Many Corvette owners on the 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'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.
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:
Special thanks to Jeff Kopp (Wholesale parts manager, Superior Chevrolet, 8300 Shawnee Mission Pkwy, Merriam, KS 66202) for taking the time to help me with this project.
Give Jeff a call at 1-800-728-8267 or 913-384-3115 or email him at firstname.lastname@example.org for great prices on GM parts.