The struts on a Subaru Impreza are a complete suspension assembly. They act to help dampen the bumps and vibrations picked up from the road while driving. Eventually, the strut assembly will wear out and need replacement. If you do not replace your struts, you could experience excessive tire wear and premature failure to other suspension parts, such as ball joints and even CV joints.
Open the hood of the Impreza and locate the upper-strut mounts. These will be located on the side of the fender in the engine bay. Loosen the upper-mounting bolts for the driver's side with the socket wrench turning the nuts counterclockwise to loosen. Remove the sway bar link from the top of the struts if your Impreza has one. Not all models will have this option.
Spray the penetrating oil on the pinch bolt. Let it sit for about 15 minutes, and then spray it again. This time, let it soak for 5 more minutes. Remove the pinch bolt using the socket wrench. Turn counterclockwise to remove. You may need to use a breaker bar for this. Place the breaker bar over the end of the socket wrench and turn counterclockwise. The added leverage should make it much easier to remove.
Separate the upper strut from the spindle housing. To do this, use a pry bar and hammer. Wedge the pry bar between the spindle housing and the upper strut. Then, hit the pry bar with a hammer.
Place the floor jack under the frame of the vehicle in the front and jack it up slowly. As you do, the strut assembly will decompress. Be aware that the assembly may pop, so stay clear of the strut assembly until you are certain that there is nothing holding the struts in place and that it is decompressing.
Place jack stands under the Impreza at the pinch welds in the front or under the frame and lower the vehicle onto the jack stands. Loosen, but do not remove the front brake line and support brackets. Check that you do not accidentally damage the ABS sensor attached to the wheel bearing assembly.
Loosen the lower-strut bolts and remove them to pull the strut down through the bottom of the wheel well. Install the new strut assembly. Installation will be the reverse of removal. Repeat this process for the passenger side and for both rear struts. For the rear struts, the upper-mounting bolts are located in the trunk near the wheel well.
