We fill our lives with barriers to protect us from the harsh realities of life. From the roof over your head to the parental lock on your cable box, the eternal issue is always the same: How long can this barrier protect our soft, ordered little world from the barbarians at the gates?
Fancy metaphors aside, this question applies every time you climb behind the steering wheel. Your pampered cab may be a world full of satellite radio serenades, wood-beaded massage seat covers and lavender-scented air fresheners, but the road is hard, winding and bumpy.
Lucky for you, your car suspension features snubbers or shock absorbers to help soften the ride. These key parts fall into two basic categories -- gas-charged and conventional. Neither type is immune to the wear and tear of the road. But just how long can your expect these tailbone-saving gadgets to last?
The short answer? Experts recommend replacing shocks every 50,000 miles (80,467 kilometers), but a great deal depends on how you treat your vehicle's suspension. Are you logging all those miles on the placid interstate, or are you off-roading on winding dirt roads through the untamed wild? Well, before that point, unusual suspension noises or excessive bounce or sway may indicate it's time to replace those shocks.
In this article, we'll look at the various factors that affect shock absorber longevity, as well as how to maintain and ultimately replace your shocks. So buckle up. Depending on the condition of your shocks, it might be a bumpy ride.
Factors Affecting Car Shocks Longevity
Let's go back to the barbarians at the gate analogy, shall we? The longevity of your walls of defense would depend a great deal on a number of factors. How often are the barbarians attacking, and how much damage do they inflict on the gates each time? How well do they hold up to the weather, and what are you doing to maintain them?
Pretty much the same holds true for the longevity of your vehicle's shock absorbers. Remember, whether you use gas-charged and conventional shocks, these devices deliver improved handling and a smoother ride by converting the kinetic energy of suspension movement during the drive into heat energy that dissipates through the hydraulic fluid in the shocks. Like the walls of an embattled city, there's only so much energy these shocks can absorb before they finally succumb.
As kinetic energy wears shocks down, it follows that more suspension movement has a negative effect on shock absorber life expectancy. If your morning commute consists of a smooth, unobstructed drive across level countryside, then your vehicle is probably enduring a minimum of suspension movement. Throw in some curves or a little stop-and-go traffic, and you have a lot more movement (and kinetic energy) slamming through those shocks. From there, gravel, hills and other road conditions only add to the stress on your vehicle's shocks, potentially subtracting from the typical 50,000-mile life expectancy. Even your style of driving and specific wheel and tire modifications can have an impact.
In addition to suspension movement, regional weather conditions and road contaminants can also take a toll on your vehicle's shock absorbers. After all, these are external mechanisms and regular drives through saltwater, sand or rough gravel roads can further wear your shocks down with abrasions or rust.
If you just drive the car to church on weekends, then this may all sound like great news -- not so much if you fill your Saturdays with muddy exertions into the wilderness. Luckily, you can take several steps to help maintain your defenses against all the road can throw at you.
Car Shocks Maintenance
The most important step in car shocks maintenance is simply to remember that your car has them to begin with. You can tell a great deal about their performance by simply feeling your car's suspension as you drive.
Motor Trend magazine also suggests taking your vehicle out to a secluded parking lot, accelerating to 10 miles per hour (16 kilometers per hour) and hitting the brakes. If the front of the vehicle keeps bobbling after you come to a stop, then your shocks are likely shot [source: Motor Trend].
When you're not on the road, you can get a closer peek by getting on your hands and knees and looking at these ride-softening little gadgets. If you see dents in the shock tubes, leaking oil (though a slight oil film over the lower portion of the shocks is OK), then chances are you're in the market for some new shocks.
You should also keep an eye out for loose mounting bolts and worn mounting blushing, which may also result in a rattling noise while you're driving. Your shock absorbers need a firm mounting to work properly, so you might have to replace loose bolts and blushings. In some cases, this requires the replacement of the shock absorbers themselves as some designs include the blushing as part of the shocks.
