Front Suspension Rebuild Lessons Learned
Front Suspension Rebuild Lessons Learned
Front Suspension Rebuild Lessons Learned
Following
are my observations and lessons learned
from rebuilding the front end
of my 1980 Corvette.
For all
the years I’ve
subscribed to Corvette Fever and Vette, there have been
numerous ”how to” articles on front suspensions, but no one ever seem
to address the ”speedbumps” that I encountered. Since the
above sources,
Haynes, and the Factory Manual provide good
information on how to rebuild
the front end of our C3’s, I
thought I’d limit my discussion to my personal
experiences
and lessons learned the hard way.
The
Background
I was able to do the
job with relatively few special tools. Although I was a
mechanic for 8
years back in the 70’s and still have all my
tools, they are just your
garden variety collection of sockets
and combination wrenches. Flare wrenches
come in handy for
compression fittings, although open-end wrenches can
be used
if you’re careful. A torque wrench is a necessity, as is a pickle
fork. Spring compressors can be rented for low cost (or for free – see
below).
First
off, I had the luxury of time. My Vette is not a daily driver, so I could
work on it when I *wanted*; this is supposed to be fun, right?
I started
the last week of December 1999, and wrapped it up
the first week of March
2000.
I knew
I had front end work to do when I
test-drove the car – but I purchased
a project specifically to
help cleanse my mind after sitting all day at
a desk job. At
least I approached it from an ”educated customer” viewpoint.
There
was considerable slop in the
front end. When I turned the wheel, it felt
like one wheel
went left, and the other wanted to go right. Following
the
test drive, I noticed right off the bat that the rag joint was totally
shot – the metal safety pegs were banging on their safety
stops. The idler
arm was also toasted – it had about 1 full
inch of vertical play. I noticed
that one side of the sway bar
end links was missing. Not the bushings
– the entire link! It
was a different car just by replacing the shocks,
idler arm,
rag joint, and sway bar links, all done soon after I made my
purchase.
In addition
to the rag
joint and idler arm, after further examination I found that
the p/s cylinder bushings at the frame rail bracket were falling apart,
and the support bracket at the frame had 2 of the 4 mounting
bolts loose.
I obtained new bushings from Dr. Rebuild for $4.
However,
it still wasn’t tight.
After completing several other projects and finally
getting it
on the road in December 1998, I spent a year driving it and
making notes. The suspension still needed more work. I compared the Vette
to my Porsche 944 which I sold in order to get the Vette. The
944 handled
like it was on rails, and I felt that the Vette
should as well. Yet, although
all was fine on the straight and
level, any bumps would get scary *real*
quick…
I knew
the lower control arm
bushings were shot – if they weren’t metal-to-metal,
they
were darn close! So, in setting out to replace those, I figured I’d
do some other stuff as well, like the balljoints. I also
noticed that
the right side drooped about 1/2” lower than
the left, so I decided to
get new springs as well. I did not
replace the tie-rod ends – all 4 appeared
very tight, and I
figured that if I had to go back and re-do them later,
it
wasn’t something I’d have to rip out the entire front end to do.
Getting
Started – The joy of removing
springs
Once up on sturdy jackstands and wheel
chocks, I began by removing the
wheels and all brake-related
material – the caliper support, dust shield,
etc. I left the
calipers attached to the hydraulic lines and used coat
hangers
to suspend them from the frame. I also removed the steering knuckles
from the spindle, but left them attatched to the tie-rod ends. I removed
the springs by placing my sturdy 3-ton floor jack underneath
the lower
control arm spring pocket (after removing the
shocks, of course), and,
after loosening but not removing the
upper balljoint stud nut, used a
pickle fork to separate the
spindle from the upper ballljoint. Removing
the balljoint stud
nut, I VERY slowly released pressure, and the arm came
down
with the spring very nicely, with no pops or signs of impending danger.
If you are not comfortable doing this, take proper steps to
ensure that
the spring cannot escape. When compressed, the
spring is under hundreds
of pounds of pressure. If it pops
loose, it can easily maim or kill if
you get in its way. Some
folks recommend using a spring compressor in
addition to the
jack. Others recommend using a stout chain wrapped through
the
spring and chained to the frame to ensure that the spring remains
captive. I did NOT stand anywhere near the suspension (I had the handle
of the jack pointing to the front of the car), and moved the
other car
out of the garage – just in case. Once the tension
was off, it was a simple
matter to push the lower arm the rest
of the way and remove the spring.
