Service Procedures
INITIAL POSITIONING OF REINFORCEMENT1. Raise front of vehicle and support it with suitable safety stands.
2. Clean left and right lower control arms of dirt, rust, grease and undercoating from the spring pocket outboard to the flange surrounding the ball joint. Clean both top and bottom areas of control arms. This will insure good mechanical contact of the reinforcement and U-bolt to the control arm and ball joint flange. Use appropriate solvents and/or a wire brush as required. If control arms and reinforcement are not thoroughly cleaned, the U-bolt may "walk off" the bottom of the ball joint when it is tightened.
3. Center reinforcement between flanges (Figure 1). The technician may want to do one side at a time. Gaps A & B (Figure 1) are to be equal to within 0.060 inch (1.5 mm) Secure reinforcement with a "C" clamp (Figure 2).
NOTICE:
Reinforcement is installed CORRECTLY when ball joint makes full contact with reinforcement radius (Figure 1, Item 2) not just in center section of reinforcement.
Reinforcement is designed to fit ball joints with a bottom diameter of 2.60 inches (66 mm) or greater. Technician may find that ball joint does not make full contact with radius of reinforcement when reinforcement is centered correctly between flanges.
It may be possible that an after market ball joint with a bottom diameter which is less than 2.60 inches (66 mm) has been installed. This does not allow for full contact with the radius of the reinforcement. When this condition happens, only a small section of the ball joint will come in contact with the reinforcement. If this occurs, make certain ball joint is clean as described in step 1 and measure bottom diameter of ball joint with a caliper. If measurement is LESS THAN 2.60 INCHES (66 MM) the ball joint must be replaced with a GM ball joint.
If an after market lower control arm has been installed, it will be necessary to remove the aftermarket control arm, install a GM designed control arm and perform the installation of the reinforcement per the campaign service procedure.
4. Install U-bolt (Figures 1 & 3) and torque nuts to approximately 10 Nm (7 lb.ft.).
IMPORTANT:
This step must be performed before proceeding to step 5.
NOTICE:
When correctly installed, U-bolt will be about even with bottom of ball joint. U-bolt is NOT designed to fit into galley of control arm. On some vehicles, U-bolt may contact flange edge of control arm and interfere with correct installation. If this happens, locate and mark area where U-bolt comes in contact with control arm. You may remove only enough material (LIGHTLY grind) (Figure 2A) from OUTER radius of U-bolt to allow clearance between U-bolt and control arm (Figure 2, Item 7).
5. Drill a center hole with a 3/8 inch (9.5 mm) drill. Reinforcement has been designed to be used as a template. When drilling keep drill as perpendicular as possible.
6. Install a 3/8-16 bolt (Figure 2, Item 6), nut (Figure 2, Item 3) and washer (Figure 2, Item 2) in center hole and torque to approximately 18 N-m (13 lb.ft.).
7. Remove "C" Clamp.
8. Drill remaining holes in sequence.
9. Disassemble reinforcement (Figure 2, Item 1) and U-bolt (Figure 2, Item 7) from control arm and remove all chips and burs from lower control arm and reinforcement.
INSTALLATION OF REINFORCEMENT
1. Reinstall reinforcement (Figure 3, Item 1) and U-bolt (Figure 3, item 7). Hand start all bolts and nuts. Tighten U-bolt nuts (Figure 3, Item 5) to approximately 22 N-m (16 lb.ft.). Make sure U-bolt is ALIGNED with bottom edge of ball joint and is not cocked while continuing to torque.
NOTICE:
If rear most bolt head interferes with bump stop bracket, install bolt from bottom of control arm.
2. Torque 3/8-16 bolts (Figure 3) to 37-43 N-m (27-32 lb.ft.) Torque center bolt first and remainder in any sequence.
3. Torque U-bolt nuts (Figure 3) to 40-46 N-m (30-34 lb.ft.).
4. Continue to other side of vehicle and follow steps 1-3 above for that lower control arm.
5. Once both lower control arm reinforcements have been installed and torqued, lower vehicle.
6. Install Campaign Identification Label.