Windshield Installation Guide 1

Windshield Installation Guide




These instructions are a guide only, many applications require variation(s) from this guide. The installer assumes all risk. I welcome any comments or suggestions to improve on this guide.

Alan drclockatpa.net

Do not stretch the rubber molding while fitting them to the glass......by doing so, you'll wind up short as the rubber returns to the original length.

Always start drilling into fiberglass with the drill bit in reverse to allow for penetration through the gelcoat, then you can change the direction of the drill to complete the hole without creating a chip in the surface of the gelcoat.

Do a search here to locate post template measurements that have been previously posted here.

It is important to allow the entire windshield frame to slightly float as a unit rather than over tighten it............. It Will Break

Start by drilling the windshield post holes into the top of the L & R fender area .....It is critical that you drill the holes only slightly larger than the actual diameter of the female threaded post .... you can open them up if need be with a file if necessary.
Be sure to drill the holes at a forward angle that is the same as the female threaded post nipples. Again, do a search here to locate
template measurements that have been previously posted. (Post mock up models will be available for loan in the near future)

Dry fit the upper rubber U channel to the top of the windshield, ....Do Not Stretch It...carefully cutting off any excess evenly at the windshield bottom.

Dry fit the lower rubber molding to the base of the windshield (tap it into place with a rubber mallet) cut the ends of the rubber the same angle as the vertical edge of the windshield post against the U channel....leaving a bit extra here as you can trim it back later.
Do Not Stretch It.

Remove the prefit rubber pieces and cement them back onto the glass as you had positioned them above with a good grade of contact adhesive.

Drill a 1/4" hole centered in the rearward top of the upper aluminum windshield frame for the support rod.

Slide the upper windshield frame over the rubber U channel you have glued to the glass, tapping it with a rubber mallet as you push it on, If there is too much resistance , remove the frame and gently ......tweek - bend the frame over your knee to obtain a better fit. Once you have the best fit to the windshield glass, mark the frame where it meets the base of the glass. ( You will find that to fit correctly and allowing for the windshield to "lay back", you'll have to taper the cut off higher on the back side of the frame, clean cut with a fine file).
Starting where the windshield wiper posts come thru the cowl, cover the area between the post pods and back 4" -5" with blue masking tape
Starting where the windshield wiper posts come thru the cowl, cover the area between the post pods and the radius for a good fit.

Cut 1/4" off the edges of the bottom frame tabs (shorten) on the windshield base molding , this hides the edge of the tabs under the rubber base molding, the tabs will bend a bit as you snip them away but can easily be flattened back to shape with a hammer on a
hard surface.

Drill 3/16"holes centered in every other tab of the windshield base molding.

With the upper frame set onto the windshield, set the windshield on to the body cowl area 1/2 " rearward of the windshield wiper pod (Any less of a distance and you will have a wiper arm to windshield base rubber interference and too far back, you will not be
able to get a socket onto the bolt head under the windshield post.)

Starting at the center, slide the aluminum base frame tabs under the rubber base pushing it snugly against the rubber base. Mark
the tape, every inch where the forward edge of the frame is at. Cut any excess at the windshield post, this cut is also done at the the
same angle as the leading edge of the post.

Remove the windshield assembly from the cowl and set it aside in a safe area.

Carefully place the forward edge of the windshield base molding along the marks you just made, drill thru the 3/16" holes you made
previously and continue to drill through the fiberglass cowl area. As you drill each hole, loosely set a rivet into the hole you just made
to temporarly secure the frame base before you more on to the next hole.

Fit and glue the dash vinyl into place with the forward edge trimmed 1/2" rearward of the line you marked on the tape to reference the
windshield base placement. ( This is done so that the GM windshield GM adhesive adheres to the aluminum and not the dash vinyl.)

Cut a piece of rubber fender welting 8" longer on each side of measured distance from the outer edges of the windshield posts.
The bead on the rubber welting is for cosmetics as well as sealing.

