Upgrade Your Strip Burner with New Shocks and Struts
Installing new shocks and/or struts is the quickest, easiest, and cheapest way to improve your strip burner’s handling and ride characteristics. Original equipment suspension components, even those on cars marketed as high performance vehicles just don’t cut it for our hobby. They’re too squishy, causing too much lean and suspension rebound. In the best case scenario this can cause a reduction in your steering control and reactivity. Not long ago I write an article on how to change suspension coils. This companion piece will show you how easy doing shocks and struts can be.
Gather Your Tools
The tools you need for changing shocks are probably tools you’ve already got:
- Jack stands
- Wheel chock.
- Spring Compressor (depending on the cartridges/assemblies)
Of course, air tools will make the job go quicker and require less “elbow grease” but they aren’t necessary. If you’re installing new struts, you may or not need a spring compressor. This will depend on whether or not you’re replacing just the cartridges/ strut assemblies or if you’ve bought complete units that include upgraded coils, which is what I recommend.
Ways that Shock Absorbers Are Attached to the Vehicle
There are typically three ways that a shock absorber can be secured to your vehicle. The first type has a flange plate on the bottom and a single stem that has bushings and washers. Another type of shock absorber mounting has a large eyehole at the bottom instead of the flange. The third type has large eyeholes at both the top and bottom of the shock utilizing a single large bolt to secure the shock to the vehicle. See image above for representations of these.
Step 1: Get the Car in the Air
Block in front of and behind one wheel. If you’re doing front shocks, block one rear wheel, of doing the rears, block a front wheel. Place the jack and raise the car enough to comfortably get underneath and place jack stands under the frame rails behind the front wheels or in front of the rear wheels and lower the car onto the stands. Make sure you park on a flat and level surface and set the parking brake.
Changing Front Shocks Step 2: Out with the Old Parts-Upper Mount
On some cars you will need to turn the wheel completely to one side or the other to gain access to the upper mounting location on the upper control arm or frame, while on others the stem pokes through into the engine compartment and is accessed there. Remove the mounting bolt(s) from the top of the shock absorber.
Step 3: Remove the Lower Mounting Bolt(s)
Drop under the car and remove the lower mounting bolt(s) and remove the shock absorber through the bottom of the control arm.
Step 4: Install the Shock and Lower Mount
From underneath the car, slide the new shock absorber up through the opening in the center of the lower control arm until the lower mount(s) match(es) up. Leave it just a little loose to assist you in securing the upper mount(s). Prior to installation, if you’ve got the type of shocks with the stem and bushing/washer setup, install one washer and bushing, taking care to observe proper orientation of both.
Step 4: Secure the Upper Mount
Since raising the wheels off the ground unloads the suspension, you’ll most likely need to help the shock reach the upper mounts. Place the jack under the lower ball joint and slowly lift the jack to raise the control arm. Make sure you guide the upper portion of the shock absorber into its mounting. Once the mount(s) line up properly, install the bolts or nuts and tighten them.
Torque specifications vary by year and model, but average around 50 foot-pounds. With the upper mount installed and torqued, tighten the lower mounts. Again, the average torque spec is in the area of 50-60 foot pounds. If you’ve only lifted one side of the car, repeat Steps 1-4 on the other side and lower the car.
Changing Rear Shocks Step 2:
On some vehicles, this is actually going to be Step 1 of rear shock removal because you’ll need to climb into the car to get to the upper shock mounts. They’re located either in the trunk or, for hatchbacks, just behind and to the outside of the rear seats. These will be the type of shock that has the single stem with the bushings and washers.
Your car may have a plastic cup covering the upper mounting bolt, especially if you’ve got a hatchback. If the upper shock mounts are in the trunk, they’ll most likely be covered by a flap of the trunk carpeting. Remove the nut and washer/bushing combo from the upper shock mount. Once that is done, you can raise the rear of the car to get underneath it. Just be sure to block off a front wheel.
Step 3: Remove the Lower Mounts
With the rear of the car lifted and properly supported, slide under and remove the lower mounting bolt(s). On rear shocks this is usually going to be the large eyehole and single bolt type of mounting, although I have seen the two bolts and flange arrangement also. However, the cars we turn into drag racers are usually of the former type.
Step 4: Install the New Shocks and Attach at the Bottom
If your rear shocks are of the type with the long extended stem and bushing/washers type, install the large washer and one bushing onto the shock stem. Next, position the shock so that the bottom lines up with the mount and the top is pointed towards the upper mount. Thread the bolts in to the bottom mount, leaving them loose so you can wiggle the shock around if you need to.
Step 5: Secure the Upper Shock Mount
On most cars, you’re going to need to slowly and carefully lift the rear suspension to get the upper mount to match up properly. Secure the upper shock mount and torque it to the proper spec. After doing the other side, lift the car off the jack stands and lower it to the ground.
Changing Struts Step 2: Remove the Strut Cap Nuts/Bolts
Struts are tricky. They are an integral part of the vehicle’ suspension that affects the alignment. If you’re simply replacing the cartridges inside the strut canister, mark the strut and (if present) camber eccentrics (See image) to ensure that the alignment angles stay as close to where they should be as possible. Also mark the locations of the three or four nuts and studs on the strut cap that can be seen on the wheel well. (Marked by the arrow in the image below.)
