How to Change a Car Windshield | DIY Instructions
In this article, you will find instructions on how to change a cracked car windshield.
What you will need
- Windshield Removal Tool
- (2x) 3M Auto Glass Windshield Urethane (08693) Adhesive
- Protective Gloves
- Two People
- Razor Blade
- Urethane Primer
- Windshield Suction Cups
- Caulk Gun (Electric preferred)
- Front and rear windshields play a key role in the structural integrity and safety of your vehicle. For this reason, we recommend to have a certified installer replace your windshield.
Start by removing the wiper arms, trims inside, and rearview mirror.
Remove exterior trim around the windshield. The exterior windshield trim has clips that it snaps in. Carefully pry out the trim around the windshield. Carefully remove any clips, fasteners, and retainers. Avoid breaking or losing them because they usually can be re-used.
- Remove the windshield cowl.
- Cut the urethane seal around the perimeter of the windshield. You will need a special long knife for this step. The easiest and cheapest way to remove the windshield is to use an 18" Urethane Cut-Out Knife, which is typically used by professionals. Cut the urethane around all the perimeter of the windscreen. As you cut out the windshield, be careful to minimize damage to the pinch weld. Other methods to cut out the urethane include using a guitar string or a stiff, thin wire.
Once the urethane is cut, remove the cracked windshield. Next, use a glass scraper blade to remove the old urethane. Watch the following video on how to quickly and easily remove the old urethane.
- Clean any dirt or debris left on the frame. There should be no dirt or debris where the urethane is applied.
Prime the pinch weld. As you cut out the urethane, you probably created a few scratches. Apply urethane primer to the perimeter of the windshield, inside the edge, and also in the window channel. The primer can help the urethane glue better and act as a rust prohibiter when applied to the window channel, especially if there are any scratches. Don't worry if you created a few small scratches; even an auto glass professional can't avoid making a few scratches to the pinch weld. Just make sure to always use urethane primer to ensure that rust doesn't develop. If there is rust in this area, you may want to sand it down, then prime it. After you apply the primer, wait a few minutes before you apply the urethane bead.
- Apply a bead of urethane around all the perimeter of the window frame. The bead needs to be continuous, with no gaps in between. Start by removing the bottom cap from the urethane cartridge, then install it on your caulk gun. Carefully lay the bead of urethane. Try to keep the bead of urethane as one continues line. Avoid stops and move your hand at a constant speed.
- If there are any spots that the urethane bead is not continuous, add some more urethane or use a small spatula to fix the urethane.
- Be careful not to let any urethane fall on your car's paint. Removing the urethane from the paint can be challenging.
- Install the new windshield. We would recommend that you get help from another person to help you lay down the new windshield.
- Once you have placed the windshield on the car, push it with the palm of your hand all around the windshield glue line.
- Re-install the cowling wipers, trims, and mirrors that you may have removed.
- Allow the car to remain parked for a few hours and for the urethane to cure. It can take up to 48 hours for the urethane to completely cure. See note on the back of the urethane cartridge.
- If you are planning on installing a windshield by yourself, it is recommended that you use heavy-duty suction cups to handle the windshield. Make sure to use rubber gloves so that you don't contaminate the windshield glass or get any grease on the windshield.
- If you miss any spots or the bead is too thin, just come back later. Some windscreens may have small plastic clips around the frame. The clips are there to help align the windshield. If you need to replace the clips, just slide them and lock them into place.
- Once you apply the urethane to the car, don't wait too long to install the windshield. The sooner you install the windshield, the better.
- Don't use a car wash right after you have installed a new windshield.
- If you have a newer car, you may want to leave this job up to the professionals. Call auto glass repair shops in your area and get a few windshield replacement quotes.
Do NOT use silicone to install a windshield. ONLY USE auto glass urethane. To create a strong bond between the windshield and the car frame, you will need approximately 15-20 fl. oz. of automotive grade urethane.
Note that the windshield is part of the structural integrity of the car, especially on today's unibody vehicles.
If you are installing the windshield for the first time, you will most likely try to apply the urethane using a hand caulking gun. While the urethane can be applied with a hand caulking gun, it is very difficult to apply a continuous bead.
We recommend that you heat up the urethane cartridge before you apply it, or it will be nearly impossible to get the urethane to come out. Note that professionals will either use an air-powered caulk gun.
Always use protective eyewear and gloves when you handle glass.
Windshield supports your roof and helps the dashboards and A-pillar airbags function properly. A weak bond between the glass and the body can cause the windshield to come off during an accident or when the airbag goes off.
Published on: Saturday, December 31, 2016.
Hi, Thanks for putting together this free windshield replacemend guide. I had replace the back glass on my Mercedes and was quoted $1000+ to change it. Found a used rear glass at a junk yard and installed it using the tips found here. I have to say that you were right about getting the urethane out of the cartridge, it was the most difficult part. Ended up getting a powered caulk gun and it was much easier.