The left
lower arm came out very easily. The
right side, however, was a slightly
greater challenge. The
transmission cooler lines run directly over the
head of the
rear attachment bolt, and, due to the ”channel” nature of
the frame at that point, made it impossible to get a wrench on it. At
this point, the cooler lines were still attached to the radiator. I was
able to remove the bolt holding the cooler line support
bracket from the
frame and bend them out of the way enough to
get a wrench on the head
– but it was a pain because the lines
still had quite a bit of tension
trying to get back to their
original location. The wrench slipped off
many times in the
course of removing the nut.
Supplier
& Parts Selection
As far as supplier
selection, I decided on Energy Suspension poly bushings (control arm,
sway bar bushings & end links) based on recommendations from other forum
members. Energy Suspension only sells through parts houses – I
got mine
for ~$54 from Jegs.
Regarding
springs, I considered getting Moog
springs from a local auto supply as
has been suggested on the
Forum, but, as also noted, you usually don’t
know what
spring rates or what number of coils you’re going to get aside
from specifying the year, engine, and options. Maybe you do – I just
didn’t
get the answers *I* was looking for, so I didn’t
dig further. I went with
Vette Brakes 460lb GT 7-coil
(shorter) springs, $79. Also went with their
balljoints, since
their price was comparable to everyone else. ~$25-$29
each.
New upper and lower bumper stops were from Dr. Rebuild, $14.
If you
want to stay with rubber
bushings you may only need the lowers; visually
check the
upper bushings and balljoints – the lowers are usually shot,
due to greater stresses. Uppers are *usually* pristine – both bushings
and balljoints, although I have seen uppers destroyed as well.
The condition
of the uppers can usually give an indication of
the use or maintenance
of the car. If they’re torn up, your
car may have been raced or driven
hard. If they’re very
oily or rotted out, you should make sure that other
maintenance tasks are considered while you have everything apart, for
easy access. On my car, I noticed that the right front bushing retainer
was gone – as in totally missing. Yet, the bushing itself
appeared like-new.
Of course, since you’re ripping
everything out as well, you might as well
do it once and get
it over with.
The
Upper Arms & Radiator
Regarding removal of
the
upper arms, on my 1980 the radiator shroud is a huge, one-piece monster.
You can remove the cross shaft-to-frame bolts with the shroud
in place,
but there’s no way you’re going to be able to
slide the control arm off
the end of the frame bolts. Either
pound out the bolts (Bubba) or start
removing stuff. I could
get the left upper arm out simply by removing
the shroud
retention bolts and moving the shroud slightly. The right side,
however, still didn’t have enough room. I had to remove the radiator to
provide enough maneuvering room for the shroud to allow
removal of the
arm. I also ended up removing the a/c
compressor (didn’t have to break
the lines – just removed
the mount to allow it to be moved around as needed).
A side
benefit to this approach is
that anything related to the radiator can
be taken care of at
the same time. My upper hose neck had a minor, but
annoying
leak. While at the shop, I figured that it could be boiled out
at that time as well. Also, part of the radiator support seals were gone,
so I used that as an opportunity to get a new seal kit from
Dr. Rebuild;
$30. I suppose that if I loosened the radiator
support that I could have
gained enough working room without
having to remove the radiator, but
I’ve heard rumors that
unless you break the a/c condensor lines you don’t
gain
that much room. Since I had the intake ducts and shroud mounts removed,
it was relatively simple to remove the radiator, but this step
did require
an extra set of hands. The hood does not have to
be removed for this task.
While
removing the radiator, I noticed seepage
around the rubber transmission
cooling hoses going from the
frame to the radiator. You can’t use any
old hose here. ATF
usually causes ordinary rubber to swell and deteriorate
over
time (which is also why you don’t want to use it as PS fluid, by
the way…). I ordered replacement hose from Dr. Rebuild ($10). When it
arrived, though, it was just a section of ”Dayton” brand
”ATF Cooler”
hose. In retrospect, I suppose that any place
that installs auxilliary
tranny coolers (like an RV or trailer
shop) would have some of this hose
available. Lesson learned,
I guess.
Check
the PS Hoses
While You’re in There
When you’ve got everything
out of the car, you might want to check the PS hoses carefully, since
the lower control arms block a few of the viewing angles. Mine were soaked
and hidden under 1/4” of crud. If you’re going to replace
’em, there’s
a lot more room available to see and work
once the left lower control
arm is out of the way. Degrease
and Simple Green the PS control valve
area, and recheck after
a day or so to see if any new seepage occurrs.