Starting at the passenger side, remove a few of the temporary rivets at a time and sandwich the rubber fender welting "seal" between
the aluminum base molding and the cowl and gently push an awl into the rubber to open the holes into the rubber being careful that
it doesn't move or stretch as you go along. Again replace the tempory rivets without affixing them to the body

Start at the center of the base windshield molding, begin to rivet it to the cowl alternating Left then Right being careful not to move
the molding away from the line you marked on the taped cowl area.

Set the windshield assembly back on and confirm that the base molding fits evenly against the base rubber without any gaps. If you do
have a gap, drill out the rivet(s) nearest to the gap, redrilling close by on the same tab and set a new rivet. ( The old hole will be hidden under the rubber base molding.)
On the top end the support rod there is a slot cut into it to allow the rod to hook in the windshield frame , the cut is too far back from the end causing the rod to pertrude too far into the windshield frame and possibly hitting against the glass, my fix is to grind off the excess until you have no more than a 1/32" thickness forward of the cut slot.

Place the center support rod into the hole in the center of the upper frame allowing it to seat in the slot on the rod pass it down through the dash hole, don't put a nut and washer on it yet.(You may have to tip the assembly back a bit for the rod to set into the hole.)

Run a 30" bead of GM windshield adhesive placing it 1/8" back from the vertical edge of the windshield base frame...the base rubber will be placed on to this and when dry, will secure the windshield to the cowl and keep it from pulling away from the base frame by tipping
back slightly when the top is latched to the upper windshield frame....Do Not get this stuff on your skin, as it begins to dry, it is absolutely impossible to remove and can only wear off naturally with time.

Take a 1/4" washer and elongate the hole to allow the washer to set flush on the underside of the dash thread a nut onto the rod and hand
tighten only.

Cut a piece of 1/2" ID tubing to fit over the post nipple, this can be cut to the same length as the nipple.

Slide the windshield posts along the upper frame and down into the holes in the upper fenders. Use a large fender washer over the post
nipple and against the underside of the fender, fit a standard washer under the head of the bolt that gets screwed into the post nipple.
Take the extra end portion of the rubber fender welting and place the flat edge under the windshield post and the beading up against the post..... As you wrap it around the post, start to force the bead under the rear and inner portion of the post, this will fill in the gap on the back side of the windshield post, tuck any extra up under the back side of the rubber windshield rubber. With a socket extension and swivel, hand tighten only.(One edge of the fender washer may need to be filed off the allow for clearance on the back corner of the dash area)

Have a helper gently push down with slight pressure on the upper windshield frame, mark the position of the two holes onto the windshield frame, remove the frame, drill and tap for the mounting screws ....Be sure that you tap the holes on the same angle as they are drilled
into the posts or the stainless screws will not thread in correctly and strip out the aluminum. Replace the upper frame, 10 x 24 x 3/4"
oval stainless steel screws go in the bottom holes and 10 x 24x 1/4" screws into the upper hole Don't use screws that arew any longer,
over tighten as you will very easily strip out the aluminum.

Remove a post bolt, add a dab of silicone to the threads and reinstall into the post nipple, Gently tighten the post bolts and the center support rod alternating 1/4 of a turn on each one....Just snug them, allowing for the windshield frame assembly to slightly float. Add a dab of silicone to the center support rod nut so that it cannot work loose. Do not use a nyloc nut as you will not be able to "feel" as the nut becomes snug.

Dab a bit of silicone on each the rivets under the dash area and around the windshield post nipples to seal them....let everything set up for 24 hours.

Thanks Alan for taking the time to share your experiences.---

And THIS is why we call him "Merklin the Magician"!

Much to his chagrin (yer too modest).

+1 thanks for this... please help....

 

from what i understand, the windscreen post sits on top of a rubber seal, then the body, then a washer under the body and then a tube and another washer, then finally the windscreen post bolt to hold it all in place.

