Windshield Install Gap - Stumped

[Dave O]

When I try to set the windshield angle at the prescribed setting ( 27 Inches from end of door to top screw on windshield, and bolt holes in frame centered on bar extending into body) I get a large gap between body and WS seal.....approx. 1/2". If I set the windshield at a steeper angle to close the gap, the holes do not line up with the bar. I'm OK with the steeper angle because I am not planning on a soft top. But I would have to drill new holes in the frame. Perhaps this is the way to go.....just don't understand the large difference from the factory set up. I have double checked the body and it seems to be in the correct position. If I raise the center of the body to meet the WS seal, it creates a large gap between the body and top of the dash.

What am I doing wrong??

[IMG][/IMG]

[edwardb]

Whoa, not nice. I'm not familiar with that measurement. But I'm thinking the problem is the angle of the windshield, e.g. you have it tipped back too far. You don't say whether Mk3 or Mk4, and I don't know the difference between the two anyway. But for my Mk3, windshield angle is approximately 51 degrees, relative to top of doors. Definitive measurement for a Mk3 is 33 inches from inside center of windshield to back of cockpit opening. How does your setup compare to either of those?

Other possibilities are that the body isn't sitting down all the way, or that the windshield is somehow bent wrong. Have never heard of that though.

This is a picture of my Mk3, from a very similar angle. It looks like my windshield is standing up a little straighter.

[lmmargheritis]

I took this right out of the mk4build BUILD MANUAL . I do not have first hand experience with the windshield install but I do know that this is a great resouce.

While the windshield can be mounted at several different angles, a popular choice is 53 degrees, since this fits the specification for a soft top option (this build does not include a soft top).

The 53° angle can be achieved by first making a 2×4 wood brace that measures exactly 33 7/8” (with notches cut out to fit the whindshield and the body) and using it to hold the windshield in place, shown as position A in the photo.

Then measure the distance B between the top of the windshield and the cockpit floor (before insulation and carpet), which should be exactly 36 1/4”.

Adjust the windshield angle, as necessary, to get as close as possible to the correct A and B distances.

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glassprofile[1].jpg

[QSL]

dave, is the rubber seal on the bottom of the windshield? Mine sits a bit above the body, but the seal hides the gap.

[Dave M]

When I put the top on my car I cut a piece of card board with the 53* angle and used that to adjust my windsheild to the proper angle. Just by dumb luck, when I built the car originally I set it close to that so it didn't have to be moved far. I would suggest you set it at that just in case you or someone else wants to put a top on it in the future.
On another note , I don't beleive the holes in the side frames are required to be centered down the middle. I know the ones on my MKIII aren't. That may be part of your problem. So yes you'll probably have to redrill them. You really need to get the windshield situated perfectly before you mark and drill. The holes in the body sometimes need to tweeked a bit too, to allow for proper positioning.

[Dave O]

Thanks for the replies folks. I am working on a Mk4.
Edwardb - I agree mine is leaning back more than yours. Relative to the top of the doors, it measures 49 degrees. When I move it to 51 degrees it definitely help, although there is more gap below the windshield than I am comfortable with. The seal barely touches the body in the middle. Also, the holes in the frame do not match angle of the side bars of the windshield. I can drill a hole in the top location, but the bar is not even showing in the lower hole....it is behind the hole. Here again, I could drill a different location for the lower hole.

Immargheritis - When I set the windshield up according to the mk4 build manual, the result is basically what you see in my photograph. Also the distance from the cockpit floor to top of windshield is 37 1/2". This might
mean a windshield with excessive bow in it.

QSL - Yes the seal is on the bottom of the windshield.


Only other cause I can think of is the body not sitting in right position. How can I verify this? It is sitting evenly on the frame as far as I can see. Originally there was a small gap between the dash and the rolled cockpit edge. I was having problems getting the PS windshield side bar to go into the slot in the body. Pushing the body forward solved that issue. Looking at the bulb seal on the firewall (firewall forward kit) reveals that the seal is "crushed" more in the middle than on the ends. Is this normal?

[edwardb]

Something doesn't sound right if the bulb seal is pushed down in the center of your firewall more than the sides. But really hard to say.

The one thing I would offer based on what you describe is to not be married to the body cut-outs for the windshield bars. It's a little bit of a red flag to me that the bars don't match up better with the mounts on the chassis.

Put the body where it belongs, and if the cut-outs don't line up allowing the bars to mount properly, adjust the cut-outs by lengthening, widening, whatever. Probably what you need to trim would be covered by the bezels. If not, can still be easily filled during paint. There was a thread a while ago about a guy who didn't have room for his wipers, and turned out he just needed to adjust the cut-outs to the allow the windshield to move back a little. Some would argue the factory cut-outs in the body are only suggestions of the proper location(s).

Just for grins, with the bars off, is there a place on the body the windshield sits properly where the angle is about right? (Don't try that without help!)

[Dave O]

Thanks Edwardb. I will give that a try when my helper (Son) gets back. I think you are right about being too married to the factory cut out locations.

[blate]

I had exactly the same issue on mine. Basically, I widened the passenger side hole (doing this still allowed the windshield to be centered). The windshield post are basically pinching into each other. The holes are not far enough apart (at least mine they weren't).

