Noland's C-1 Tips
Posted 7-3-04:
Well, I'm a little late getting in on this
discussion, but here goes. There are several unique areas of the C1 Corvette
suspension system, which traces its heritage back to the 1949 Chevrolet
passenger cars. While the front ends are not identical, they are very similar.
There are two parts that must be checked carefully
for safety's sake. These are the third arm support and the third arm. The
support mounts under the center of the front crossmember with bolts, and the
arm itself mounts on a large bearing in the rear of the support. These are
cast iron pieces, and are subject to breakage. It is common to jack up the
front end of the car using the center support, but this can cause a failure of
the support, which breaks just ahead of the big support bearing. First, one
should never, ever jack up the Corvette using the third arm
support; use the lower A arm instead. Always examine the third arm support for
signs of cracking. The third arm itself should also be examined because they may
crack, but such events are fairly rare. If the third arm support breaks, it
will be at low speed, like backing the car out of the garage, and turning to
line it up with a driveway. It will be obvious because each front tire will go
its own way, and steering the car is impossible. I estimate that 10 to 15
percent of C1s on the road today have cracked third arm supports, while less
then one percent have cracked third arms. It's not hard to check the third arm
support: just clean off the area forward of the big support bearing, and check
both sides for surface cracks.
There are two ways to cure this problem. An
experienced welder can weld cast iron and make it better than new. If you get
a replacement (reproductions were available many years ago), make sure the
casting numbers match. There were three different third arm supports and third
arms from 1953 through 1962, and you must have an exact replacement.
The original front wheel bearings were ball
bearings. Apparently GM didn't want to pay a royalty for using the improved
tapered roller bearings, but they finally changed to tapered roller bearings
beginning with the 1963 Corvette. In my opinion, changing to tapered rollers
is a definite improvement in handling.
GM sells four levels of shocks. Use the cheapest
ones for 1953 to '62 Corvettes: they're oil filled. The others are gas shocks,
and they're too harsh for the old Corvettes.
Overhaul the steering box. The gears are case
hardened, which means just on the surface. Once they wear through the hardened
surface, the gears wear quickly, and you will replace them very soon anyway.
Replacement front coil springs are often too
stiff, and the car sits high. After installing the "proper"
replacement, the front end of my '53 sat too high. There is some settling to
be expected, but this was too, too much. I finally found a pair NOS springs;
while the price was high, they solved the height problem. Fortunately, they
were easy to change.
The use of needle bearings in place of the king
pin sounds intriguing. This might be an improvement, too.
The front suspension has several cross shafts and
tie rod ends. In a car that's over 40 years old, all of these should be
replaced. This is an area of concern to me. Parts made overseas are a
less-than-perfect quality. They cost about 15% less than the American made
parts, but the US made stuff is much better. No matter where you buy parts,
there's usually a choice; don't cut corners here.
The last area where C1 handling can be improved is
through the use of radial ply tires. There's even a radial white wall
available in a 6.70 X 15 size.
If you do all of these improvements, your C1 will
drive as well as my restored '53.
Good Luck, Noland Adams
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