Wiper Blade Position

[WVZR-1]

Originally Posted by davekp

I don't think so, they're Trico 20-2. The car is a '90.

Between this document & the FSM you should have no issues providing the ramp(s) are in place.

C4 - Wiper Arms & Blades Adjustments.pdf


Cliff - I'm quite sure the 'ramp' on an early thru '94 is different than that on a '95. I'd think it obvious but I don't have a '95+ C4 to look. The 'stop' also I'd think different.

*********
Through the years GM SPO seemed to have issues for the applications of this 'stop' for the C4. I've never had wiper issues so I've never paid attention. One type or the other should be on all cars.

Wiper arm stop.jpg

[Z51JEFF]

Originally Posted by WVZR-1

Cliff - I'm quite sure the 'ramp' on an early thru '94 is different than that on a '95. I'd think it obvious but I don't have a '95+ C4 to look. The 'stop' also I'd think different.

The ramps are in fact different between atleast 91 and later. I have a set of the later I bought years ago and the design was changed at some point.

[lfalzarano]

I’ve got a 90 also and experienced collisions when light rain and sometimes on high. They claim in the manual that you can adjust them, but I still had ge collisions at times and also the over sweep to the pillars.

My solution was buying new wiper inserts at Chevy. I know the rubber I installed measures 19.5 inches on each wiper. I don’t know what marketing size that is off hand. I kept the original blade holders and stripped out the new rubber blades from their holders and installed the new rubber blades on my original blade holders.

In the CorvetteForum I have read, change both to 19 inch and one post said to change one to 20” and the other was 19”. I’m assuming that we are all using the original blade holders.

You need to fix the collisions at a minimum or risk the wiper blade motor and other plastic parts.

Lou


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[lfalzarano]

BTW - 20 inches is OEM SPEC.


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[DRM500RUBYZR-1]

Many Zr-1's rarely see rain.
I point this out as a means of suggesting that you do not go overboard trying to adjust the wipers.
Absent collision damage or an overzealous windshield replacement technician,
the adjustment by loosening the mechanisms on the cowl is almost always unnecessary.
If the arms have never been off, they then by definition, were placed by the factory in the proper position both individually and in relation to each other.
The MOST common problem we see, is the use of the wrong blade assembly.
A few posts above this one listed suggested replacements.
That list appears dead on, although my notes are back in the office.
You have three variables on blades.
1- length
2- height
3- pin size

20 inch blades are indeed correct

as for height; 90% of the replacement blades are too high to either clear the hood or clear each other at some point in their travel. I your new blade assembly has a higher profile than the original, it will be difficult to impossible to make them work and look visually correct. Save yourself the aggravation, return them if they have a higher profile than the ones on the car.

pin size- pretty obvious; many replacement assemblies have holes for a pin much large than the Corvette accepts.

If you decide to replace or try to adjust the arms themselves, start early in the afternoon, and pay very close attention to the orientation of the installed arms before you remove them. Painters tape and a pencil can save you hours of frustration doing what is often perceived as a "simple ten-minute job".
I ONLY source arm assemblies from the Corvette parts sources, NEVER from parts houses.

Buy the proper parts.
Note existing positions carefully and accurately.
Install new EXACTLY as old ( unless someone before you screwed them up)

When replacing arm assemblies; do only the drivers side first, noting the space between the two with painters tape, and make sure you test it at all speeds and in parked position.
Once the drivers side is perfect, then do the passenger side.
Hope this helps some of you.
Then again, this particular ten minute job is likely responsible for considerable beer consumption.
Marty

[WVZR-1]

Actually GM spec'd an 18" blade for the C4 in EXPORT configuration. I've mentioned to a couple people who have issues to try them. Trico does the Exact Fit in the 18-2 and I believe also the 19-2. Either of these for a 'driver' might be considered a solution for '94 and earlier.

Easier than likely 'adjustments!!! Cheaper too maybe if you bust something attempting the adjustment.

I'm quite sure I used 1" shorter blades on an early truck just because of the 'over-wipe'.

[Mystic ZR-1]

If your wipers hit when operating, could be drag on the windshield.
New blades or cleaning the blades with a silicone base tire cleaner and claying the windshield could solve your problem. You'd be surprised how much crap's on your windshield even though it looks clean...

[secondchance]

I got tired of collisions resulting in scraped hood edge and multiple pressure points of older wiper design and went to 1" shorter Trico beam type blade about 9 years ago. Non - NCRS but fits under the hood edge, works far better and never collided again.

[Paul Workman]

Originally Posted by Mystic ZR-1

*... claying the windshield could solve your problem. You'd be surprised how much crap's on your windshield even though it looks clean...

YES! Good point!

Claybar'ing the WS does remove a lot of crap impregnated in the surface - especially on older glass (i.e., lot of miles).

Also RainEx (sp?) applied and "worked into the glass", will help not only with the sheeting, but the dragging/chattering.

IDK about y'all, but if wiper blades on my other vehicles last more than 6 months, it is the exception. New blades about 2wice a year - MORE is you're like Ami and try to wipe frost off the glass w/ the wipers...

[Riviera]

The AC Delco glass cleaner available at any GM Dealership is amazing and does a fabulous job of cleaning the windshield