How to Change a Steering Boxby KaRinda Baker
If your vehicle is not equipped with a rack-and-pinion type steering system, more than likely it’s equipped with what’s called a frame-mounted power steering gearbox. While these steering boxes are simple in design and may not appear to do much when you look at them underneath the hood, they help you control your vehicle. When they wear out, they can cause potentially dangerous maneuverability problems. When this happens, it will be time to repair or replace.
Park the vehicle on a flat part of the ground and apply the parking brakes. Remove the battery terminals from the battery post. Allow the engine to cool. Put a plastic drip pan underneath the power steering box. Disconnect the high-pressure hose that routes the hydraulic fluid through the power steering box (skip this step if your vehicle does not have power steering) using a line wrench.
Plug the openings where you removed the hose with a rag. Pull the pitman arm away from the steering linkage using a tie-rod puller. Soak the parts with some liquid wrench and then try again later if you are finding it difficult to separate the parts. Separate the steering shaft from the power steering box input shaft.
Locate the large bolts that attach the power steering box to the frame. Remove these bolts from the steering box using a wrench. Try lowering the unit from under the lower part of the engine compartment. If that is not possible because of space constraints, try removing the alternator and bring the box through the upper part of the engine compartment.
Inspect the parts you removed from the power steering box for proper functioning such as the ball joint on the pitman arm for too much play. Put the old pitman arm on the new steering box gear. Install the steering box using the steps you took to remove in reverse order. Torque all of the hardware you removed back to the manufacturer’s specifications as best you can if you no longer have the manual. Connect the terminals back to the battery.
Fill the power steering reservoir with new power steering fluid. Ask a helper to start up the engine and turn the steering wheel sharply back and forth to the right and then the left while you check for fluid leakage. Ask your helper to shut off the engine. Recheck the reservoir and add more fluid if needed. Recheck the fluid level in the system three days after the installation.
- If you continue to have problems, contact a local mechanic who can diagnose your power steering problem(s) by inspecting the entire power steering system. A mechanic will also replace parts that may be causing problems with the steering such as the ball joints and power steering pump.
Things You'll Need
- Drip pan
- Line wrench
- Tie rod puller
- Liquid wrench
- Hydraulic fluid
- Adjustable wrench
- The power steering box is heavy, so support the unit with your hands to avoid injury.