Now you can remove the three (or four) nuts found on the wheel well under the hood and set the nuts aside. Removing the tire makes this job easier, but isn’t required. While you’re up here, unless you have the advantage of air tools, now is a good time to loosen (DON’T remove) the large nut securing the strut to the strut cap. If you’re planning on replacing just the cartridges, now would also be a good time to use a pair of Channellock-type pliers to loosen the cap nut on the strut tube. There may be a boot inside the coil that you will need to lift to gain access. Just break both of these loose a thread or two to ease their removal later.
Step 3: Remove the Main Mounting Bolts and Strut Assembly
Removing the tire makes this part of the job easier, but isn’t required. Place your jack under the lower ball joint and lift it enough to just support the control arm without raising it. Carefully disconnect any wiring harnesses and slide the brake line clamp off to release the brake line from the bracket. Remove the nuts on the bolts securing the strut assembly to the steering knuckle. Slowly lower the jack until you can remove the strut assembly.
Step 4: Compress the Coil Spring
Here’s where it can get dangerous. Lay the strut assembly on a solid surface and install the strut spring compressor properly. Double check to make sure it is installed properly. I like to wrap a piece of chain with a nut and bolt holding them together around the chain, or a heavy-duty rope for added safety. Carefully compress the strut coil spring until all coil tension is released from the strut cap. If you’re going the added safety route, now is when you will want to use the rope or chain.
Step 5: Remove Strut Cap and Coil
With the coil spring compressed and no tension on the strut cap, you can remove the large (7/8 inch or 15/16 inch nut at the top of the strut securing the strut cap to the strut rod. Many strut rods have a ¼ or 3/8 inch Allen head inside the rod to help you with loosening and removing the cap nut. With the nut removed slide the cap and coil off and carefully set both aside. If you’re going to be installing performance coils, go ahead and decompress the coil and set it aside and compress and safety the new coil.
Step 6: Remove and Replace the Strut Cartridge from the Assembly
If you’re replacing the whole strut assembly, skip this step. Using those large slipjoint pliers again, remove the strut tube nut and remove the strut cartridge from the strut tube. Pour any fluid trapped in the tube in a catch pan or bottle to properly dispose of later. Slide the new strut cartridge into the tube and slide the tube nut over the strut rod or spindle. Thread and tighten the nut. If you’ve got a vise, carefully clamp the strut assembly in it to tighten the nut. If not, wait until you get it back on the car.
Step 7: Reassemble the Strut
Make note of the up and down orientation of the coil, slide the strut coil over the strut assembly. Next, Slide the strut cap over the strut rod and thread the nut down. Tighten it as much as you can. If you need to, wait to apply final torque until after you have it installed.
Step 8: Reinstall the Strut
Slide the strut connecting bracket over the corresponding location on the spindle and guide the top of the strut (the strut cap) through the corresponding openings in the fender well. You may need to use the jack to lift the lower control arm enough to seat the top of the strut. Slide the two bolts through the strut mounts, slide the washers in place, and thread the nuts down. Tighten these enough that they don’t spin easily, but leave them loose enough that you can turn the bolts (not the nuts) with moderate effort using a wrench or socket. Finish guiding the strut cap into place and thread the three or four nuts in place. If you have camber eccentrics (oblong washers) tighten the strut cap bolts to approximately 30 foot pounds.
Step 9: Rinse and Repeat
Lower the car, and move to the other side and repeat steps 2-8 above to finish the installation portion of this job.
Step 10: Eyeball How the Tires Sit
MacPherson struts are an integral part of your car’s alignment. The alignment angle known as camber is adjusted either by turning the bolt with the oblong washer on the strut mount, or moving the strut cap around in elongated bolt holes.
With the car on the (flat and level) ground and all the nuts and bolts fairly tight, bounce on the front end a few times to settle the suspension. Now, eyeball the tire to ensure that it’s straight up and down, or maybe leaning just a hair toward the car. If it looks good, tighten everything up. If not, turn the camber eccentric bolt on the strut housing or tap the strut cap in or out to correct it. Once you’ve got it close, tighten everything up and head down to have the alignment checked professionally.
Wear safety glasses. You can’t replace your eyes if they are damaged while performing this repair.
Carefully read through the instructions for the strut coil compressor before attempting to use it. By compressing the coil, you’re putting an incredible amount of tension on it. If the spring breaks loose, it can do so with more force than a bullet. I also highly recommend using a safety chain or rope for anyone that doesn’t do this kind of work on a regular basis. I used to and still used a safety chain.
Never perform this type of work on a slanted driveway or incline. Not only will the angle through the suspension off and not let you get a good indication of the camber, the car could slide off the jack stands.
Note: You’ll notice in the linked video the presenter had a bit of a hassle getting the strut cap bolt loose. This is why if I don’t have the benefit of air tools, I like to break that nut loose with the strut still installed in the car. Just remember, only break it loose a thread or two, do NOT remove it until you have the coil spring fully compressed.