Upper Control Arm Bushings

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chopface - 15 Jun 2006 04:45 GMT

Hi,

'91 Civic Si (3dr hatchback)
152k miles

I recently took my knuckles off and had new wheel bearings and lower
ball joints pressed in at a shop. I also installed new upper control
arms myself. All work was done on both sides. I have yet to get an
alignment since the work. The car is riding on Tokico dampers and
springs, and has been riding on them since the US presidential election
night in '04. I bought them all in a kit, I don't know the specific
model, but they might be known as the blues. They lowered the car a
bit, and I unfortunately forgot to measure the ride height before I
installed the suspension. I guess about a 3/4" to 1" drop.

The problem I have is that I didn't know how to properly align the
bushings in the upper control arms before I tighted the bolts that hold
them in their unsprung, static position. Now, my rede height varies by
around 3/4" or 18mm from side to side in front. My Helm manual referred
to alignment marks, but I couldn't make any out. If anything, I
thought you might align them with a close to 90 deg. cut in the steel
of the upper arm, and that is what I went for. It compared to the
angle on my old arms, but they were well worn. I knew at the time that
this was probably going to haunt me. Luckily, I think I can probably
take the arms off by only splitting the upper balljoint connection. I
had to cut the old steel reinforcement part that runs betweent the two
bushings in the arm assembly off the old ones sue to corrosion

Am I even diagnosing this correctly? Can these bushings affect ride
height? I inspected other suspension components and everything else
looks good. How would I go about figuring the appropriate geometry to
go for as far as upper control arm pivot angles go? I am thinking of
taking it to a performance/tuner shop to get an opinion. Any ideas?

Thanks,

Mark

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jim beam - 15 Jun 2006 05:39 GMT

> Hi,
>
[quoted text clipped - 23 lines]
> had to cut the old steel reinforcement part that runs betweent the two
> bushings in the arm assembly off the old ones sue to corrosion

while i don't think that piece of steel is vital, i also don't think
it's a good idea to cut it out. if nothing else, it keeps everything in
position until the bushings are firmly bolted to the body.

> Am I even diagnosing this correctly? Can these bushings affect ride
> height?

no. the only thing they really affect is the camber, which might be an
issue if the car's lowered, but ~1" is supposed to be ok without using a
camber kit. definitely should have no effect on ride height.

> I inspected other suspension components and everything else
> looks good. How would I go about figuring the appropriate geometry to
> go for as far as upper control arm pivot angles go?

afaik, the pivot angles are not adjustable - the assembly just bolts
into place. the marks are simply to position the bushings on arm
assembly - for "natural" position [see below].

> I am thinking of
> taking it to a performance/tuner shop to get an opinion. Any ideas?
>
> Thanks,
>
> Mark

if the ride height is different on different sides, i'd check all the
lower bushings for collapse and replace as needed. also check the body
for alignment issues. a slightly different ride height side to side may
not have been so obvious at stock height, but will be more so now.
also, when reassembling the suspension after a job like this, tighten
the bushings only with the full weight of the vehicle on the wheels. if
the bushings are tightened before they're in their "natural" position,
you can have all kinds of alignment and ride behavior issues afterwards.
the bushings can fail prematurely too.

one more thing: i once made a really stupid mistake and put in a rear
lower control arm upside down. it made the ride heights look all odd
but nothing was obviously wrong when up close from under the car so it
took me a while to figure out what was up. just look for that to be sure!

Reply to this Message

chopface - 15 Jun 2006 06:08 GMT

> > Hi,
> >
[quoted text clipped - 27 lines]
> it's a good idea to cut it out. if nothing else, it keeps everything in
> position until the bushings are firmly bolted to the body.

I was trying to describe an existing "cut". Sort of if you look down
the arm assembly as through the axis that the arm pivots on. In the
profile of the steel of the upper arm, on either end of it, there is a
~ 90 deg. stairstep type change in the perimeter of the outer part of
the u-channel steel.