The
valve-to-cylinder hoses on mine were perfect, but the pump-to-valve
hoses were both shot. At first, I thought I only needed one – the pressure
hose, due to an obvious split in the outer hose. Since I was
ordering
other items at the time, I used Dr. Rebuild ($22),
although other suppliers
also stock the part for similar
prices. Once the PS area was cleaned up,
it appeared the
return hose was leaking as well, but I thought it was
just
from a loose hose clamp at the pump. Only after I removed the pressure
hose and started to tighten the hose clamp on the return hose
did I notice
that the upper part of the hose was hard and
brittle with hairline cracks
in it, necessitating a
replacement. Surprisingly, GM still stocks the
part under the
original part number shown in the assembly manual; $17.85.
I
didn’t think to check them beforehand on the pressure hose, but given
the availability of the return hose, I would assume the
pressure hose
would also be available. Avoid discount parts
here. The locally available
return hoses were nothing more
than a piece of cut hose (O’Reilly) or
a piece of hose with
a separate compression fitting that must be attached
to the
hose with a supplied hose clamp. Unfortunately, the metal tubing
attached to the fitting was bent to a ”generic” position that looked
like
it would have interfered with other components of the PS
hoses and valve.
Go with the General.
Rivet
Removal
Getting the rivets
out of the lower control arms was a royal pain in the butt.
I’ve drilled
out the rivets holding the rear hub to the
rotors, and that was a piece
of cake compared to the lower
balljoints. The heads are rounded, so you
can’t easily
drill ’em out. Forum members generally describe two preferred
methods for rivet removal: either grind off the heads and drive out the
rivets, or chisel off the heads, then drive out the rivets. I
ground off
the heads and started beating. They wouldn’t
budge. Got a chisel – thought
that maybe I hadn’t ground
far enough, but didn’t want to go further for
fear of
ruining the arms. Got a bit more off, but *still* couldn’t drive
out the rivet studs. Center punched the studs and drilled out the rivets.
They *still* didn’t want to pound out! Drilled some more,
and finally
got them to move in enough that, with my trusty
2’ x 1/2” Snap-On crowbar,
er, ah, I mean screwdriver, I
was able to pry them out. I never did succeed
in actually
getting any of the rivets out of the lower control arm balljoint
castings. In retrospect, I *think* that I was drilling/driving at a wrong
angle. From the top of the arm, I thought I was at the right
angle relative
to the balljoint casting. Only after the joints
were out of the arm did
it look like they might be at an
improper angle. You might want to double-check
this point.
The upper
rivets, by comparison,
were a breeze – 20 minutes total for all 6. Chiseled
off the
heads, and a drift punch knocked ’em right out.
Bushing
Decisions
Next, I had to
decide
whether to remove the bushings myself or to pay
someone. I quickly discovered
that very few places will do it
right. A local parts/machine shop that
does more than just
resurface rotors wanted $12.50 per arm to r&r the
bushings –
but would have to ship them out to their centralized facility.
I found a place with a press that said they do them all the time. However,
when I picked up the arms, I found out they used an air-chisel
to get
them out! ($40) I could have done that myself and saved
the $40 had I
known that to begin with!
I purposely
chose to just remove the bushings,
*then* clean up / sandblast the bare
arms and repaint before
the new bushings were installed. After all, I
didn’t want
sand fouling my new bushings! I used a putty knife and screwdriver
to remove most of the heavy crud, followed by a liberal application of
engine degreaser. Some folks have taken all 4 arms to the
local car wash
to use the degreaser / high-pressure washer. I
have found over time that
most degreasers do a good job of
removing the grime, but usually leave
a thin oily film. As a
result, I follow up the degreasing step with lots
of Simple
Green and a toothbrush that gets rid of that last bit of residue.
Since I’m not into NCRS correctness, I sandblasted my arms, then
followed
up with a few coats of underhood black spray paint.
After
another search to try and
find a ”credible” shop, I found a place that,
once again,
”did them all the time”. This time, at least I saw evidence
that their press had been used, accompanied by some old bushings sitting
nearby that were obviously pressed-out, not chiseled. After
paying $80
(!) to reinstall, I noticed that two of the lower
bushings (1 per arm)
had the outer shell crimped against the
inner sleeve. ”Oh, that won’t
affect handling at all!”
was the reply. <*sigh*> Once home, I had to remove
the poly
part and use pliers to bend out the shell. Yeah, I could have
bitched all I wanted, but that still didn’t fix the problem at hand.