Your shocks are just one part of the vehicle's overall suspension system, so you'll want to keep an eye on such components as ball joints and springs as well.
Worn shocks don't just hamper driver comfort; they can harm overall suspension performance and reduce brake efficiency, cornering ability and antilock brake system effectiveness. So when shocks go bad, it's out with the old and in with the new.
Replacing Car Shocks
Driving on busted shock absorbers is neither safe nor comfortable, so when the oil starts leaking and the car never stops bobbing like a toy boat in a bath, then it's time to deal with replacing those shocks. As with all vehicle maintenance projects, you might want to have the task carried out by a professional mechanic. However, if you're feeling confident in your own abilities, it's certainly a task you can carry out in your home garage.
First, you'll want to consider what kind of shocks to install. Essentially, you have two choices: stick with the original equipment installed by the manufacturer or upgrade to aftermarket shock absorbers. If you barely know what a shock absorber is, then the former choice likely suits you best -- as does taking your vehicle to a professional mechanic. However, many car enthusiasts choose to upgrade, trading in their old shocks for models offering improved vehicle performance or longer part life. Whichever route you choose, you can expect to spend between $20 and a $120 on each new shock. Just make sure your new shocks match up with your vehicle's make, model and year, because this is definitely not a situation where "one size fits all."
To replace your shocks, you'll need access to your vehicle's underbody -- and this means elevating your vehicle on safety stands and possibly removing the wheels as well. Then, you'll need to find the shock mountings and loosen the mounting hardware. Typically, you can spin the mounting hardware off with a socket wrench. If the shocks are electric, then you'll need to unplug it. If the piston rod spins when you're trying to remove the upper mount, then you'll want to anchor it in place with vice grips. If your shocks are mounted on studs, then you'll need to remove the nuts from the stud mounting.
Once you've pried the old shocks the rest of the way out, it's time to fasten on the new ones -- which typically come with brand-new lower mounting bolts. You might need to bleed air out of new shocks to ensure smooth operation. To do this, simply hold the shock in an upright position (as if it were installed), extend it, then turn it upside down and compress it. A few repetitions should do the trick. If you're installing adjustable shocks, Popular Mechanics magazine suggests starting out at the "soft" or "normal" setting.
Finally, all you have to do is follow installation instructions for your new shocks, making sure to apply thread-locking compounds to the studs to ensure stability. Once everything is installed tightly, your shocks are good for another 50,000 miles (80,467 kilometers).
Explore the links on the next page to learn even more about your vehicle's suspension system.
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- "Do-It-Yourself Projects: Replacing Shock Absorbers." Mobil Oil. (Oct. 7, 2009) https://www.mobiloil.com/USA-English/MotorOil/Car_Care/DIY/Replacing_Shock_Absorbers.aspx?pg=1
- Harris, William. "How Car Suspensions Work." HowStuffWorks.com. May 11, 2005. (Oct. 7, 2009) http://auto.howstuffworks.com/car-suspension.htm
- Knowles, Don and Jack Erjavec. "Techone: Basic Automotive Service And Maintenance." Thompson Delmar Learning. 2005. (Oct. 7, 2009) http://books.google.com/books?id=Dp_LUwqIW7sC&printsec=frontcover &source=gbs_v2_summary_r&cad=0#v=onepage&q=&f=false
- "Shock Absorbers." Motor Trend. Sept. 1, 2002. (Oct. 7, 2009) http://www.motortrend.com/womt/112_0209_shock_absorbers/index.html
- "Shock Absorbers -- The Hidden Danger." AutoWeb.co.uk. (Oct. 8, 2009) http://www.autoweb.co.uk/article/632
- Weissler, Paul. "Replacing Shock Absorbers." Popular Mechanics. December 1999. (Oct. 7, 2009) http://www.popularmechanics.com/how_to_central/automotive/1272396.html?page=1