Story and photography by Ryan Lee Price
There are many ways to tell if you need to replace the shocks on your car or truck. They wear out over time and the older they get the higher the likelihood of them failing completely. If your car has excessive bouncing, nose dives into stops, pitches into turns, or squats down in the back on acceleration, it is likely your shocks need replacing. Bad shocks will cause your tires to bounce up and down, creating worn “cups” in the middle of your tires. Look at the shocks themselves, if they are leaking oil, or damaged, or the pistons are rusted, it’s time to replace them.
New shocks will not only give your vehicle a smoother ride but can also help it stop quicker and get better gas mileage.
Replacing worn out rear shocks on a 2004 Ford F-150 is easier than you might think, and odds are good you have all the tools you’ll need in your garage already. This truck employs multi-leaf springs on each side of the axle to support the load of the truck, but it is the shocks that take most of the brunt of day-to-day driving. When you hit a pothole or go over a speed bump, it’s the shocks keeping the ride smooth.
There’s no need to raise the rear wheels or remove the tires. In fact, if you keep your vehicle on the ground, you don’t need a jack stand to support the rear axle.
The tools you’ll need for this job are straightforward: an 18mm wrench, 15mm socket, a small pry bar, hammer and a can of penetrating spray. Of course, lay out out something under your vehicle, like a piece of cardboard; it will make it slightly more comfortable and will catch any dirt or drippings.
It is always best practice when working on something in pairs on your vehicle to completely do one side before attacking the other. This way, if something goes amiss or afoul, you’ll have the other side to use as a reference. In this case, note the orientation of the shock itself (some are piston up and some are piston down—ours is up) at its position in relation to the other components, specifically the brake lines.
If it has been a while since they’ve been replaced, count on the bolts (especially the bottom ones as they are more prone to water and debris) to be well in the habit of being there, and needing a dousing of penetrating oil to coax them out.
Once you’ve given the penetrating oil time to do its business, start with the top. The nut is 18mm while the bolt head is 15mm. If your shocks have been on for quite a while and the penetrating oil isn’t doing the trick, you might need a larger wrench or a breaker bar to free the nut. Luckily, ours just needed a lot of muscle.
It is the same situation on the bottom, the nut is 18mm while the bolt head is 15mm. Put all your effort into loosening the nut first before trying to loosen the bolt. The nut is larger and can take a lot more pressure.
With the shocks out, it is time to prep the new ones. Your make and model of shocks might vary, but since this particular pair were made to go on a variety of different vehicles, it came with a few different size sleeves to go inside the bushings. To help them slide in, spray a little oil inside the bushing and around the sleeve.
There are a variety of ways to do this. You could use a press or a simple bench vise, but the sleeves slipped right in with a little persuasion from a hammer. Make sure they go in straight before you tap them in all the way so you don’t damage the rubber bushing.
Simply slide the bolts through the ends and tighten the nuts down. Make sure to inspect the hardware before you reuse it. It should be free of damage. The manufacturer suggests for these shocks a torque spec of 66 lbs-ft. but yours may differ.
The total time for this procedure was only about 30 minutes and it used minimal tools. It is considered an easy job and can be done by anyone with limited automotive experience, so there is no reason to take it to a mechanic. For more information about shocks and your vehicle’s suspension system, subscribe to ChiltonDIY.
Not only is Ryan Lee Price a freelance writer specializing in automotive journalism and a former long-time magazine editor, he is part of the technical editorial team that provides content for most all of the Chilton products. He currently resides in Corona, California, with his wife Kara and their two children.