The rack piston converts hydraulic pressure to a linear force which moves the rack left or right. The force is then transmitted through the inner and outer tie rods (also called tie rod ends) to the steering knuckles, which turn the front wheels. The tie rod ends determine the front wheel alignment toe-angle, and they are adjustable.
REMOVAL & INSTALLATION
Tie Rod Ends
Normally, the only steering linkage components that may require service are the tie rod ends which connect the rack and pinion steering gear to the wheel knuckles.
- Raise and safely support the vehicle.
- The outer tie rod ends may be retained to the steering knuckle by either a slotted nut and cotter pin or a torque-prevailing nut. If a slotted nut and cotter pin is used, remove and discard the cotter pin and remove the slotted nut.
- If a torque prevailing nut is used, remove the nut from the tie rod end's ball stud at the wheel knuckle. GM specifies that this torque prevailing nut be discarded and a new torque prevailing nut be used at assembly. Most service replacement tie rod ends come with new hardware.
- The position of the tie rod ends determines the toe angle of the steering alignment. To get the replacement tie rod end positioned as closely as possible to the original tie rod end's position, the jam nut's position should be marked. Some technicians, after thoroughly wire-brushing the jam nut and the inner tie rod shaft threads, will mark one flat of the jam nut with paint. Then, the jam nut is loosened exactly one turn.
- Remove the tie rod end from the wheel knuckle. GM says that the tapered joint of the ball stud has been designed to separate easily, unlike previous joints of this type. If required, use a tie rod puller to separate the tie rod end from the wheel knuckle.
- Unscrew the tie rod end from the inner tie rod shaft. Do not disturb the jam nut. It should have been loosened one turn only from its original position.
- Clean all parts well. Make sure mating surfaces of the stud and knuckle are clean.
- Thread the replacement tie rod end onto the inner tie rod shaft until it just touches the jam nut. Loosen the tie rod end exactly one turn.
- Install the tie rod end ball stud to the wheel knuckle. If equipped with a torque prevailing nut, tighten to 18 ft. lbs. (25 Nm). Tighten the nut an additional 180 degrees (one-half turn). If equipped with a slotted nut for a cotter pin, tighten the retaining nut to 45 ft. lbs. (60 Nm) maximum to align the cotter pin slot. DO NOT back off (loosen) the nut to align the slots in the nut with the cotter pin hole in the ball stud. Install a new cotter pin.
- Turn the jam nut one turn. This should tighten the jam nut against the end of the tie rod threaded portion. Tighten the jam nut to 50 ft. lbs. (68 Nm).
- Check that the rubber rack and pinion dust boot is not twisted or puckered.
- Have a front end alignment performed at a qualified shop.