> > Am I even diagnosing this correctly? Can these bushings affect ride
> > height?
>
> no. the only thing they really affect is the camber, which might be an
> issue if the car's lowered, but ~1" is supposed to be ok without using a
> camber kit. definitely should have no effect on ride height.

I forgot about this detail, but I changed my oil tonight, and that was
the catalyst for me discovering this issue, besides the ride being
rough. With the front end jacked up, the wheel well to tire gap was
assymetrical. I measured it with a chunk of wood, but I just checked,
and apparently I only penciled one side, and didn't make a mark when I
campared to the other. I remember it being comparable if not more to
the side to side gap difference with the tires on the ground.

> > I inspected other suspension components and everything else
> > looks good. How would I go about figuring the appropriate geometry to
[quoted text clipped - 3 lines]
> into place. the marks are simply to position the bushings on arm
> assembly - for "natural" position [see below].

The arms I installed did not come with the bolts that compress the arm
to the inner sleeves of the two pivot bushings torqued to
specification. The arms swung freely and one nut was finger-loose.

> > I am thinking of
> > taking it to a performance/tuner shop to get an opinion. Any ideas?
[quoted text clipped - 12 lines]
> you can have all kinds of alignment and ride behavior issues afterwards.
> the bushings can fail prematurely too.

All the other bushings seem okay as far as I can tell. My rear end
isn't at the same height side to side, and that I can deal with because
I know many of the rear bushings are toast. The forks are seated to
the lower ends of the damper well in front. I got the car used, and
don't think it was in an accident, but I wouldn't know.

I don't know if you can really access the pivot bolts with the arms
installed. It looks potentially possible, but there isn't really room
for tools. You'd have to guess the torque on the pivot fasteners that
way. The Helm manual describes an upper ctrl. arm bushing replacement
procedure, and they describe torqueing the pivots off of the car. I
just couldn't really figure out their described alignment marks, and
whether they apply to my non-stock springs and dampers.

> one more thing: i once made a really stupid mistake and put in a rear
> lower control arm upside down. it made the ride heights look all odd
> but nothing was obviously wrong when up close from under the car so it
> took me a while to figure out what was up. just look for that to be sure!

Checked and okay, was already paranoid about that one...

Thanks for the ideas.

Mark

Reply to this Message

jim beam - 15 Jun 2006 14:02 GMT

>>>Hi,
>>>
[quoted text clipped - 44 lines]
> the catalyst for me discovering this issue, besides the ride being
> rough.

rough ride can be a bushing issue, assuming all the mechanicals are
taken care of. tightening with the suspension under full weight is
essential!

> With the front end jacked up, the wheel well to tire gap was
> assymetrical. I measured it with a chunk of wood, but I just checked,
[quoted text clipped - 34 lines]
> isn't at the same height side to side, and that I can deal with because
> I know many of the rear bushings are toast.

that'll make a difference up front.

> The forks are seated to
> the lower ends of the damper well in front. I got the car used, and
[quoted text clipped - 4 lines]
> for tools. You'd have to guess the torque on the pivot fasteners that
> way.

imo, torque is not your most important issue here - i tighten with the
car on the ground, roll it back and forth a couple of feet to make sure
there's no scrub, then do the rear. then, for the front, with the
wheels turned alternately to each lock, you can access all the bolts.

> The Helm manual describes an upper ctrl. arm bushing replacement
> procedure, and they describe torqueing the pivots off of the car.

that's what the alignment marks are for.

> I
> just couldn't really figure out their described alignment marks, and
> whether they apply to my non-stock springs and dampers.

if the ride height has changed, probably not. if you can, do them on
the car.

>>one more thing: i once made a really stupid mistake and put in a rear
>>lower control arm upside down. it made the ride heights look all odd
[quoted text clipped - 6 lines]
>
> Mark

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