Most vehicle owners never think twice about the components that comprise the power steering. As long as the steering wheel turns smoothly to the left and right, everything is A-OK. However, one of the most important parts that protects the inner components that drive the power steering system is the input shaft seal. Because the power steering system in most cars today is hydraulic, seals are used to prevent fluid from leaking out and to reduce the potential of debris being introduced to the mechanical parts that drive the power steering system. This is the job of the power steering input shaft seal and why it's very important to the complete operation of the power steering system. When the power steering input shaft seal is damaged, hydraulic fluid can leak from the power steering input shaft, and eventually cause the system to overheat or break down entirely.
Part 1 of 1: Replacing the power steering input shaft seal
- Boxed end wrench or ratchet wrench
- Grease pen
- Hydraulic line wrenches
- Large flat blade screwdriver
- Line press and press fittings
- Liquid containment drain pan
- Multiple probes and seal removal screwdrivers
- Replacement input shaft seal kit
- Safety equipment (safety glasses & gloves)
Step 1: Disconnect the battery and lift the vehicle. Before removing any parts, locate the vehicle's battery and disconnect the positive and negative battery cables.
- Note: This step should always be the first thing you do when you work on any vehicle.
Lift the vehicle with a hydraulic lift or jacks and jack stands.
Step 2: Remove the power steering gear from the vehicle. This step is unique to the type of vehicle you are working on, so refer to your service manual for instructions on how to remove the power steering gear from the vehicle.
Step 3: Place the gearbox on a clean workbench and clean it. Before you remove any seals, it's a good idea to completely clean the outside of the gear box.
Using a good chemical solvent, spray the outside of the gearbox completely and remove as much debris, grime and other materials from the outside of the gearbox before disassembly.
This will remove most debris and reduce the potential of any materials getting inside the gear box once the cover has been removed.
Step 4: Remove the face cover from the input shaft. Once the gearbox has been cleaned, the first item you'll remove is a face cover on the input shaft itself.
This simply slips off the input shaft and is designed to be a first line of defense for debris.
After removing this item, place it aside as you'll need to reinstall it unless you have a new one in the input shaft seal kit.
Step 5: Mark the cover and housing with a grease pen before removing. Using a grease pen or other material, make sure to mark the location of the outside input shaft cover on the housing.
This will help you reinstall the input cover correctly once you've replaced the seals inside.
Step 6: Remove four bearing cap bolts and the cover. There are four bolts that hold the bearing cover onto the gear housing. Remove these four bolts, then remove the input shaft bearing from the housing.
Cover the housing with a clean shop rag to ensure no contaminants enter the inside of the gear set.
- Warning: Do not turn the input shaft with the cover removed. Doing so will misalign components inside the unit and cause serious damage to the gearbox once it is reinstalled. It's also important not to allow any debris or dirt to enter the housing.
Step 7: Pry the soft seal from the cap cover. Using a probe, pry the old dust seal from the inside of the input shaft bearing.
This will typically look like an o-ring or a flat washer based on the type of gearbox you're working on.
Step 8: Drive the input shaft seal using a seal driver. The input shaft seal needs to be pushed through the bearing center.
This is done by using a seal driver with a press or a perfect sized socket with a hammer. It's best to use the press and seal driver method here.
- Tip: Some gear bearings will have a protective washer that is covering the input shaft seal. If this is the case, remove the washer first, then drive the seal out with the bearing driver.
Step 9: Remove the bearing cap cover o-ring. If your installation kit has an o-ring, it needs to be replaced at the same time you remove the input shaft seal. Remove the o-ring with a metal probe or flat blade screwdriver.
Step 10: Completely clean the input shaft bearing. Using a can of high-quality solvent, clean the input shaft bearing and dry it completely with a clean rag before reinstalling the new input shaft seal.
Step 11: Install the new input shaft seal. Place the cover face down, lightly coat the outside of the input shaft seal with oil, and install the new input shaft seal using an arbor press or a seal driver. Reinstall the components in the reverse of the removal.
First, install the new o-ring and insert the new dust seal. Install the cover back onto the steering gear, making sure to align it with where you marked earlier.
Install the four bolts connecting the bearing on the steering gear. Make sure to torque correctly to the manufacturer's recommendation.
Install the face shield cover over the input shaft. Reinstall the gearbox onto the steering housing and reinstall onto the vehicle.
Step 12: Prepare the car for driving. Fill the power steering fluid reservoir to the correct indicator line and reconnect the battery cables.
Step 13: Test the vehicle. Start the vehicle and inspect underneath for any leaks coming from hydraulic lines.
Let the engine run to build hydraulic pressure inside the power steering system and top off the fluid once the vehicle has run for a few minutes.
Test the steering while the car is still in the air so as to not put a load on the new input shaft seal and gear box. Finally, take the vehicle for a 10 to 15 mile road test. This ensures the entire steering system works as it is supposed to on varying road conditions.
Before attempting this repair, make sure you have the right tools and experience with steering and suspension components. If you've read these instructions and still don't feel confident in completing this repair, please contact one of the local ASE certified mechanics at YourMechanic to complete the power steering input shaft seal replacement job for you.
This article originally appeared on YourMechanic.com as How to Replace a Power Steering Input Shaft Seal and was authored by Timothy Charlet.