CAMPAIGN: TIE ROD FRACTURE 1991 C3500 HD CHASSIS CAB

Subject: PRODUCT SAFETY CAMPAIGN 91C30 - TIE ROD FRACTURE

Model and Year: 1991 C3500 HD CHASSIS CAB TRUCKS

To: All Chevrolet Dealers

The National Traffic and Motor Vehicle Safety Act, as amended, provides that each vehicle which is subject to a recall campaign of this type must be adequately repaired within a reasonable time after the owner has tendered it for repair. A failure to repair within sixty (60) days after tender of a vehicle is prima facie evidence of failure to repair within a reasonable time.

If the condition is not adequately repaired within a reasonable time, the owner may be entitled to an identical or reasonably equivalent vehicle at no charge or to a refund of the purchase price less a reasonable allowance for depreciation.

To avoid having to provide these burdensome solutions, every effort must be made to promptly schedule an appointment with each owner and to repair their vehicle as soon as possible. As you will see in reading the attached copy of the letter that is being sent to owners, the owners are being instructed to contact the Chevrolet Customer Assistance Center if their dealer does not remedy the condition within five (5) days of the mutually agreed upon service date. If the condition is not remedied within a reasonable time, they are instructed on how to contact the National Highway Traffic Safety Administration.

DEFECT INVOLVED

General Motors has determined that a defect which relates to motor vehicle safety exists in 1991 C3500 HD Chassis Cab Trucks with a GVW (Gross Vehicles Weight) of 15, 000 lbs. These vehicles may exhibit a fatigue fracture of the tie rod through the damper stud mounting hole. If a fracture occurs, the vehicle would pull to the left during braking or when driving on a rough road and could result in a vehicle crash without prior warning.

To prevent this condition from occurring, dealers are to replace the existing tie rod assembly, damper and damper bracket with newly designed parts. The existing drag link will be reused.

VEHICLES INVOLVED

Involved are 1991 C3500 HD Chassis Cab Trucks with a GVW of 15,000 lbs. built within the following VIN breakpoints:

PLANT YEAR MODEL PLANT CODE FROM THROUGH ---- ----- ----- ----- ---- ------- 1991 C3500 HD Janesville "J" MJ100009 MJ112308

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 involved dealers with the campaign bulletin. Owner name and address data furnished will enable dealers to follow-up with owners involved in this campaign.

These 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.

OWNER NOTIFICATION

owners will be notified of this campaign on their vehicles by Chevrolet Motor Division (see copy of owner letter included with this bulletin).

DEALER CAMPAIGN RESPONSIBILITY

All unsold new vehicles in dealers' possession and subject to this campaign must be held and inspected/repaired per the service procedure of this campaign bulletin before owners take possession of these vehicles.

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.

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

In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.

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).

Quantity/ Part Number Description Vehicle ----------- ----------- --------- 15696702 Front Axle Mounting Bracket 1

15659623 Bolt - M10 - 1.5 x 30.0 1

11509775 Bolt - M14 - 2.0 x 50.0 1

15531206 Washer - M14 1

11500748 Lock Nut - M14 - 2.0 1

26035161 Tie Rod Assembly 1 (Includes Three (3) 5/8-18 Castle Nuts and Three (3) 1/8 X 1 1/2 Cotter Pins)

22064604 Steering Linkage Absorber 1

11509142 Bolt - M10 - 1.5 x 65.0 2

11501033 Lock Nut - M10 - 1.5 2

15614758 Hardened Washer - M10 1

SPECIAL TOOL

Special Tool J-39605 (Special 15mm Drill Bit) must be obtained from Kent-Moore tools by calling 1-800-345-2233. The Special Tool will be provided to dealers at no charge. When used properly, each drill bit should drill 3-5 axles.

NOTICE: THIS SPECIAL TOOL SHOULD ONLY BE ORDERED BY DEALERS WHO RECEIVE AN INVOLVED VEHICLE LISTING FOR THIS CAMPAIGN.

SERVICE PROCEDURE

Tools Required: 15mm Drill Bit (Special Tool) J-39605 Tie Rod Puller J-6627A Universal Steering Linkage Puller J-29107

1. Block rear wheels.

2. Lift front axle and support with jack stands.

3. Remove front tire and wheel assemblies (retain lug nuts).

4. Remove bolt (Figure 1, "2"), cotter pin (Figure 1, "5"), two (2) nuts (Figure 1, "3" and "4"), and steering linkage absorber (Figure 1, "1") which is attached to front axle mounting bracket. These parts will not be reused.