[rick8928]

Concur with need to lengthen/widen the body cutouts for the windshield posts. I messed with mine in order to get a good fit, and so did my buddy PJ (both Mk 4s).

[Peter Paton]

On my MK3.1, there are 2 spacers that mount between the dash hoop and the body where the rear view mirror mounts. That tended to raise the center of the body about 1/2". Don't know if that will take up the space under the windshield, but it will certainly help.

Peter

[Dave O]

I was not aware of these spacers Peter. Will look to see if the Mk4 is supposed to have them. That would definitely help. Thanks

[Dave O]

I do not see any reference to spacers for mounting the rear view mirror in the Mk4 manual. So I will start with widening the windshield post slots in the body and see where that leads me. Does any MK4 owners know of such spacers mentioned by Peter above? If so, photos would be appreciated.
David

[edwardb]

Originally Posted by Dave O

I do not see any reference to spacers for mounting the rear view mirror in the Mk4 manual. So I will start with widening the windshield post slots in the body and see where that leads me. Does any MK4 owners know of such spacers mentioned by Peter above? If so, photos would be appreciated. David

Just looked through the Mk4 manual (love the electronic version) and there is no reference to the spacers under the rear view mirror, like on my Mk3 and I assume previous versions. So FF must have deleted it.

FWIW, even on Mk3's, not everyone used them. My Mk3, pictured in post #2, doesn't have the spacer installed. I mounted the rear view mirror at the top of the windshield, and I never saw any reason to add the spacer.

[Thumper135]

I agree with the body holes not being where they should be. I have a MK3 and the passenger side was off by about a quarter of an inch to the rear. I had to do a little body filler to mine to make sure the hole was covered by the trim ring. My kit didn’t come with any spacers for the mirror either. I had to make one about 1/16” thick to make up the space between the hoop and the body, but that didn’t have any effect on the windshields mounting and I did the spacer thing after the glass was in place.

[Dave O]

Just a quick follow up to thank everyone for their help. I widened and lengthened the body slots and the windshield now fits properly.
The Forum comes through for me again!!
[IMG][/IMG]

[Mr. Barry]

Good job! My only question is why you waited till the car was painted to fit everything?....
For others in the build stage, I strongly recommend fitting everything on the car BEFORE you paint it....
This has been stressed a million times over the years.....
Good luck with your car, and enjoy the ride.
Edward

[lmmargheritis]

The roadster is not yet painted. The Mk4 comes in red gel coat. Notice the mold parting lines. Probably would look fine from 30 feet out though.

Originally Posted by Mr. Barry

Good job! My only question is why you waited till the car was painted to fit everything?....
For others in the build stage, I strongly recommend fitting everything on the car BEFORE you paint it....
This has been stressed a million times over the years.....
Good luck with your car, and enjoy the ride.
Edward

[Mr. Barry]

DOH!....I saw the stripes on edwardb's post, and my brain "conflated" the two cars....
Sorry for my misplaced admonition.
Edward

[PhoneGuy]

Originally Posted by Dave O

Just a quick follow up to thank everyone for their help. I widened and lengthened the body slots and the windshield now fits properly.
The Forum comes through for me again!!

Thanks for posting the final end result as I am installing my windshield this weekend. Guess the dremel will come in handy..

[bbk347]

The "spacers" for the rear view mirror used to be packaged with the rear view mirror. Two small nylon tubes that the hold down screws for the mirror would pass through as they were connected through the body to the top hoop. The MK 4 has a different body shape right there though and it wouldn't surprise me if the spacers were no longer needed. With your windshield temporarily where you want it, reach under the dash and feel for the space (if any) between the top of the hoop and the underside of the body. You need to fill that space (if any) because as the mirror gets tightened down, it'll pull the body away from the bottom of the windshield. Also in the final assembly, don't forget (it's real easy to) to install the rear view mirror first!

[timp2]

I bought a convertible top and had gap problems also when I changed the windshield angle. Most of the problem was cured when I enlarged the windshield post holes but I could still see minute cracks of light between the windshield gasket and the cowl. I bought the thinnest double sided 3M automotive tape that I could find and adhered it just slightly inboard of the leading edge of the gasket, I left the plastic strip on the cowl side while I re-installed the windshield. When the angle was set I slowly pulled the protective strip from the cowl side of the tape while putting slight pressure on the area the strip was being removed from by sliding my thumb along the windshield gasket. No light nor water penetrates that gap now although there certainly are water intrusion challenges from other areas. Tip, if you try this leave a tab of protective strip about a half inch long on the cowl side of the tape, makes it a lot easier to expose the adhesive when the windshield is in place.

[CraigS]

Mine is a MkII but I think these ideas are generic. The guy who built my car originally did it kind of quickly and I have done a lot of rework. Two windshield related things came up. As you already discovered the holes in the body need opening. I discovered they definately need to be clearanced to the support posts. If the fiberglass contacts the posts you will end up w/ squeakes over bumps or when you lean against the fender working in the engine compartment. For the same reason I recommend that the windshield be mounted slightly above the body. The rubber seal should contact the body but the lower glass frame should not. I put a few 1/4 inch plywood spacers under the frame and then tightened the mount bolts. After I removed the spacers and drove the car some it settled to where there is about 1/8 inch clearance body to windshield frame. These two adjustments made a vast improvement in the solid feel of the car over small sharp bumps.