In The Clear

Always follow the OEM installation procedure and use Mopar® replacement glass when replacing damaged windshields and backlights to maintain the vehicle’s structural integrity.

One of the most common tasks in the body shop is replacing body glass. This glass includes the windshield, door, quarter panel glass and rear, or liftgate, glass. How many damaged windshields have you replaced? Windshield replacement is so common that there are companies that only provide this service. And, of course, collision damage to a vehicle will often break the door, quarter and rear glass. In this article, we will cover the basics of replacing stationary glass. Because of the complexity of power window controls, movable door glass will be saved for another day.

WINDSHIELD GLASS

The windshield is attached to the window frame, or fence, with a urethane adhesive. This adhesive is applied cold and seals the surface area between the fence and the glass. A primer is used to adhere the urethane to the windshield. Those are the basics. Let’s review the removal and the installation.

Removing the windshield is pretty straightforward. First, remove the windshield wiper arms, the rear view mirror, then the cowl grille. Next remove any molding from around the windshield. With the help of an assistant and a wire-type windshield cutting tool, cut and separate the urethane adhesive around the entire perimeter of the windshield. A power cutting device can be used, if available. Lift the windshield out of the vehicle, being especially careful if the glass is severely damaged.

Before installing the new windshield, roll down the right and left door windows. This will prevent pressurizing the passenger compartment. Failure to take this precautionary step can cause water leaks if a door is slammed before the urethane bonding is cured.

To avoid stressing the replacement windshield, level the original bead of urethane on the fence to a thickness of about 1 mm (about 0.05"). This can be done using a basic razor knife. Also, remove any damaged spacers. Install new adhesive spacers along the fence, as required.

Place the replacement windshield into the windshield opening. Position the glass in the center of the opening against the compression spacers, as shown in Figure 1. Verify that the windshield lays evenly against the fence at the top, bottom and sides of the opening. If it does not, the fence must be formed to the shape of the windshield. Mark the glass with a grease pencil or masking tape for reference when installing it. Remove the windshield and place it on a suitable surface supported by two padded, wooden blocks. Clean the inside of the windshield with an ammonia-based cleaner and a lint-free cloth. Do not use solvent-based cleaners to clean the glass. This can lead to poor glass adhesion.

Apply glass prep adhesion promoter around the perimeter of the windshield, about 1-inch wide and about a quarter inch from the edge. Wipe dry with a clean, lint-free cloth until no streaks are visible. Then, apply glass primer around the perimeter of the glass. Allow three minutes for it to dry. Use a flashlight to verify that the primer is completely and evenly installed. Re-prime any area that is not fully and evenly primed.

Clean the windshield fence with an ammonia-based glass cleaner and a lint-free cloth. Then, apply pinch weld primer around the fence (about ¾" wide). Allow three minutes for it to dry.

Apply a 10 mm (7/16") wide bead of adhesive, 6 mm (1/4") from the edge, to the glass starting at the bottom center of the windshield. Run the end of the bead on the windshield parallel to the the start of the bead and smooth the ends flush.

With an assistant, position the windshield over the opening. Using the grease pencil marks or tape as a guide, align the windshield to the opening. Carefully lower the glass and guide it into its proper position. Push the windshield inward until it comes into contact with the compression spacers on each side and along the bottom.

Remember, the windshield should never be pressed into place by more than one person. It can break if it is pressed on both sides at the same time.

To complete the job, install the molding, cowl grill and rear view mirror.

QUARTER GLASS

Quarter glass, for the purpose of this article, is back side glass found on the minivans. This is the third piece of the glass. On other vehicles, the glass behind the front doors usually can be rolled down. That is a discussion for another issue. Quarter glass replacement is relatively simple.

Remove the C-pillar trim. Unclip the quarter window from the latch at the rear of the window (if this is a power window, unclip the window from the power window pivot). Refer to Figure 2. Remove the hinge retaining nuts and washer at the C-pillar, then separate the quarter window from the vehicle.

Install the quarter glass by positioning the glass in the vehicle window opening. Install the hinge retaining nuts and washers at the C-pillar. Connect the window to the latch at the rear of the window. Finally, install the C-pillar trim.

REAR GLASS

Rear glass is referred to as liftgate glass on minivans and the PT Cruiser, and backlite glass on passenger cars with stationary rear glass. Regardless, there are many similarities in removing and installing this type of glass.

If there is rear windshield wiper arm, remove it. Then, remove the interior trim covers. On all vehicles, disconnect the wire connectors from the rear window defogger and radio antenna, if equipped (Figure 3). Cut the urethane around the perimeter of the rear window glass, then remove the glass.

Installing the rear glass is similar to installing a windshield. As is the case with the windshield, roll down the right and left door windows. This will prevent pressurizing the passenger compartment. Failure to take this precautionary step can cause water leaks if a door is slammed before the urethane bonding is cured.

Clean the inside of the rear glass with an ammonia-based cleaner and a lint-free cloth. Do not use solvent-based cleaners to clean the glass. This can lead to poor glass adhesion.

Apply glass prep adhesion promoter around the perimeter of the windshield, about 1-inch wide and about a quarter inch from the edge. Wipe dry with a clean, lint-free cloth until no streaks are visible. Then, apply glass primer around the perimeter of the glass. Allow three minutes for it to dry.

As is the case with the windshield, the glass opening, or fence, must be formed to the shape of the new glass. This can be done by using a basic razor knife to cut the existing urethane. Apply a 10 mm wide bead (7/16") of urethane along the center line of the window fence.

On passenger cars, such as 1993–2004 LH platform vehicles (300M, Concorde, LHS, New Yorker, Intrepid and Vision), with the aid of an assistant, position the rear window over the opening. Slowly lower the rear window glass to the fence opening and engage over the two flanges located on the fence. Guide the encapsulation into proper position as necessary. Push the rear window inward until it is flush to the roof line and C-pillars.

On a minivan, apply two glass spacer clips to the liftgate about six inches inboard from the edge. With the help of an assistant, slowly lower the glass into the liftgate opening. Push the glass inward until it is flush with the liftgate surface.

In any case, clean the excess urethane from the outside of the glass with Mopar® Super Kleen, P/N 04886330AA, or equivalent. Reconnect the rear defogger connectors (and radio, too). Install any trim panels. Finally, after the urethane has cured, water test the glass edges to verify proper installation.