5. ON DRIVER'S SIDE ONLY: Remove and retain U-bolt (Figure 1, View B, "9"), nuts (Figure 1, View B, "C") and washers (Figure 1, View B, "B") which secure front stabilizer bar to front axle mounting bracket.

6. Remove remaining nut (Figure 1, View B, "10"), washer (Figure 1, View B, "9") and bolts (Figure 1, View B, "7" & 11811) which mount front axle mounting bracket (Figure 1, View B, "11") to front axle then remove front axle bracket. These parts will not be reused.

7. Enlarge forward hole in axle bean (used for front axle mounting bracket) using Special Tool J-39605 (15mm drill).

NOTICE: Hole being enlarged is the through hole on front axle which is closest to front bumper and through which bolt "3" in Figure 2 passes. Care should be taken to keep new hole aligned with old hole.

HOLE MUST BE DRILLED FROM BOTTOM OF AXLE UP USING SPECIAL TOOL DRILL BIT, J-39605. THIS DRILL BIT IS REQUIRED DUE TO INTERFERENCE WITH BOTTOM FLANGE OF FRONT AXLE. When used properly, each special tool drill bit should drill 3-5 axles.

8. Install replacement front axle mounting bracket (Figure 2, View B, "1") using new M10 bolt (Figure 2, View B, "2"), torque to 60-75 Nm (44-55 lb. ft.). Also, install new M14 bolt (Figure 2, View B, "3"), M14 washer (Figure 2, View B, "4") and M14 lock nut (Figure 2, View B, "5") torque to 120-130 Nm (89-96 lb ft.). M14 bolt must be installed in direction shown in Figure 2, View B.

9. Reinstall U-bolt, nuts and washers retained in step 5, and torque to 24-32 Nm (18-24 lb. ft.).

10. Remove cotter pin (Figure 1, "15") and castle nut (Figure 1, "14") which retain drag link to tie rod assembly. Cotter pin and castle nut will May be reused.

11. Using tie rod puller (J-6627A) or universal steering linkage puller (J-29107), disconnect drag link from tie rod assembly. Drag link will be reused in step 15.

NOTICE: Joint seal will be damaged if proper tool is not used.

12. Remove cotter pins (Figure 1, "13") and castle nuts (Figure 1, "12") retaining tie rod assembly to right and left spindles. Cotter pins and castle nuts will not be reused.

SERVICE PROCEDURE

13. Using tie rod puller (J-6627A) or universal linkage puller (J-29107) disconnect tie rod assembly (Figure 1, "6") from right and left spindles. Tie rod assembly will not be reused.

14. Install new tie rod assembly (Figure 2, "6") to right and left spindles using now 5/8-18 castle nuts (Figure 2, "7") and torque to 75-100 Nm (55-74 lb. ft.) . Retain castle nuts to right and left spindle locations using two new 1/8" x 1 1/2" cotter pins (Figure 2, "8").

15. Connect drag link to now tie rod assembly (Figure 2, "6") using new 5/8-18 castle nuts (Figure 2, "14") and torque to 95-115 Nm (70-85 lb. ft.). Retain castle nut with new 1/8" x 1 1/2" cotter pins (Figure 2, "15")

16. Install new steering linkage absorber (Figure 2, View A, "9") to new tie rod assembly (Figure 2, View A, "6") using new M10 bolt, M10 lock nut and M10 washer (Figure 2, View A, "10", "11" and "12"). Torque to 40-50 Nm (30-37 lb. ft.).

NOTICE: Bolt must be installed in direction shown in Figure 2, View A.

17. Install new steering linkage absorber to new front axle mounting bracket (Figure 2, "1") using a new M10 bolt (Figure 2, "10") and M10 lock nut (Figure 2, "11"). Torque to 40-50 Nm (30-37 lb. ft.).

18. Retrieve retained lug nuts and reattach front tire and wheel assemblies. Torque lug nuts to 240 Nm (177 lb. ft.).

19. Perform complete toe-in adjustment. Steering wheel must be locked and centered. Toe-in should be set to the following specifications:

Service Checking Service Setting ---------------- --------------- Sum Toe-in: 0.06 0.06 in. 0.06 0.06 in. 1.52 1.52 mm. 1.52 1.52 mm. 0.12 0.12 degrees 0.12 0.12 degrees

NOTICE: This is a new tie rod system.

