Re: Struts?

On 12/3/2020 3:36 PM, VanguardLH wrote:
> 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).
> 

Heard leaking was a sure sign but clipped this from the internet:

Badly cupped tires and/or noticeable tire shaking, wheel shimmy or 
vibration after hitting a bump

Suspension bottoming on rough roads or when backing out of a driveway.

A bouncy ride.

Body sway or rocking when cornering or ­driving in strong crosswinds.

Nose dive when braking hard.

Fluid leaking from a strut or shock.