By Denis Moore
When installing a Roadster windshield, the key words are "No stress should be on the glass at all." If the frame doesn't fit the glass, the frame can be bent, not the glass.
— Bruce Baker
[Editor: Installing a Convertible D or Roadster windshield is very, very, tricky. You can also download this article
as an MS Word file to print out and use in the garage. Be sure and read Roy Smalley's Roadster windshield installation
instructions as well.]
The process described here is for a simple replacement of a broken windshield in an already painted car without other windshield related difficulties, i.e. aluminum strips, seals etc.
It would be the same procedure for fitting the windshield to a restored car after metalwork/bodywork has been completed but prior to painting.
- Remove the wiper arms and the nuts securing the two aluminum hold down tabs for the three trim strips.
- Remove the three aluminum cowl strips from the lower seal by pulling up and out from the center toward the windshield posts.
- Remove the two socket head bolts holding the windshield post to the body.
- Remove the windshield tension rod nut from the tension rod under the dash and the two screws holding the rod to the windshield frame. Note: Early Convertible Ds did not have these screws. The rod simply pulls out.
- Removal of both seats will make this whole job easier.
- With 2” masking tape, tape the glass to the windshield frame by running the tape over the top of the frame and securing the tape to the glass in at least four places.
- Standing in the cockpit facing the front of the car, hold the windshield posts, one in each hand. Pull up and back gently until the posts slip from their holes in the body.
- Remove the entire assembly including the lower seal and place it on a soft surface.
- Remove the tape securing the glass to the frame.
- Remove the lower seal.
- Gently push the glass down towards the open end of the frame alternating left and right until the glass is separated from the frame (leave the posts attached the upper frame)
- Remove the upper seal from either the frame or the glass depending on where it stays..
- Examine the inside of the windshield frame and post assembly.
- Insure that the screws that hold the posts to the frame, the tension rod to the frame, the sun visor to the frame do not protrude too far into the frame.
- Clean any rubber or glue from inside the frame and post assembly.
- If any of these screws protrude beyond the inside surface of the frame, grind them smooth to the frame.
- Examine the two lower windshield frames screwed/riveted to the body. Ensure they are complete, secure in position and the screws/rivets are flush as possible to the body. If this is a restoration and these frames are being fitted for the first time, secure them with metal screws so they may be moved if this becomes necessary for proper fit.
- Examine the holes in the body that accept the windshield posts, ensuring they are smooth clean and free of dirt.
- With the windshield frame (posts attached), but without the glass, fit the frame to the car by inserting the windshield posts into the holes in the body. Make sure there is no undo binding and the posts can be dropped in the holes without force.
You should use a new upper windshield seal. The new seal will have ribs running along both sides of the seal. These ribs should be trimmed off per the attached factory service bulletin.
- Take the old upper windshield seal and cut it into 1½ inch pieces.
- Take the old lower seal and cut it into 1½ inch pieces.
- Place the pieces of the old upper seal on the new windshield glass, two on each side, one on each corner and two on top, in the middle.
- Lubricate the pieces with Armor-All, dish soap or other lubricant.
- Gently lift the fame and posts to the glass with the upper seal pieces in place. Gently press the glass into place until the glass is fully seated in the upper frame and both posts. CAUTION: Pay close attention to the curvature of the frame and the glass as you push the glass into the frame to ensure they are approximately the same and are matching as you mate the glass to the frame.
- Install masking tape as done previously to secure the glass to the frame.
- Once in place, examine the glass between the rubber pieces to insure that it is reasonably centered on the frame and not resting up against the metal frame.
- Holding the windshield/frame as you did when you removed it from the car, carry it back to the car and while standing in the cockpit, position the studs of the windshield posts just over the holes in the body on each side so they are lined up for entry.
- Insert the studs of the windshield posts ½ inch into each hole, ensuring that they are no binding and go in easily.
- If all seems well continue dropping the posts into the holes in the body until the bottoms of the posts are flush with the windshield post seal. Check the bottoms of the post/seal to insure they meet flush all way around.
- Examine the lower edge of the glass and its relationship to the L shaped frame attached to the body.
