See Figures 1 through 12
Instead of springs, the 1990-91 4WD Vista uses transversely mounted torsion bars housed inside the rear crossmember, attached to which are inner and outer control arms. Conventional style shock absorbers are mounted on the inner arms.
REMOVAL & INSTALLATION
- Raise and support the car with jackstands under the frame.
- Remove the differential.
- Remove the intermediate shafts and axleshafts.
- Remove the rear brake assemblies.
- Disconnect the brake lines and parking brake cables from the inner arms.
- Remove the main muffler.
- Raise the inner arms slightly with a floor jack and disconnect the shock absorbers.
- Matchmark, precisely, the upper ends of the outer arms, the torsion bar ends and the top of the crossmember bracket and remove the inner and outer arm attaching bolts.
- Remove the extension rods fixtures attaching bolts.
- Remove the crossmember attaching bolts and remove the rear suspension assembly from the car.
- Unbolt and remove the damper from the crossmember.
- Remove the front and rear insulators from both ends of the crossmember.
- Loosen, but do not remove, the lockbolts securing the outer arm bushings at both ends of the crossmember.
- Pull the outer arm from the crossmember. Many times, the torsion bar will slide out of the crossmember with the outer arm.
- Remove the torsion bar from either the crossmember or outer arm.
- Inspect all parts for wear or damage. Inspect the crossmember for bending or deformation.
- Inner arm bushings may be replaced at this time using a press. The thicker end of the bushings goes on the inner side.
- Prior to installation note that the torsion bars are marked with an L or R on the outer end, and are not interchangeable.
- If the original torsion bars are being installed, align the identification marks on the torsion bar end, crossmember and outer arm, install the torsion bar and arm and tighten the lockbolts. Skip Step 20. If new torsion bars are being installed, proceed to Step 20.
- A special alignment jig must be fabricated. See the accompanying illustration for the dimension needed to make this jig. The jig is bolted to the rear insulator hole on the crossmember bracket as shown. Install the crossmember bracket as shown. Install the crossmember and inner arms. Insert the torsion bar into the outer arm, aligning the red identification mark on the torsion bar end with the matchmark made on the outer arm top side. Install the torsion bar and arm so that the center of the flanged bolt hole on the arm is 32mm below the lower marking line on the jig. Then, pull the outer arm off of the torsion bar, leaving the bar undisturbed in the crossmember. Reposition the arm on the torsion bar, one serration counterclockwise from its former position. This will make the previously measured dimension, 33mm above the lower line. In any event, when the outer arm and torsion bar are properly positioned, the marking lines on the jig will run diagonally across the center of the toe-in adjustment hole as shown. When the adjustment is complete, tighten the lockbolts. The clearance between the outer arm and the crossmember bracket, at the torsion bar, should be 5.0-7.0 mm.
Complete the remainder of the component parts installation. Observe the following torques:
Extension Rod Fixture bolts: 45-50 ft. lbs.
- Lower the car to the ground and check the ride height. The ride height is checked on both sides and is determined by measuring the distance between the center line of the toe-in bolt hole on the outer arm, and the lower edge of the rebound bumper. The distance on each side should be 102-104mm. If not, or if there is a significant difference between sides, the torsion bar(s) positioning is wrong.