Power Steering Rack Replacement

Introduction

Procedure contributed by Raymond Hartle based on work performed on a 1987 944S. The power steering rack on the 944 is a serviceable component, and replacement is within reach of a careful home mechanic with the right tools. Plan for a front-end alignment after completion.

Note: Some European models may require a 32mm socket rather than 30mm for the steering shaft nut.

Tools

• 19mm socket
• 17mm socket
• 13mm socket
• 10mm socket (belly pan)
• 30mm socket (see note above for European models)
• 6mm Allen key
• 8" and 12" 3/8" drive extensions
• Cold chisel
• Flat chisel or drift
• Gear puller
• 3" vise with soft jaws
• 3-quart drain basin

Parts

• Power steering rack (part number 933-347-011-24) — a rebuilt long rack includes new boots and tie rod ends (not assembled)
• Tie rod ends (part number 944-347-033-23; quantity 2 recommended if mileage warrants)
• New bronze crush washers for the line fittings
• Dexron II or III ATF (power steering fluid)
• Miscellaneous hardware as needed

Procedure

1. Preparation

Block the rear wheels, apply the parking brake, and disconnect the negative battery lead. Loosen the front wheel lug nuts, then raise and safely support the vehicle on jack stands at the frame rails (about 18 inches of ground clearance works well). Remove the front wheels.

Remove the 7 belly-pan (undercover) bolts with a 3/8" drive ratchet and 10mm socket, and remove the belly pan.

Place the drain basin under the power steering pump. Using the 19mm wrench, remove the pressure line from the pump and let the fluid drain into the basin. Turn the steering wheel lock-to-lock several times to help void the steering gear of fluid; allow it to drain completely. Have rags and fluid catch materials ready.

2. Front Sway Bar Removal

Disconnect the sway bar from the control arms on both sides. Unbolt the sway bar clamp bolts and remove the sway bar from the vehicle to gain access to the rack.

Torque specs for reinstallation:

• Sway bar to control arm: 24 N·m18 ft·lb
• Sway bar clamp bolts: 23 N·m17 ft·lb

3. Disconnect Tie Rod Ends

Using the 19mm wrench, loosen the locking nut on each tie-rod-end ball joint until it sits just above the end of the stud. Use a small gear puller to separate the tie rod ends from the steering knuckles. (You may also be able to pop them out by rapping on the end of the steering knuckle, avoiding the need for a puller.) Count and record the number of turns required to remove each tie rod end from the rack — this will be used to set approximate toe during reinstallation.

Torque spec for reinstallation:

• Tie rod locking nuts: 40 N·m30 ft·lb

Caution: Avoid a pickle fork — it almost always tears the ball-joint rubber boot, so it should not be used if the tie-rod end is to be reused.

Note: If the tie rod ends use self-locking nuts (rounded top, no washer or cotter pin), replace them — they are not considered reliable for reuse. Standard nuts with locking washers are a suitable substitute.

4. Disconnect Steering Column U-Joint

Locate the steering column universal joint clamp at the firewall/bulkhead. Use the 6mm Allen key and 13mm socket to loosen the pinch bolt. Slide the u-joint off the steering rack input shaft. Mark the shaft and clamp position before removal to ensure correct reassembly phase alignment.

5. Rack Removal

Use the 6mm Allen wrench to remove the return line from the steering gear housing. Remove the pressure line support clamp from the rack housing along with the ground wire attached at that location. Then remove the 4 rack mounting bolts with the 13mm wrench. Slide the rack out of its mounting journals while simultaneously slipping off the steering universal joint as you lower the rack assembly.

Because the replacement rack is usually bare, transfer the following items from the old rack to the new one:

• High pressure line support clamp and its 10mm bolt
• Rack line rubber spacer
• Plastic compensating line with its two plastic L-shaped fittings (they pull straight out)
• Left and right side mounts

Torque specs for reinstallation:

• Rack mounting bolts: 23 N·m17 ft·lb
• High pressure line (rack connection): 20 N·m15 ft·lb
• Return line: 20 N·m15 ft·lb

6. Tie-Rod Removal from the Rack

Secure the rack in a vise using soft jaws to avoid damage to the rack housing. Use the cold chisel and hammer to straighten the locking tab on the tie rod locking collar. Use the flat chisel or drift against the locking collar flats to unscrew the tie rod assemblies from the rack ends.