- Examine the angle of the glass and the angle of the L shaped piece. Ensure it is reasonably uniform from one side to the other. See the attached factory diagram.
- Using the 1 ½ inch pieces of the lower seal, put two in the center of the windshield. You may have to lift the windshield slightly in order to do this.
- From the center, move the pieces one at a time from the center of the glass to the windshield post. You are checking the uniformity of the gap between the L shaped piece and the glass. The rubber piece should move without binding. If the gap is too tight as you move toward the post, the seal piece will drag and/or the glass will move up as the seal pushes on the glass.
- If the seal piece gets too tight as you move toward the posts without the windshield being secured to the body with bolts, it is highly likely that the gap is too small and will need to be increased by grinding the glass (glass shop) in order to prevent the glass from binding when bolted to the car.
- If all is OK, insert the bolts in the bottom of the windshield posts and secure the frame to the body finger tight and half a turn of the wrench. Add the tension rod to the frame and secure in the same manner, finger tight half a turn.
- Re-examine everything, moving the rubber pieces if you have to insure the glass is not binding on the frame or the posts.
- If the gap between the lower frame and the glass appears too great in the center, and the glass does not meet the seal the way it does on the sides, the tension rod in the final assembly may be able to make up the distance and/or you may be able to move the glass down towards the lower seal once the tape is removed and the glass is allowed to float. In any case, do not worry about it now. This is a game of fractions of an inch here and fractions of an inch there.
- If all is OK, remove the entire windshield frame and glass from the car. Remove the tape, small pieces and remove the glass from the frame.
- Install the upper seal to the glass as shown in Exhibit A in the factory drawings [shown at right, click for larger version]
- With a knife or razor blade, make three slits in the covered portion of the upper seal in each corner to facilitate fitting the seal to the upper frame. Install the frame with seal on to the new glass and the new upper seal, pressing gently to ensure that the seal is full seated in the bottom of the frame and presents a uniform appearance on the inside and outside of the glass.
- Install the new lower seal to the glass. Mark the upper seal where it meets the lower seal at the posts. Remove the lower seal. Trim the upper seal where you made the marks at both posts.
- Reapply the masking tape to hold the glass to the upper frame as done previously.
- Install the new lower seal to the L shaped frame attached to the body. Trim the ends of the lower seal the approximate length from post to post. Leave more length than you think you need. You can always trim later.
- With the lower seal in place on the L shaped frame, install the windshield assembly from the cockpit of the car lowering the posts slowly in the holes in the body ensuring there is no binding. Do NOT bolt the frame to the body yet.
- Working from the center to the sides, ensure the lower seal is properly positioned on the L shaped frame attached to the body, the glass and the interior lip that goes over the dashboard. Keep in mind that the aluminum trim strips attached to the outside of the lower seal will help position the lower seal properly pressing the seal down to the cowl on the outside.
- Trim the ends of the seals where they meet at the posts in order to get a good seal and make a nice appearance. A little black silicone will be helpful here when you are all done.
- Install the bolts that hold the posts to the body and the windshield tension rod, all three finger tight and half a turn. Remove the masking tape and allow the glass to move down towards the lower seal. It need not be pushed tight up against the upper frame. You should be able to move the glass at this point slightly up and down within the frame.
- Re-examine all the contact points around the complete frame to ensure the upper seal is proper and correct, the lower seal is proper and correct and the posts and post seal to the body are properly positioned and flush to the body.
- If all is OK, tighten the windshield posts another 4 to 5 turns with a wrench. Tighten the tension rod only enough to close any gap that might exist between the glass and the lower seal in the middle. Do not over tighten anything. Leave it alone. Walk away. Come back in a day or two.
- When you come back, test the posts and tension rod for tightness and tighten if necessary. Test fit the top frame.
- Now install the five pieces of aluminum trim to the outside of the outer seal. Start in the corners and work to the center, Then the centerpiece and the lastly the two wiper tabs. This is not a fun job and is easier with two people as you must fit the trim piece into the slot in the lower seal. Opening the slit a little with an awl or screwdriver will help, a drawstring will help a lot and of course lubricant but sparingly.