Question:How do I know if my vehicle really needs new
shock absorbers?
Answer:You need new shocks (and/or struts) if your original
shocks (or struts) are worn out, damaged or leaking. Leaking
is easy enough to see (just look for oil or wetness on the outside
of the shock or strut) as is damage (broken mount, badly dented
housing, etc.). But wear is often more of a subjective thing
to judge. There are also instances where the original equipment
shocks may not be worn, damaged or leaking, but may not be adequate
for the job they're being asked to do. In such cases, upgrading
the suspension with stronger, stiffer or some type of special
shock (or strut) may be recommended to improve handling, for trailer
towing, hauling overloads or other special uses.
Shocks and struts do not require replacing at specific mileage
intervals like filters or spark plugs, but they do wear out and
eventually have to be replaced. How long a set of original equipment
shocks will last is anybody's guess. Some original equipment
shocks may be getting weak after only 30,000 or 40,000 miles.
Struts usually last upwards of 50,000 or 60,000 miles.
But when exactly a shock or strut needs to be replaced is
hard to say. Because the damping characteristics of shocks and
struts deteriorate gradually over time, the decline in ride control
often passes unnoticed. So by the time to think you need new
shocks or struts, it's usually way past the point when they should
have been replaced.
One way to evaluate your need for new shocks or struts is
to consider how your vehicle has been handling and riding lately.
Does it bounce excessively when driving on rough roads or after
hitting a bump? Does the nose dip when braking? Does the body
roll or sway excessively when cornering or driving in crosswinds?
Does the suspension bottom out when backing out of the driveway
or when hauling extra passengers or weight?
A "bounce test" is still a valid means of checking
the dampening ability of shocks and struts. If the suspension
continues to gyrate more than one or two times after rocking and
releasing the bumper or body, your shocks or struts are showing
their age and need to be replaced.
WHY REPLACE THEM?
Weak shocks and struts won't necessarily create a driving
hazards if you continue to drive on them, but there are studies
that show worn shocks increase the distance it takes to stop a
vehicle on a rough surface. Increased body sway due to weak shocks
or struts can also increase the risk of skidding on wet or slick
surfaces.
Worn shocks and struts also increase suspension wear (though
marginally) but can have an effect on tire wear. If the shocks
.
The reason why most people decide to have worn shocks or struts
replaced, however, is to improve overall ride quality. If you're
sick of bouncing and rocking on rough roads, a new set of shocks
or struts will firm up your suspension and restore proper ride
control.
If you're interested in performance handling, you can upgrade
to premium "gas" charged shocks or struts. These are
charged with high pressure nitrogen gas to help minimize foaming
in the hydraulic fluid inside the shock. This lessens "fade"
on rough roads and helps the vehicle maintain better ride control
when cornering.
There are also "heavy-duty" replacement shocks and
struts that have larger diameter pistons than stock. These too,
provide increases resistance for greater control -- but may be
a little too harsh for everyday driving. So some shocks have
special valving or adjustable valving that allows the amount of
resistance to vary.
Another option to consider if you tow a trailer or haul extra
cargo are overload or air-assist shocks. Overload shocks have
a coil spring around them to increase the load carrying capacity
of the suspension (these also tend to ride stiffer than standard
replacement shocks). Air-assist shocks have an adjustable air
bladder that acts like a spring to carry extra weight. With this
type of shock, air can be added on an "as needed" basis
when hauling extra weight.
REPLACEMENT
Shocks and struts are generally replaced in pairs -- though
this isn't absolutely necessary if only one shock or strut is
leaking or has suffered damage at a low mileage.
Shocks are a popular do-it-yourself item on most vehicles
because they're fairly easy to replace. But struts are not.
Most struts require a fair amount of suspension disassembly as
What's more, the wheels must usually
be realigned after replacing a strut. For this reason, you're
probably better off letting a professional replace your struts.
