Suspension System Repair: How To Diagnose & Replace Shock Absorbers Part 3

• Socket wrenches (either metric or SAE sizes, depends on vehicle make & model).
• Combination wrenches(as above, either metric or SAE sizes, depends on vehicle make & model).
• Large flat-bladed screwdriver or small flat pry bar.
• Vise-Grip® or other locking type pliers(optional – needed only if shock absorber uses threaded rod for upper attachment).
• Can of Rust Penetrant, such as WD-40® or similar.
• Jack and Jackstands with which to raise and support vehicle.
• Rags etc. for handling and cleanup.

Parts:

New shock absorbers are a very common item and can normally be purchased from a variety of sources, both online and offline. Nearly all auto parts stores and car dealers stock them. When ordering, be sure to tell the salesperson the year, make, and model of your vehicle. In some cases, you will be asked to provide additional details such as engine size and/or VIN number.

Before beginning repairs of the suspension system on your vehicle, there are a few decisions regarding the choice of parts which you will use for the job. Choosing good quality parts is essential not only in order to assure that the job is done right the first time, but also to help insure the safety of you and your passengers. When purchasing parts, be sure that you ask about the length and type of warrantee which covers the parts.

The work:

Park your vehicle in a well lighted area, inside or outside. Make sure that there is plenty of room to work around each wheel and to keep tools close at hand.

1. Place the jack at an appropriate spot underneath the vehicle and then jack the vehicle up so as to lift one wheel,  as if changing a tire. Place a jackstand underneath the vehicle for support, preferably at a location along the frame.

2. Remove the tire & wheel. After the wheel is removed, you can then locate the lower attachment bolts and nuts of the shock absorber. Using the appropriate wrenches, remove said bolts and nuts. It may be necessary to spray them with rust penetrant in order to aid removal. If there are any washers on the bolt, make a note of their positions for re-installation later. If you find that the bolt will not slide out after the nut is removed, see the following step.

3. If you cannot push the lower mounting bolt out of the shock absorber after removing the nut, then you may need to do the following:

a) Make sure that the vehicle is securely supported on jackstand(s).

b) Reposition the jack underneath the lower suspension arm. This is usually the part that the lower portion of the shock absorber is attached to. Raise the jack so as to put a slight upward pressure on the suspension arm. The idea is to relieve pressure on the lower shock mounting bolt so that you can remove it.

4. After you have removed the lower bolt and nut, you are ready to remove the upper mounting. This might require only that you remove a bolt and nut similar to the lower mouning bolt, or it may be a rod which comes out of the upper portion of the shock absorber and attaches near the top. In case of the latter, you will need to do the following:

a) The rod will have a nut on the end which is how it fastens to the vehicle, and may also have some metal washers and rubber grommets underneath the nut. Using an appropriate wrench or socket wrench, remove the nut. Spray with rust penetrant if needed. As you turn the nut in order to remove it, the rod will probably turn also, which will not allow the nut to unscrew. If this happens, then….

b) Use locking (vise-grip) pliers to clamp around the rod in order to keep it from turning. The idea is to keep the rod from turning so that the nut can be removed. Don’t worry about damaging the rod with the locking pliers – You’re replacing this shock absorber anyway. If there are washers and grommets underneath the nut, then note their positions and remove them.

5. After the shock absorber is free at both ends, you can remove it from the vehicle. In some cases you will need to slide it through a hole in the suspension arm in order to remove it.

6. Now that you have the shock absorber free, compare it to the new replacement unit in order to assure that the new one is the correct part. The new shock absorber may have a plastic strap connected to it in order to keep it from expanding inside the shipping box. If so, leave the strap intact for now.

7. Using any washers and grommets which you may have removed in the previous step, install them onto the threaded rod on the new shock absorber. Remove the aforementioned plastic shipping strap if it exists.

8. You can now install the new shock absorber into the vehicle in place of the old one. Start by setting the new unit into position, and attach the upper end first. Install the mounting hardware loosely.

9. Next, attach the lower end. You may need to compress the new shock absorber a bit in order to align the mounting holes. If so, use slow, gradual pressure. A gradual pressure will compress the shock absorber.

10. After the new shock absorber is securely in place and all hardware attached, you may tighten the mounting nuts & bolts on both ends. When tightening, apply the same amount of torque as was required to remove the bolts from the old unit. A correct installation will have all nuts, bolts, washers and other hardware in their correct positions on the new shock absorber as compared to the old one.

11.  Congratulations! After all mounting hardware is tight, you are done with the first shock absorber. Double check your work to insure that all hardware is tight and in the correct locations. Remount the tire & wheel, and lower the vehicle back down.

Follow the same general procedures as outlined above in order to replace any other defective shock absorbers on your vehicle. After all needed replacements have been done and all wheels reinstalled, be sure to look around the vehicle for any tools, etc. which may get run over if not moved.

Take your vehicle on a short, slow test drive to test the new ride!