

Repair Code Operation Time Allowance

2A Inspect both sides. Replace 1.1 ball joint stud nuts and Cotter pins.

3A Inspect both sides. Replace 2.1 one side ball joint stud nut and Cotter Pin. Replace one side knuckle, ball joint stud nut, cotter pin, outer suspension adjustment link nut, and cotter pin. Align rear suspension.

4A Inspect both sides. Replace both knuckles, ball joint stud 3.0 nuts, and cotter pins. Replace both outer suspension adjustment link nuts and cotter pins. Align rear suspension.

Time allowance includes 0.1 hour for Dealer administrative detail associated with this campaign. Parts credit will be based on Dealer net plus 30% to cover parts handling.

SERVICE PROCEDURE:

A. Inspection ----------

1. Using a frame contact hoist, lift vehicle so suspension hangs free.

2. Remove both rear tire and wheel assemblies.

3. Remove the cotter pin from the left and right rear lower control arm ball joints. Refer to Figure 1.

4. Slowly loosen each castellated ball joint nut (2) two turns and determine if the ball joint moves downward and begins to separate from the knuckle.

5. Determine which of the following conditions exist at either or both of the ball joints.

- Ball joint does not move downward and does not begin to separate from the knuckle when castellated nut is loosened. Proceed to Part B of this service procedure.

- Ball joint moves downward and begins to separate from the knuckle when the castellated nut is loosened. Proceed to Part C of this service procedure.

B. Ball joint does not move downward and does not begin to separate from the knuckle when the cast castellated nut is loosened:

1. Place a suitable jack under the control arm and remove coil spring tension from the ball joint.

Note: The control arm must be supported to prevent the coil spring from forcing the control arm downward.

2. Remove the castellated nut from the rear lower control arm ball joint. Turn nut over and reinstall with flat side of nut facing upward. Do not tighten nut.

3. Install tool J34505. Refer to Figure 2. Tool J34505 was included with 1984-85 essential tools.

4. Separate knuckle from ball joint stud by backing off inverted nut against tool J34505.

5. Remove tool J34505 and castellated nut.

6. Install new castellated nut, part number 11504131 flat side down.

7. Tighten new nut to 10 N.m (7 lbs. ft.).

8. Tighten nut an additional 2/3 turn. A minimum torque of 55 N.m (41 lbs. ft.) must have been achieved by this time.

Note: It may be necessary to partially load joint to keep ball joint from rotating while nut is being tightened.

If a minimum of 55 N.m (41 lbs. ft.) has not been obtained, proceed to Part C of this service procedure.

9. Align slot in castellated nut to cotter pin hole in ball joint stud by tightening only. DO NOT loosen nut to align for cotter pin installation.

10. Install new cotter pin.

11. Install tire and wheel assembly.

12. Install campaign identification label.

C. Ball joint moves downward and begins to separate from the knuckle when the castellated nut is loosened:

1. Place a suitable jack under the control arm and remove coil spring tension from the ball Joint.

Note: The control arm must be coil spring from forcing supported to prevent the coil spring from forcing the control arm downward.

2. Remove cotter pin and nut from outer suspension adjustment link. Refer to Figure 3.

3. Remove brake line bracket from backing plate.

4. Separate outer suspension adjustment link from knuckle using tool J24319-01 or equivalent. Refer to Figure 3.

5. Remove the castellated nut from the rear lower control arm ball joint.

6. Separate knuckle from rear lower control arm ball joint.

7. Remove brake drum.

8. Remove four (4) hub and bearing assembly to knuckle bolts. When removing these bolts, support the brake assembly with a wire or other means. Do not let the brake line support the brake assembly.

9. Install new knuckle, install strut to knuckle bolts, and tighten to 195 N.m (144 lbs. ft.).

10. Install four (4) hub and bearing assembly to knuckle bolts,and tighten to 70 N.m (52 lbs. ft.).

11. Install outer suspension adjustment link to knuckle using new nut, part number 11504131 and tighten to 50 N.m (37 lbs. ft.). After tightening, align cotter pin slot by tightening nut only. DO NOT loosen nut to align for cotter pin installation.

12. Install new cotter pin.

13. Install brake line bracket to backing plate. Tighten bolts to 10 N.m (7 lbs. ft.).

14. Install new castellated nut, part number 11504131 on rear lower control arm ball joint stud.

15. Tighten new nut to 10 N.m (7 lbs. ft.).

16. Tighten nut an additional 2/3 turn to achieve a minimum torque of 55 N.m (41 lbs. ft.).

Note: It may be necessary to partially load joint to keep ball joint from rotating while nut is being tightened.

17. Align slot in castellated nut to cotter pin hole in ball joint stud by tightening only. DO NOT loosen nut to align for cotter pin installation.

18. Install new cotter pin.

19. Install tire and wheel assembly.

20. Align rear suspension. Refer to section 3A in the 1986 Firenza, Calais, Cutlass Ciera, Delta 88 and Ninety-Eight Chassis Service manual.

21. Install campaign identification label.

INSTALLATION OF CAMPAIGN IDENTIFICATION LABEL

Clean surface of radiator upper mounting panel and apply a Campaign Identification Label. Make sure the correct campaign number is inserted on the label. This will indicate that the campaign has been completed.

Dear General Motors Customer:

This notice is seat to you in, accordance with the requirements of the Canada Motor Vehicle Safety Act.

General Motors of Canada has determined that a defect which relates to motor vehicle safety exists in some 1986 Oldsmobile Delta 88 models. The left and right rear lower control arm ball joint stud to knuckle attachment may have been inadequately tightened when these vehicles were assembled. This could allow the rear lower control arm ball joint stud to loosen at the knuckle attachment. A loose ball joint stud could eventually break and separate from the knuckle. Separation could cause a loss of vehicle control which could result in a vehicle crash without prior warning.

To prevent this from occurring on your vehicle, please contact your GM Dealer to arrange a service date. The Dealer will replace and tighten both left and right rear lower control arm ball joint stud nuts and, if necessary, replace the knuckle(s). This service will be completed for your at no charge.

Instructions have been sent to your GM Dealer. The labour time to replace and tighten both left and right rear lower control arm ball joint studs is approximately one hour. If knuckle replacement is necessary, additional labour time of approximately one hour each will be required.

This letter identifies your vehicle. Presentation of this letter to your Dealer will assist their Service personnel in completing the necessary correction to your vehicle in the shortest possible time.

Further assistance, if required, may be obtained from the General Motors Zone Office nearest you. Your vehicle Owner's ;Manual provides the location and phone number of each respective Zone Office.

We are sorry to cause you this inconvenience; however, we have taken the 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.