Caution: Apply force in a controlled manner — the locking collars can be tight. Do not allow the rack to rotate in the vise; this can damage the internal seals.

7. Tie-Rod Installation in the Rack

Thread the tie rod assemblies onto the new rack ends. Torque to specification, then bend a locking tab into a flat on the collar to retain the setting.

Torque spec:

• Tie rod assemblies to rack: 70 N·m52 ft·lb

8. Rack Installation Preparation

Before installing the replacement rack, verify that the tie rod ends are threaded on the same number of turns recorded during removal. This provides approximate toe alignment to get the car safely to an alignment shop.

Get all of the original parts back onto the new rack first — a reverse-of-removal install is not as simple as it sounds here. The following assembly order works well:

1. Slide the right and left side mounts into place.
2. Install the rubber spacer under the rack line.
3. Attach the high pressure line using new bronze crush washers (torque to 20 N·m15 ft·lb); tighten it as firmly as possible with a long 6mm Allen wrench.
4. Loosely attach the support clamp with its 10mm bolt (it has to be removed again later).
5. Insert the L-shaped fittings on the ends of the compensating line.
6. Snake the compensating line into position and firmly push the fittings into place on the rack housing.

9. Rack Installation

Center the rack first. Remove the threaded plastic plug from the view port on the underside of the steering gear housing, then turn the steering shaft until the red dimple in the rack gear aligns with the view port. With it aligned, thread a 10×1×35 mm bolt into the view port to lock the rack in the centered position; the bolt should have a smooth, ground tapered end to engage the dimple. (Alternatively, drop a ball bearing into the view port to engage the dimple, then thread an unaltered bolt in to lock the ball bearing in place.) Centering the rack is essential — an off-center rack leaves the steering mis-phased.

Place the rack into position on the passenger side and finger-tighten one passenger-side mounting bolt, letting the driver's side hang slightly. Turn the steering wheel until it is straight (an assistant helps). With the universal-joint clamp split aligned exactly over the flat of the steering gear shaft, push the rack up into position so the clamp slides down onto the shaft. Hand-tighten the upper driver's side bolt; if the clamp did not seat fully, tap it down lightly until none of the shaft flat shows beneath it. Install and tighten the clamp pinch bolt, then finger-tighten the remaining two mounting bolts (work carefully to avoid cross-threading the aluminum cross member). Torque the rack mounting bolts to specification.

Install the high pressure line mounting clamp and ground wire. Attach the high pressure line to the power steering pump using new bronze crush washers and torque to specification. Attach the return line to the rack housing, also with new bronze crush washers, and torque to specification. Use a plastic tie wrap to bundle the high pressure line and compensating line to the rack, at the same location as the rubber rack line spacer.

Remove your centering bolt (or ball bearing), then refit and tighten the view-port plastic plug.

Torque specs:

• High pressure line (pump connection): 45 N·m33 ft·lb
• Return line: 20 N·m15 ft·lb
• High pressure line (rack connection): 20 N·m15 ft·lb
• Rack mounting bolts: 23 N·m17 ft·lb

Reconnect the tie rods to the steering knuckles and torque the locking nuts to 40 N·m30 ft·lb, applying enough pressure to the ball-joint stud to keep it from turning in the knuckle. Install the fresh-air tube and the driver's side sway bar mounting bracket. Reinstall the sway bar by connecting the ends first (sway bar to control arm: 24 N·m18 ft·lb), then jack the bar up until the clamps align with the brackets — both sides simultaneously — and install the clamp bolts (23 N·m17 ft·lb).

10. Bleeding the System

Install the wheels and lower the car off the jacks. Fill the power steering reservoir with Dexron II or III ATF. Do not start the engine until the reservoir is filled.

1. Reconnect the battery and start the engine; wait a few minutes to give the fluid time to find its way.
2. Slowly turn the steering wheel lock-to-lock until no more air bubbles appear in the reservoir and the fluid level stays constant.
3. Check the reservoir level and add fluid as needed.
4. As a final check, compare the reservoir level with the engine stopped versus running. If the level rises more than 10 mm, air remains in the system — repeat the bleeding process.
5. Check all connections for leaks.
6. Reinstall the belly pan.

Note: A small amount of fluid weeping at freshly torqued line fittings is normal initially. Recheck after the first drive and retorque if needed.

Schedule a front-end alignment after any steering rack replacement.