C3 Rear Spring Removal and Installation

Here
is a summary of the removal and installation of a rear spring that
we
did on a 1980 Corvette.

On this job we were removing
the stock steel leaf spring and replacing it
with a TRW style mono leaf
composite/fiberglass rear spring.
The new spring and all of the
hardware needed to attach it were purchased
from Zip Products, through
the Corvette Forum’s Restoration Store.
If you are even tempted to
replace the rear strut rods and / or bushings,
might as well do these
at the same time.

First steps:
Jack the rear of the
car up as high as possible. Don’t forget to put chocks
in front of
the front tires. Always use good quality jack stands when under
the
car.
This job can be performed with hand tools, sockets, ratchets,
wrenches,
c-clamp. An air compressor and air tools help greatly. You
will need to
have a good quality C-Clamp and a torque wrench that has a
10-35 lbs range.
You will also need one other person to help but two
would be great.

The instructions that came with the new spring were
excellent, but here are
my observations and some
photos.

Removal of the original rear spring.
Once the
car is in the air, remove both rear tires, the spare tire and the
spare
tire carrier lid. Removal of these items makes life a lot
easier.

1. Remove the stock heat shield, this is held on with
2 small bolts, pretty
easy.

2. Place a c-clamp on to the
spring near the end where the spring connects
to the rear trailing
arms.

3. Place a jack under the c-clamp and lift the
spring / clamp to relieve
tension on the link between the spring and
the trailing arm. Do not lift
high enough to lift the car, just enough
to raise the end of the spring
slightly.

4. Remove
the cotter pin and castle nut from end link. You will have to
use an
open end wrench on the top of the bolt to keep it from
spinning.

5. SLOWLY and CAREFULLY lower the jack and
the end of the rear spring.

6. Repeat for other
side.

7. Remove the 1 small bolt in the center of the rear
spring mounting pad.
This is the steel plate that sandwiches the rear
spring to the rear end
cover.

8. While you have someone
holding each end of the rear spring, undo the
other 2 bolts holding the
rear spring to the rear end cover. The original
spring is VERY HEAVY –
40 LBS. Slide the spring out of one side of the car.

9. Clean
the mounting location for the rear spring and the spring
mounting
pad.

Install the new rear
spring.

1. Assemble the rear spring pad and spring – do this
under the car. The
order of parts, from the bottom up is: spring
mounting pad, heat shield (the
one that comes with the spring) and then
the spring.

2. Install the new bolts that mount the spring
and pad to the rear end
cover. Don’t forget to use the lock washers,
we did !! We also got to do
this step over.

3. Torque the
bolts per the instructions that came with the spring. Ours
said to
torque all of them at 10, then 20, then 30, then finally 35
lbs.
CAUTION: The rear covers of the earlier C3’s are prone to
breaking at the
mounting “ears”. Be careful.

4. Install
the new mounting links and rubber bushings that came with the
kit into
the rear trailing arm.

5. Carefully jack the end of the spring
upward to meet the end link bolts.
Our spring had a steel end plate and
the instructions told us to jack the
spring up at this
point.

5A. Our spring mounting bolts were further rearward
than the stock spring’s
locations. This caused the end links to lean
backwards to meet the spring.
We had to jack the spring up and have
someone push the end of the spring
forward to get the end links through
the end of the springs.

6. Install the bushings and washers and the
new lock nut and cotter pin.
Once this is done, you can slowly lower
the jack. One side is done, now go
do the other side the same
way.

7. Double-check all of your
work.

8. Re-install the spare tire carrier, the spare tire and
the rear wheels.

Before:

After:

Drive the car for a while and
then come back and adjust the ride height by
tightening or loosening
the lock nuts on the end links.

This job took about 2-3 hours,
with some rest breaks in the middle.

Bryan C. Seery
Team RCRacer
1RCRacer@home.com / BryanSeery@home.com
“‘Everything
but first sucks.’ – Dale Earnhardt”
Heroes shouldn’t have to
die.