Re: Struts?

On 2020-12-03 16:26, Frank wrote:
> 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.
> 

I was told now by two mechanics that they were "leaking".
My old tires show no sign of cupping.  Both had the
the car in the air and checked with a flashlight.
I did not have any reason to believe that they both
were being dishonest.

And the old tires had about 50K miles on them.