Land Rover Discovery 3: Front Air Strut Replacement

The suspension system of your Land Rover Discovery is one of the most crucial systems of your vehicle. It functions to provide steering stability and handling, maximize the contact between the tires and the road surface, evenly support the weight of your SUV and optimize passengers ride comfort by absorbing and dampening shocks. Thus, the suspension systems take more beatings than any other system in your vehicle.

The suspension system is made up of tires,air struts, air suspension compressor, arms, linkages, bars, joints, and bushings. These components are situated between the road and the vehicle frame. The system requires the wheels and tires to move up and down in such a way as to absorb the shocks from irregularities on the driving surfaces.

The air struts or air shocks in your LR3 replaces what is known as a shock absorber in most cars. They are used mostly in luxury cars and function primarily to control and smoothen the suspension movement and keep the tires on the road. The air struts are the main structural components of your LR3 suspension system. It provides support for the entire system, aligns the wheels and tires and bears most of the load placed on the vehicle’s suspension. The struts, therefore, affect handling, ride comfort, braking, wheel alignment as well as wear on other components of the suspension system.

It's therefore important that you replace the air struts on your vehicle when they wear out. Fortunately, they tend to last for a long time. However, when they start to leak air, you’ll experience sagging, poor ride comfort and handling. And it’s time to replace the air shocks.

The land rover dealership will charge from $2000 to 2500 to replace your front shocks. Doing it yourself will cost you about 2 hours and maybe a bruised knuckle.

Tools you need.

22mm wrench, 24mm wrench, 15mm wrench,12 mm wrench, half inch ratchet, 22mm socket, and extension bar. Wheel spanner, jack and jack stands/wooden blocks

Step-by-step procedure:

1. 1. Remove the heat shield. Pop open the hood and locate the heat shield. The air shock is secured to the vehicle frame at the top by three 15mm bolts. The two nuts in front can be accessed easily from the wheel well. But the third nut can be better accessed from the engine bay. Unscrew the heat shield and pull it off to expose the 15mm nut. Use the 15mm socket with a long extension and a ratchet to remove this nut. For the passenger's side, you may have to remove the engine cover to get at the 15mm nut because the extension needs to be aligned at a different angle. Also, to better work at this more difficult angle, you should use a swivel attachment with the 15mm socket.

2. 2. Remove the tires. Loosen the lug nuts, place block behind the tires at the back and jack up the vehicle. Place jack stands or wooden blocks underneath your car for support. Then take the front tires off.

3. 3. Take the pressure out of the system. On the passenger’s side, inside the plastic inner fender splash shield, there’s a valve block which supplies air to the two front air struts. Partially remove the splash shield to gain access to the valve block. The valve block is attached to the frame with 3 grommets and can be easily pulled off. Three air lines (small pipes) run into the valve block. The green line at the bottom supplies air to the driver’s side air strut while one of the black lines is a supply line and the second black line at the top supplies air to the passenger’s side air struts. Use a 12mm wrench to slack the connection nuts and let the air out slowly. Allow some time for the system to be sufficiently depressurized.

4. 4. Take the bottom bolt off. The air strut is attached to the control arm at the bottom with a 9.5-inch long bolt. Use the 22mm socket and breaker bar to hold the bolt in place and with the 24mm wrench remove the nut. Tap the bolt with a rubber mallet till it’s flush with the control arm. Place a wrench on the bolt head and tap with the mallet till the bolt comes off.

5. 5. Remove the remaining two 15mm at the top. Now that the bottom of the air strut is free, remove the two remaining 15mm nuts with a long 15mm wrench for better leverage. While removing the nuts make sure to support the air strut because only the air line supports it at this point, and you wouldn’t want to damage that.

6. 6. Disconnect the air line. With the two 15mm nuts off, gently maneuver the air strut to expose the air line. Use the 12mm wrench to disconnect the air line. Wiggle the air strut out.

7. 7. Install the new air strut. Fit the new air strut inside the bay. Trace the air supply line and unclip it from the frame to give you about three more inches to work with. Unscrew the connection nut for the air line on the new strut. Remove the white plastic insert inside and replace it with the air line. Ensure to properly fit in the small ring under and screw back the assembly.

8. 8. Tighten the 15mm nuts. From the wheel well, tighten the first two 15mm nuts at the top of the strut. Go through the engine bay to tighten the last nut at the back.

9. 9. Secure the lower part of the strut. Use the jack to raise the control arm, so it aligns with the opening at the bottom of the air strut. Pass the 9.5-inch bolt through and tighten the 24mm nut.

1. 10. Connect the valve block. Tighten the nuts you loosened to release air from the system. Clip the air lines back to the frame. Fit the valve block back onto the frame and close the fender splash shield. Replace the heat shield in the engine bay.

1. 11. Put back the tires.

2. 12. Remove the jack stand. And lower the vehicle till the tires touch the ground.

3. 13. Energize the system. Start up the engine and allow it to run for a while.

4. 14. Check for leakages in the system. Allow the car to sit for some time and observe the change in ride height immediately after the strut replacement and after about 12 hours. A reduced level indicates that there are still some leakages in the system. You may need to refer to your Land Rover dealership for further troubleshooting. Also listen for hissing noises near the newly replaced struts.

5. 15. Then take it for a test drive. And glide smoothly over the roughest part of your neighborhood roadway