Re: Struts?

T <[email protected]> wrote:

> Hi All,
> 
> 2006 Forrester
> ~111K miles
> 
> I was told I need all for new struts.
> 
> I have not noticed ANY bouncing when I go over
> bumps.  Is there a way I can test myself?  On
> other cars I owned, I just pushed down on the
> fender and let go to see if there was any bouncing.
> 
> Many thanks,
> -T

Actually, when I test, I don't just push down once and let bounce up,
but I get the car bouncing up and down and then let go to see if the car
bounces once and then settles.  That just tests large bounces, not for
small ones, and doesn't test behavior over multiple bounces.  That old
trick is only to detect when a strut has catastrophically failed.  It
doesn't detect when the strut is no longer reducing small vibrations as
well, so there's faster wear and greater noise transferred to the body.
If you were to see a slow-mo video of your tires as you drive along that
supposedly flat highway, you'll see them vibrating (small bounces).  If
you were to drive a car with pipes instead of struts, you'd realize how
unflat is that flat road.  Shocks don't just handle the big bounces.
They handle the little bounces as well which affects steering, handling,
and the road noise you hear along with the amount you're vibrating all
the other parts in the car.

You were told.  Well, why did they think the struts were bad?  I can
tell you that you need to replace the evaporator without even looking at
your car, but that doesn't mean I'm correct.  There would be a symptom
they notice that indicates strut replacement: alignment problem,
sagging, shimmy on repeated small bumps affecting steering, tire
shaking, tire cupping, bottoming out on rough roads or at the end of a
driveway, a bouncy ride, body sway or rocking when cornering or getting
hit laterally with high winds, nose dive when braking or rocking or
rolling when changing lanes, clunking noise when the strut is exercised
at angles or knocking noise when the car goes over bumps that sounds to
the driver like something is loose, ride height is wrong (too low) and
means the strut is falling apart internally, a fluid leak due to a
nicked piston rod or old/damaged seal, your car drifts to one side when
braking at high speeds.  Just ask them to explain their diagnosis and
have them show what is wrong.  If they're just going by the residue of a
leak, struts will leak some.  A residual amount on the piston is normal
since no seal is perfect, but it there is a trail of residue down along
the strut body then the strut is bad.

Maybe their just going by age, but that assumes no external damage to
the struts, or excessive wear, but based on average mileage.  If you
don't put many miles on your car per year, struts will last longer.  If
you drive on nice even roads instead of bouncing around on dirt roads or
due to offroading, the struts will last longer.  It'll be pricey.
Struts are replaced in pairs (i.e., both on the same end of the car)
along with inspection and possible replacement of the mounts.  Of
course, if the fronts have gone bad, the rears will follow and at a far
shorter interval than when new, so it's better is to replace all 4 if
you can afford it; else, you'll have another rear strut job before the
next front strut job.  You'll need an alignment after replacing struts.
Did the shop inspect all FOUR struts for leaks, damage, or behavior?  If
they found one, or more, bad struts, did they inspect the rest of the
suspension for accelerated wear?  Saying your car has 111K doesn't say
how the car has been driven or on what type of roads (or lack thereof),
how much the car has been bouncing around, if the typical load inside
the car is heavy (lots of passengers or cargo), if you've been on
repaved roads that could have stone chips flying around to nick the
piston, if you're a 400-pounder which unevenly stresses one side of the
car's suspension, and so on.

If the struts are getting replaced due to age or wear, you should also
get the mounts inspected or replaced.  Worn or damaged mounts also cause
problems.  Because struts are integral to the suspension of the vehicle,
you will need to get an alignment after replacing them.  If one is going
bad, another is also gone bad or going bad, and weak ones can fatigue a
new one faster.  Did they say WHICH strut is bad?  Front ones get more
stress than rear ones due to lunge in braking along with that being the
end that steers.  If you don't trust the opinion of the car shop, why
are you going there?  

I didn't bother to check your vehicle.  Does it have any ride control
systems?  If so, struts are even more important, and uneven behavior
between worn/weak and new struts is going to screw up the ride system.  

The problem with relying on the regular driver of a car to feel if the
struts are okay is the driver will often become accustomed to the
behaviors of a gradually defective strut.  You might be used to the
sway, bumpiness, drift, or other artifacts of bad struts.  Not until the
symptoms get severe will you then notice them.  After getting new
struts, you'll marvel at how much more quick and firm is the handling
and smoother the ride.

Is this shop going to replace the pair of struts on the same end with
Subaru OEM struts, or cheap generics?  I've heard that Subaru struts
last longer than average.  Considering the cost to replace them,
especially if you do all 4, I wouldn't go cheap on the parts.  You'd
only go with different struts if you were unsatisfied with the original
ride, like you'd now prefer a stiffer ride for quicker handling
response, less sway if you like to twerk in traffic, you typically carry
heavy loads, or you are the heavy load lopsided on one side of the car.

I don't see strut replacement listed in the maintenance schedule for
that vehicle.  Subaru only recommends inspection at 15K intervals.
Because of the many variables involved, suspension parts get replaced
when they're worn or break, and that'll be determined by inspection (by
a shop, or by you in your experience in ride and handling).