I suggest
that if you don’t
install the bushings yourself, and if you use poly,
use the
supplied grease *after* you get them back from the shop – the
bushings will slide right out with a little assistance, unless the shaft
is binding, meaning that *someone* bent the control arm. (At
least I measured
mine before and after – no damage,
fortunately). I greased mine beforehand.
Evidently, however,
during installation it seemed like much got wiped
off. Had to
re-grease mine after pressing.
One Forum
member (couldn’t find the message
via search, though, ) mentioned that
he went out and bought a
20-ton press from Harbor Freight. Some of you
questioned his
sanity. After going through what I went through, I think
it
would probably be a good investment. Of course, you have to realize
that I’m anal about a lot of things. If instructions say to do
something
a certain way, I figure that there’s good
rationale or experience for
doing it that way. That’s why I
had a problem not being able to torque
my r/rear upper control
arm bushing (see below) – I wasn’t about to ”just
put a
wrench on it and turn as hard as you can!” I’m not saying there’s
*no* Bubba in me, but I usually fret about the details more
than some
folks do. (I also read *every* word of a contract
before I sign it…Yes,
I’m an engineer…) Anyway,
checking Harbor Freight’s website, the 20-ton
is going for
$199, a 12-ton is $119, and a 6-ton is $69. Given that I
”beat” my U-joints out by hand two years ago, and that I’ll
probably continue
to find uses for it, I may spring for one as
well. Maybe at least the
12-tonner. In retrospect, with the
time I spent driving around, the mental
anguish, and my own
rework, it would have been worth every penny to do
it
right.
If you
choose poly
bushings, I recommend you torque all bushings before you put
weight on wheels, just for ease of access. The poly bushings are free
to rotate in the outer shells unlike rubber bushings which are physically
bonded to the shells. You migh also consider using a drop of
blue Loctite
(the kind that allows removal with handtools) on
the threads to avoid
loosing a bushing retainer. Another
suggestion is to torque the upper
bushings before reinstalling
the arms in the car. On my ’80, at least,
it’s near
impossible to get to the right rear bushing retainer with the
a/c compressor (the lines are in the way even if the compressor is
unbolted),
A.I.R. piping at the manifold, plus other ancillary
”stuff”. You can get
a wrench on it, but you have no space
for swing radius – not even 1 click’s
worth. I ended up
rigging a bunch of extensions / reducers / etc. and
torquing
that one bushing from underneath the car. Even with my Rube Goldberg
affair, I had to first ”drop” the torque wrench into position from the
top, then go underneath to actually turn it on that one
bushing.
Reinstalling
the Coil
Springs
Reinstalling the coil
springs was
another adventure. Two camps here: Use a spring compressor
or
use a floor jack. Since I went with Vette Brakes’ shorter 7-coil vs
10-coil springs, I assumed installation would be easier. First
trial runs
without the jack looked like there might be a
problem, since the center
of the spring would bind on the
lower lip of the upper spring pocket.
I decided to stop right
there and be safe. Checking with the local AutoZone,
I was
able to obtain a free loaner spring compressor, but that still did
not solve my problems. I mounted the compressor to the spring with the
hex end pointing down, so that I could loosen the compressor
once everything
was secured. Unfortunately, I had the
compressor too far up the spring
such that there was too much
threaded rod protruding above the upper coil
of the spring,
and it would not fit into the upper pocket. After several
tries, I could not get it to a good spot that would allow it to fit into
the upper pocket without having the compressor ”arms” bind
in the lower
pocket.
Next,
I recalled several members suggesting that
it works well if you install
the compressor from the engine
compartment, through the upper shock mounting
hole. To do
this, you remove the threaded compressor arm, allowing the
free-spinning arm to be removed and reversed such that the larger flat
spot of the arm rests on the upper shock mount. The threaded
arm is then
reinstalled onto the rod from underneath and the
coil spring is put into
position. Once I tightened the
compressor, however, the lower part of
the spring drifted out
over the top of the lower control arm balljoint.
I could not
push the spring into position without feeling like I might
cause it to pop loose and do some physical damage (to me, that is!). I
loosened the compressor a bit, which allowed me to safely push
it in far
enough to raise the jack. Looking back, I probably
had the spring too
tight, which over-emphasized the drift. As
I was slowly raising the jack,
it appeared that the spring
would once again bind on the lower lip of
the upper spring
pocket, but as I continued jacking, it slowly slid into
place.