 

if the above is correct - then I would think the tube needs to be cut at the same angle as the windscreen posts come through the body.. how do I find this angle? its such a tight spot.... or will the accuracy not matter much?

You have the stack-up correct except that Alan does not use the Porsche-style rubber gasket on the bottom of the post, using VW fender welting instead (re-read his post).   And yes, the tube should be cut to the same angle as the underside of the cowl.  I get up in there (yes it's tight) with a small (1/2 Inch wide) straight edge after the tube and bolt are loosely assembled and draw a line across the tube to get a general idea of the angle, then cut the tube and try it.  It usually needs a touch-up or two until you get it right (or as close as you can), then assemble everything per Alan's instructions.  

 

Alan doesn't use the rubber gasket under the corner post.  He runs a piece of rubber VW fender welting under the bottom "L" channel and continues it under and around the corner post to finish it off, then tucks it in under the windshield bottom rubber gasket just inside of the corner post to hide the end.  It looks great when done and very effectively seals the bottom of the windshield from water invasion.  I usually trim a bit off of the tab to make it easier to run under corner post.

 

One last thing:  When you do the final assembly, I apply anti-seize to the bolt threads as they tend to rust over time and then you can't get them out - ever.  Alan uses silicone instead, which is a good idea as it both seals the threads to prevent rusting and holds everything from vibrating loose.

cool thanks Gordon

I'll source some tube and get to work!

 

This past weekend, I successfully replaced my third windshield without removing the posts.  Easy peasy.

You know, these windshields really aren't as fragile or intolerant as many people believe.  I've replaced six of them now - four of them in Beaufort, alone - and haven't had any problems, other than getting the teeny-tiny-channel in the bottom of the bottom rubber gasket to fit over that silly vertical lip on the lower trim molding.  I believe that Alan doesn't even try to do that any more (as shown by his instructions to just butt the rubber up against it).  The really key things are:

 

1.  Cement the rubber gaskets to the glass (after you get them cut to the proper length and have mitered/trimmed the ends) with contact cement

 

2.  Adhere the lower rubber gasket to the cowl trim piece with that 3M windshield adhesive

 

3.  Use the "Alan recommended" screw lengths for the corner post to top frame

 

4.  Tighten everything (corner posts and center strut) no more than 1 turn beyond finger tight, especially the center strut.  Tightening that center strut even a little too tight will certainly cause the glass to crack - maybe not right off, but overnight or when the first person uses the windshield as a hand-hold to get into the car.

 

This is a terrific write-up on a popular topic.  If you haven't already stored it as a file or printed it for your private "user's manual", you certainly should.

 

gn

Hi I would be interested in  talking to anyone  I have a thunder ranch. I have to remove the winshield to install snaps for the cover. Can the windshield be removed without removing the posts from the body, just undoing the side screws and the center rod  I have read everything but am still not clear.............I will be putting back the same windshield...Thanks in advance   Scott

I've removed the windshield on my Beck a couple of times without removing the posts, but there is no mystery in removing them as well as the bottom strip makes sure everything stays oriented properly.  It's really pretty easy, as long as you're careful.

As Lane says, just remove the two small screws in each corner post and the whole windshield should lift up and out (make sure you're pulling at the same angle as the corner posts).  The only downside is that McBurnie may have used windshield cement to glue it all together.  Windshield cement is black, nasty stuff if you get it onya, but it holds like crazy.  Try emailing him and ask if he glues the windshield in or should it lift right out?  He should know.

 

If, on the other hand, all you want to do is add a couple of snaps, I did mine in my CMC by carefully measuring where I wanted them, then carefully measuring again on the underside of the dash and then drilled holes UP from underneath.  I then used a 90 degree phillips screwdriver to screw in the male snap heads.  A little tedious, but it works and I never had to remove the windshield.

Thank you for all the advice....the owner built the car and says no cement  Thanks once again