C1 Corvette Windshield Post Problems and Fixes

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Many of our 1956 to 1962 Corvette customers report a noticeable vibration or rocking at the base of their windshield. More frequently than not, the windshield mounting posts have snapped off. Over the years, many of these posts may have had questionable repair work, with shims, metal strips, and welding used to varying degrees of success. In the mid-1980s, Corvette Central developed a permanent fix for this issue by designing a machining operation that allows the installation of steel tabs that are much more resilient than the originals. Follow along as we describe the post variations, breaks, and solutions to windshield posts.

 

There are two variations of windshield frame posts. The 1956-58 version has a square notch relief for the doorpost with the upper window stop (Corvette Central part number 281009). The 1959-62 version has an angled notch to allow for the later style door weatherstrip, which features a built-in stop and continues over the doorpost (Corvette Central part number 631010). 

 

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Warning: It is crucial to have the doorposts match the frame post.

Grouping combined with yearsAbove: 1956-58 and 1959-61 doorposts. Unlike these, very late 1961 and 1962 doorposts had a smooth surface in the weatherstrip mounting area.

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We speculate that some of our C1 customers have not seen a windshield post with an intact tab. Pictured is one on the right, with a modified version on the left.

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This image is typical of the clean break we see on most posts. It is common to see one or two 5/16″ SAE washers on the rear stud. They are being used as a shim to force the upper part of the frame forward. It’s likely that the washers broke the tabs.

 

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Pictured are some examples of broken tabs. From left to right:

Left: Obviously, this post was in use for years with a broken tab.

Middle: An attempted weld. Welds like these damage the post and compromise the repair.

Right: A clean break. Note: the dark material is an indication of an older fracture.

 

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These are right-hand posts. There are many more right-hand posts that are intact. The reason for this is that GM sold them (under part number 3762680) for many years after the left-hand versions had long since disappeared.

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 Above: We have a box of left and right-hand posts. Contact us if you need a pair.

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Here is what our windshield post-machining station looks like on Monday morning. If you look closely, you can see the posts already have helicoils installed (visible by their reddish tint). We run the posts every Monday for shipment on Tuesday.

 

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Pictured above: installing helicoils.

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This machine, called a Bridgeport, has had this Corvette Central designed and developed fixture since 1983.

 

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The fixture’s design pivots from right to left by removing an Allen bolt (seen in the foreground) and swinging it to a second location. In this photo, the mounting hole for the tab is being tapped. This fixture works the same on 1953-55 posts.

 

 

 

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When installing the studs, you will notice the helicoil threads are tight. The reason is, when initially installed, the pictured stud sets the helicoil in place.

 

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This image shows the mounting of the new steel tab. Our CNC department machined these tabs in three separate processes from a 1/4″ thick laser cut blank. Corvette Central uses approximately 250 to 300 tabs (pictured below) per year.

 

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Our windshield post-repair service is part number 411040 (available for left and right side applications). The tab mounting screw will protrude a bit after tab installation. The exposed screw should be ground away (a 4″ cut-off wheel disk works well for this task).

19 thoughts to “C1 Corvette Windshield Post Problems and Fixes”

  1. I live in Australia, and need to have my posts repaired but I think the postage to you is going to be extremely high due to weight (and turnaround will be very long) so was wondering if you would consider sending me a kit so I can get a local machinist in Brisbane to do the conversion for me? Corvette Forum members suggested I contact you.

    Regards
    Mick Stumpf

    P.S. If you are unable to send me the kit are you able to fast track my posts if I send them to you otherwise It might be 3+ months before I see them again. There is also the added risk of sending and receiving OS and the package getting lost on either leg of the journey. Thanks for your time

    1. We do not sell the parts for our windshield post repairs. As far as shipping, please call us at (800)345-4122 and speak to Customer Service regarding your options.

  2. I have a 60 Vette and both tabs are broken. As far as II can tell, the windshield weatherstripping has never been changed. Decided to change the weatherstripping out. That iis when I found the broken tabs.
    In short, how much will cost to modify both pillars and install the new tabs? I also will need the “ship to” address and approximate turn around time to fix the pillars.

    Thanks,

    1. Our windshield post repair service is $94.50 per post and currently around a month or so turnaround. Just ship it in to the address below, include your contact information in the box with them, and we will contact you regarding billing once we have the posts in.

      13550 Three Oaks Rd, Sawyer, MI 49125

  3. I have a set of 1959 side posts that are broken, they are re-chromed and no one saw that they were broke. i didn’t see how much the repair would cost? so how much and how fast?

  4. I’ve read about your procedure which sound like a great cost-effective way to solve a tricky problem. Both of mine on our ’56 need this service to restore the tabs. What I don’t understand is this sentence:
    The tab mounting screw will protrude a bit after tab installation. The exposed screw should be ground away (a 4″ cut off wheel disk works well for this task).
    Why not use shorter screws or grind off the ones you have to an appropriate length before installation??
    tnx

  5. My 56 seems to have sagged dash/windshield as the windshield post/door post do not line up, windshield/dash is lower – anyone have any recommendations for the fix?

  6. I just finished looking at all the illustrations for repairing windshield posts. All I can say is, Awesome. Thank You for making it so clear.

  7. Thanks for this nice piece of info. I currently have a right hand that needs repair. What is cost to provide a repaired 1962 post. I will provide to and from shipping/packing?

  8. Doing a complete restoration of my 1959 Corvette. Have owned this car for 50 years. Removed the windshield and found broken post tab on right side. What is the procedure and cost for the tab replacement. I feel it wise to do the replacement on the left side while disassembled. Can you also provide re-chroming if needed? Would prefer to keep my original posts and not an exchange if possible.

    1. We would also need our windshield posts rechromed for our 1961. Were you able to find any place that provides this service?

  9. I have a 1978 that the interior lights are inoperable with the doors being open and closed, the lights work with the headlamp switch all the door switches work properly. I have replaced the head lamp switch and all the bulbs, this car does not have a dimmer relay. Anyone have any thoughts on this??

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