Wiper Door Alignment (1970)

[Mark Stavropoulos]

I can't seem to get my wiper door aligned. The end closest to the windshield sticks up too high, higher than the forward edge. There is no mechanical interference on the fender sides and the stop screw is a good 3/8" from bottoming out. It appears as if the entire assembly needs to be moved toward the windshield. I saw in the AIM a note indicating "shim as required". What does one use for shims? I assume they mean shim the oblong retainers/screws.

Thanks, Mark

[Dave S.]

Re: Wiper Door Alignment (1970)

Mark, My low mileage unrestored 71 has rusted flat washers under the the grille ahead of the wiper door. They are located at some of the phillips screws and the washers have masking tape residue like the body shims. Apparently the washers were held in place w/ the tape prior to installation of the grille and screws.

[Jack H.]

Re: Wiper Door Alignment (1970)

Shim as required note in the AIM points to the wiper door to firewall geometry and shims were used beneath the firewall mounting brackets on an as req'd basis. Effectively, this shifted the wiper door assy fore and aft w.r.t. the gaps between the hood and the windshield reveal moulding. The securing bolts inside the firewall also have minor 'up/down' adjustment, but in order to effect this you need to release ALL of the the firewall mount bolts and this is hard, if not impossible, once the wiper door frame has been installed (distributor, ignition shielding, Etc. get in your way afterwards).

Often, what appear to be original cars appear with washers and/or shims installed between the wiper door grille and the wiper door grille mounts. In my opinion, this is not factory original (I could be wrong) but came about because somebody downstream from the factory did an R&R (remove and replace) operation on the wiper door frame, put it back together without properly shimming the frame to the firewall, discovered the error AFTER they'd installed the wiper door frame and 'jury rigged' at the frame to grille interface to compensate and avoid having to re-do the frame installation from scratch....

The Chassis Service Manual for you car has a section dedicated to the Corvette wiper door and it shows/documents what adjustments do what. I guarantee you proper alignment IS possible if original parts have not been torqued out of tolerance and you're willing to take the time to study, tweak, and iterate on the installation process....

[Dave S.]

Re: Wiper Door Alignment (1970)

You can't jury rig the installation of the wiper door grille as the coutour of the grille is what it is. Shims were put under the grille to prevent putting undue pressure on the grille when tightening the screws and to provide proper alignment. Both my 70 and 71 low mileage cars have rusted steel washers in selective locations.

[Michael Hampson]

Re: Wiper Door Alignment (1970)

Dave,

When I re-installed my wiper door assembly on my '68, I had a similar problem. With the grill flush with the fender top, the rear (windshield) end of the door was much to low. The whole assembly needed to move towards the rear of the car about 1/8" and be shimmed to be level front to back. I also saw the "shim as required" AIM notation, but even with wide fender washers between the wiper door mounts (where the studs come out) and the fiberglass panel, the fiberglass was significantly weakened and the door assembly was not secure. There is a large amount of stability added to the fiberglass by the large surface area of the door mounting bracket. With the smaller surface area of washers, the fiberglass area flexed unacceptably.

I figured I had two choices.

One was to machine shims for each of the mounting locations. These shims would need to be a) made with the same "footprint" of the mounting bracket for support purposes, and b) be tapered from top to bottom to make the door level front to back. I figured that this would require too much trial and error on the tapering process.

The second choice (that I chose) was to install 1/16" steel plates inside the wiper door area to shore up each of the mounting locations. I made the plates as large as possible to fit in each of the mounting recesses, for maximum strength. I machined the oblong mounting holes in the plates, fiberglassed them in and painted them black to match the rest of the area. At this point, I could "shim as necessary" the mounting brackets without fear of weakening the area at all.

I don't like introducing non-originality in my car, but this is totally invisible and greatly adds to the strength of this area.

-Michael

-Michael