C4 Windshield Wiper Arms

Many
Corvette owners on CorvetteForum.com have complained
about
“windshield wiper collisions” and offered various solutions for
curing the problem ranging from replacing the 20″ wiper blades with 18″
units to re-adjusting the wiper drivetrain. None of the
recommended solutions
seem to work in every case. Replacing
the wiper blades proved difficult
because even if you could
find shorter replacement blades that would fit
the wiper arms,
they were often too tall to fit under the hood. Re-adjusting
the wiper drivetrain would sometimes work if the drivetrain was actually
out of adjustment but often the wiper blades still collided
under different
operating conditions (mist, drizzle, monsoons
etc.)

One
CorvetteForum member
said that he saw an article in Corvette Fever magazine
that
suggested replacing the original wiper assemblies on older C4′ with
the wiper assemblies from a 1995-1996 C4. Unfortunately, none of the
Corvette
Forum members could remember which edition of
Corvette Fever contained
the article. After several calls to
Corvette Fever magazine yielded no
answers I contacted Jeff
Kopp (18CarFan on the Corvette Forum) to find
out if he could
shed some light on the subject. He didn’t have any firsthand
experience with this upgrade but he offered to hook me up with the new
parts so I could test this solution.

So,
here dear reader is the end result of all this messing about.
I hope it
helps you cure your Corvette wiper ills.

These
are the original wiper arms and
blades (1984-94). Notice how the blades
are nearly parallel to
one another when parked.

These
are the new wiper arms and blades (1995-96). Notice that the passenger
side arm is bent near the end causing the wiper blade to run
parallel
to the base of the windshield rather than parallel to
the other wiper
blade.

Of
course, since these arms and blades are GM parts they fit in
the tight
space between the windshield and the lip of the hood
as shown below.

Here
the old (left) and
new (right) wiper arm assemblies are shown parallel
to each
other. You can see that the new arm has a much different angle
than the old arm causing the blade to tilt downward.

Here’s
a close-up of the
ends of the old (bottom) and new (top) wiper arms. This
seems
to be the critical change made by GM. The metal portion of the new
wiper blade is shorter even though the rubber blade is the same length
as the original. This reduces the likelihood of wiper
collisions. If a
collision does occur, it’s the rubber tip of
the blade that collides with
the other wiper arm rather than
the metal tip so the collision will be
less jarring. The new
wiper blades are no longer interchangeable. There
is a
separate part number for the left and right.

As
for the construction of the new blades, they appear to much
more rigid
than the older style. The rigidity comes at a price
though, the new blades
are not as sleek as the old. They might
even be considered clunky looking.

In
this side-by-side shot you can see that the old (inner) and new arms
(outer)
are nearly identical. You have to look a little closer
to see the changes
that GM made.

The
new wiper arms have larger pivot
pins at the blade ends. This means that
you cannot re-use your
old wiper blades, they must also be upgraded. I’m
guessing,
but I think this probably reduces the possibility of the wiper
blades flexing and chattering across the windshield.

Two
obvious changes are
the bend in the passenger side wiper arm and the new
location
of the windshield washer nozzle (moved away from the blade end).

The
same view as above but
from the underside of the wiper arms showing the
windshield
washer nozzle relocation.

The
new wiper arms and blades are drop in replacements for the
original assemblies.
And surprisingly, they are less expensive
than the original assemblies.

Here’s
a diagram showing the wiper arm retainer. This retainer must be moved
in the direction of the black arrow in order to remove the wiper arm from
the wiper shaft. You must lift the wiper arm away from the
windshield
until you feel it start to resist, then you can
slide the wiper arm retainer
into the release position. The
wiper arms are ‘keyed’ so they only go
on one way. If the
wiper arm position isn’t satisfactory, you must adjust
the
linkage at the wiper motor.

Here
are the GM part numbers and approximate
costs:

Left
wiper arm: 10288071
…. $13.93
Right wiper arm: 10288072 …. $13.93
Left wiper blade: 22154985 …. $14.45
Right wiper blade:
22155368 …. $14.45

Special
thanks
to Jeff Kopp (Wholesale parts manager, Superior Chevrolet, 8300
Shawnee Mission Pkwy, Merriam, KS 66202) for taking the time to work with
me on this project.