20. Align right front wheel (Passenger Side) by using drag link adjuster tube assembly and the following procedure:

a. Position drag link adjuster clamps on adjuster tube so edge of clamp ears do not fall on adjuster tube slot (Figure 3, View A).

b. Adjuster clamps must be located BETWEEN (not ON) stamped adjuster tube dimples.

c. Ears of drag adjuster tube clamps must be rotationally positioned as specified in Figure 3, View A.

d. Tighten drag link adjuster clamp nuts to 68 NM (50 lb. ft.).

e. Drag link assembly must be capable of rocking on socket pivots through a minimum of eight (8) degrees total after clamps are tightened.

NOTICE: If tools are used to rotate adjuster tube, special attention must be given to prevent damage to corrosion protection coating.

21. Align left front wheel (Drivers Side) by using tie rod adjuster tube assembly and the following procedure:

a. Position tie rod adjuster clamps on adjuster tube so edge of clamp ears do not fall on adjuster tube slot (Figure 3, View A).

b. Adjuster clamps must be located BETWEEN (not ON) stamped adjuster tube dimples.

c. Ears of tie rod adjuster tube clamps must be rotationally positioned as specified in Figure 3, View A.

d. Tighten tie rod adjuster clamp nuts to 68 Nm (50 lb. ft.).

NOTICE: If tools are used to rotate adjuster tube, special attention must be given to prevent damage to corrosion protection coating.

22. Remove axle supports, lower front axle and remove rear wheel blocks.

23. Install "Campaign Identification Label".

CAMPAIGN IDENTIFICATION LABEL

Each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin will require a "Campaign Identification Label". Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen.

Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner. Additional "Campaign Identification Labels" can be obtained from DAC.

Apply "Campaign Identification Label" only on a clean, dry surface.

CLAIM INFORMATION

Submit a Product Campaign Claim with the information indicated below:

FAILED PARTS CC-FC LABOR LAB OTH REPAIR PERFORMED PC PART NO. ALLOW 0P HRS HRS ---------------- -- -------- ----- ----- ----- --- --- Replace Tie Rod 12 26035161 ** SK-00 V7390 1.6 0.1 Assemblies

* Campaign Administrative Allowance.

** The "Parts Allowance" should be the sum total of the current GMSPO Dealer Net price plus 30% of all parts required for the repair.

Dealers will automatically receive the correct labor and material allowance based on the labor operation performed.

Refer to the Chevrolet Claims Processing Manual for details on Product Campaign Claim Submission.

Dear Chevrolet C3500 HD Chassis Cab Truck owner:

This notice is sent to you in accordance with the requirements of the National Traffic and Motor Vehicle Safety Act.

REASON FOR THIS RECALL

General Motors has determined that a defect which relates to motor vehicle safety exists in 1991 C3500 HD Chassis Cab Trucks with a GVW (Gross Vehicles Weight) of 15,000 lbs. These vehicles may exhibit a fatigue fracture of the tie rod through the damper stud mounting hole. If a fracture occurs, the vehicle would pull to the left during braking or when driving on a rough road and could result in a vehicle crash without prior warning.

WHAT WE WILL DO

To prevent the possibility of this condition occurring, your dealer will replace the existing tie rod assembly, damper and damper bracket with newly designed parts. The existing drag link will be reused. This service will be performed for you at no charge.

WHAT YOU SHOULD DO

Please contact your Chevrolet dealer as soon as possible to arrange a service date and so the dealer may order the necessary parts for the repair. Instructions for making this correction have been sent to your dealer and parts are available. The labor time necessary to perform this service correction is approximately one hour and thirty minutes to two hours. Please ask your dealer if you wish to know how much additional time will be needed to schedule and process your vehicle.

Your Chevrolet dealer is best equipped to obtain parts and provide service to ensure that your vehicle is corrected as promptly as possible. If, however, you take your vehicle to your dealer on the agreed service date, and they do not remedy this condition on that date or within five (5) days, we recommend you contact the Chevrolet Customer Assistance Center by calling 1-800-222-1020.

After contacting your dealer and the Customer Assistance Center, if you are still not satisfied that we have done our best to remedy this condition without charge and within a reasonable time, you may wish to write the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, S.W., Washington, D.C. 20590 or call 1-800-424-9393 (Washington D.C. residents use 366-0123).

The enclosed owner reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction in the shortest possible time. If you have sold or traded your vehicle, please let us know by completing the postage paid reply card and returning it to us.

We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your safety and 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.