High speed shimmy

My 99 Civic has been showing it's age recently. For the past 9 months
it has slowly developed a high speed shimmy (60-75mph) that
miraculously disappears occasionally.

I first started noticing it last October, when I changed my summer
wheelset over to my studded winterset. Being a beater winter tireset,
I thought they probably just needed to be balanced. I balanced them
and it seemed to lessen the shudder, but not eliminate it.

Next, I'd never had the car aligned, so I did last November. The
mechanic said that he made some minor adjustments but the car would
still feel the vibrations until the tire tread wore back into it's
normal pattern. Well, they were'nt on long enough for that to
happen...so...

I put my summer wheelset back on in the spring and it still rattled
like hell. I checked out my tie-rods, cv-joints, wheel bearings, did
the old strut test (bouncing on corners and visually inspect for signs
of leakage) and couldn't find anything wrong. Everything seemed pretty
tight. So, I balanced my summer wheelset. No fix.

I recently started noticing my left rear tire cupping in the inside.
The right rear was starting to cup also, just not as severe. The
insides of my fronts were also wearing more than the outsides, just not
cupping. I brought the care to the mechanic and he said that they
couldn't really do anything (alignment or balancing) without new tires
because of the severity of the rear cupping.

I didn't want to throw new tires on, get it aligned, then find out it
was something else after my new set of tires started cupping again; so
I found this group, searched your archives and here I am.

I investigated further. I measured ride height in several places. My
left rear was the lowest by 1/2" to 1". All others were fairly even.
I took a closer look at the shock and strut. They look fine although
worn strut would lower this side as well as cup my tire. It would make
sense. I also, from time to time, throw a lot of weight in the trunk
which doesn't help.

I don't have a lot of cash to throw out and want to get this right, the
first time.

Do you all think it's the strut even though it acts allright (other
than height)?

Would you recommend an alternative strut manufacturer as opposed to
OEM?

Could worn rear struts make my steering wheel shimmy?

Could they make the front's wear uneven, or is this a seperate problem?

Course of action you would take?

Whaddya think?

 

my 98 civic has an intermittent shimmy at 120KPH, tire guy said one of my
wheels (aftermarket) was out of round.

Also, one of my ball joints is ready to be replaced.

t

 

excess toe.

<snip>

ok, on this generation civic, unlike its predecessors, the lower control
arm can be put in upside down leading to lop-sided rear ride height.
look under the car from the rear. both lower control arms should have
the same "slope" to them, with the bushing for the shock being lowest of
the three each side.

if it's not that, check for a broken spring, but usually, that's
accompanied by squeaking/groaning noises.

the strut [technically, it's a shock not a strut - it's non-structural]
doesn't affect ride height. it can affect cupping if it's shot, but on
hondas that's not so common.

kyb are cheaper than oem and imo, just as good.

much more likely it's worn bushings and/or top front wishbone ball
joints. check the tie rods too.

separate problem.

check the rear suspension as described, sort out the worn stuff, replace
the tires, then see where you go from there. cheap tires can cup
regardless of any suspension issue. if you're going to do the work
yourself, buy the helm manual. it's by far the best tool investment
you'll ever make for this vehicle.

 

Thanks Jim,

I checked out the rear suspension as you said and the lower control arm
seems to be installed correctly.

I inspected the spring fairly close and saw some rusting near top and
bottom of coil yet hadn't noticed any failures.

Then, today, when leaving my dipped driveway I heard a "doinngg" sound
from the affected area (Left Rear). It sounded just like a spring
slipping out of place a bit.

Now I'm assuming it's a broken spring causing that rear cupping.
Right?

 

I've had that boing noise from the factory. Dealership never really
satisfied me on that one, but I am at 260000kms, and the car is still driving,
and I don't get cupped tires.

Not to say that in your case its not a problem, but in my case it never has
been.

t

 

if it is a broken spring, yes. you'll have to inspect again with a view
to replacement. oem springs are cheap. they're cheaper still from a
junk yard. check all the bushings while you're under there. the main
trailing arm bushing on that model doesn't last too well. google this
group for replacement part #'s [honda only list the full trailing arm on
parts diagrams] and a recent post by elle on a tool that allows the
bushing to be replaced without dropping the whole suspension.

from this point on, if the spring is ok and the rest of the suspension
is ok [both the rear shocks the same - in case someone fitted the wrong
one at some point], you're going to have to look for body alignment issues.

cupping alone can be a defective tire. i know that doesn't answer your
question about ride height, but tire quality can be an issue. what
brand is it?

 

What do you mean "with a view to replacement"?

I took the wheel off, shined a flashlight on the spring and poked
around the cracking plastic coating on both ends with an awl. The
coating seemed to be peeling (again, only on the ends) because of rust
underneath. I couldn't find any cracks and definately didn't see a
dropped coil.

I guess if these aren't what to look for, then I don't know how else to
inspect springs. Do I have to take the spring out to inspect? If so,
I might as well replace it. (Side question...I should probably replace
the springs in pairs, right?)

Thanks. I'll check these out again. I initially gave these a quick
inspection and didn't see anything of concern. The rubber all seems OK
and there isn't any play when josseled. Any other method of inspection
I should be using?

The tires were inexpensive. Ventus HRII 17". Thing is, after
inspecting my winter tire set (nokian hakkapellittas) these were very
slightly unevenly worn. I might, very slightly, be able to detect a
bit of cupping on these also.

Man. I really hope it's not a body alignment issue.

 

OK It's most likely not a broken spring. I measured the distance from
both spring seats and compared. The distance is almost exact (within
1mm).

The summer tires have approximately 33K miles on them. They are
inexpensive tires and I hope that they are to blame for all of this.

My winter tires have about 35K miles on them. Now that I'm seeing the
cupping on the summer tires, I inspected the winter tires more thorough
and think I see very slight cupping. It might just be the power of
suggestion though. They are loud regardless because they are
large-lugged and studded.

Maybe I'll take some pictures and provide a link so you can all see
what I'm talking about.

 

OK, newest update:

I recently noticed a pretty serious negative camber on my rear wheels.
The most affected tire has the most negative camber. I took a 2ft
level out for some quick and dirty estimates and used it to determine
the severity of the camber.

I inspected, once again, the bushings, bearings, ball joints, tie rods,
steering, etc. and all I can find is some minor dry cracking in the
lower trailing arm bushing.

The rear wheels on this Civic don't have any camber adjustments?
Right? Nothing seems bent. I just don't know.

All I can imagine, and other have said it isn't possible, is that the
17" aluminum wheels, with lo-profile tires are to blame. They seem the
same overall height...

Anybody else have this issue without having lowered the car?

 

no, no adjustments. if it's out of camber, either something's bent, a
bushing has gone, or as you've said before, the ride height is somehow
defective so the wheel is seated too high up in the wheel well. that's
your #1 priority.

if the wheels are all the same size...

yes, but only when a rear control arm was in upside down. all other
instances i've seen were crash damage or failed springs.

before, you mentioned posting some pics - at this stage, that would be
really helpful.