In retrospect,
I was
trying to reinstall the springs in the reverse order of removal.
I had the arms mounted in the car, and was trying to raise the arm with
the jack under the balljoint end. Other forum members
suggested (after
I already had the springs reinstalled –
rats!) that after installing the
upper control arms, you
should mount both upper and lower balljoints to
the spindle,
and place the jack under the rear of the lower control arm
(i.e., where it mounts to the chassis). Although that seems like it might
work better, I would have serious concerns laying underneath
the car trying
to get the cross-shaft bolts in place with only
a floor jack keeping the
lower arm and spring in place.
Finishing
Up
Once the springs are
installed and
the balljoints torqued properly, the remainder of the installation
should take an hour to an hour and a half. This would include
reinstallation
of the dust shields, steering knuckles, and
calipers. I also used this
opportunity to clean and repack the
frontwheel bearings and install new
grease seals.
Time,
Cost, and
Suggestions
Other minor expenditures
included
new antifreeze for the radiator and a set of camber adjustment
shims from Dr. Rebuild ($14), and a set of front disk pads (not really
needed, but I did the rears last year, so just to be anal
about it….).
I also replaced all of the upper control arm
bushing retainers, since
one was missing and I didn’t want
one to look different from the others
(sheesh!).
So that’s
about it. I’ve put
about 40 hours into the front suspension. Lots of time
spent
cleaning and re-cleaning, blasting, painting, etc. I actually had
the lower arms, sway bar, and springs out within an hour and a half of
starting. About another hour and a half fighting and cussing
the radiator
shroud and upper arms. Some weekends were too
cold, even in the garage
in Texas. (Hey, it’s supposed to
be FUN, right?!?). I waited until I had
it all apart before I
even ordered parts just so I could avoid missing
things I
hadn’t counted on. Starting and stopping over two months, with
the associated cleaning of tools, etc. adds quite a bit of time as well.
Most activities were done on the weekends. Some cleaning of
the frame,
PS area, etc. was done an hour at a time during the
week.
Oh yeah
– final
suggestions: Latex gloves. Places like Sam’s Club have packages
of 200 for roughly $6. They are well worth the cost to save your skin,
if, like mine, your hands get chapped and split open in the
dry winter
months. The gloves also make it easy when, covered
with crud, you suddenly
realize you want to open up the shop
manual to recheck that torque spec.
Just peel off the gloves
and keep the manual clean. Also, whereas a sprayer
bottle of
Simple Green is about $4.50, Sam’s also sells 160oz (5 qts!)
for about the same price. Great stuff.
Good
luck and take pride in your work. Nothing
beats saying to your friends
– ”Yeah, I did it myself!”
antifreeze | 8.00 | local |
ball joints (4) |
99.80 | VB&P |
bushing out labor |
40.00 | local |
bushing in labor |
80.00 | local |
bushing retainer (upr) |
10.40 | Dr. Rebuild |
bushing ret. bolts |
4.40 | Dr. Rebuild |
camber shims |
14.00 | Dr. Rebuild |
coil springs |
79.95 | VB&P |
control arm bumpers |
15.75 | Dr. Rebuild |
control arm bushings |
54.99 | Energy Suspensions/JEGS |
control arm shields |
12.00 | Dr. Rebuild |
front disk pads |
10.81 | local |
frt sway bar link kit |
10.55 | Mid America Designs |
grease seals (2) |
7.77 | local |
idler arm |
43.88 | local |
poly link bushings |
11.69 | Energy Suspension/JEGS |
p/s fluid |
1.92 | local |
p/s pressure hose |
22.00 | Dr. Rebuild |
p/s return hose |
17.85 | local GM dealer |
radiator cap |
6.76 |
local |
radiator repair |
52.50 | local |
radiator seal kit |
30.00 | Dr. Rebuild |
rag joint |
50.00 | Zip Products (GM sells also) |
shocks (2) delco gas |
49.50 | Mid America Designs |
steering cyl bushing |
4.00 | Dr. Rebuild |
sway bar bushings |
14.69 | Energy Suspension/JEGS |
trans cooler hose |
9.80 | Dr. Rebuild |
upper rad. cushion |
5.50 | Dr. Rebuild |
Total | 768.41 | (local tax & shipping not included) |
(shocks, rag joint, idler arm, and sway bar link kit done Fall 1997) |