Chevy Avalanche Fan Club of North America Magazine

 
Home > Fun Stuff > CAFCNA Magazine - March 2002 > Page 4

What Is That Flapping Noise???

A picture of a bug shield off of Naylor99's AvalancheSo you bought a new Chevrolet Avalanche.  Maybe you had the dealer install a bug shield before your brought it home.  Maybe you bought an aftermarket kit and installed it on your own.  It looks great and your hood will be perfect for years to come but something is wrong.  Whenever you drive at highway speeds if things are just right you're hearing the strangest flapping noise.  It seems to be coming from the cowl or the windshield but that makes no sense at all - the bug shield is almost four feet away.  What's wrong with my Avalanche!

Actually there isn't anything wrong except for the install job of your bug shield wasn't finished.  When you install a bug shield on your Avalanche it changes the aerodynamics of the front end.  Two vortexes are formed off the edges and they travel rearward and smack right on the edges of your windshield.  What you're hearing is the windshield trim on both the driver and passenger side vibrating.  That's the bad news.  The good news is for under $10 and thirty minutes of your time you can make the noise go away - forever.

If you ordered a genuine General Motors bug shield for your Avalanche it should have come with some double sided tape.  You know, that tape you didn't install (or maybe your dealer didn't install).  If you purchased an aftermarket kit (Lund is a popular choice) it probably didn't come with any tape.

If you don't have double sided tape a trip to Radio Shack store will solve all your problems.  You need to get two rolls of 40" long double-sided adhesive tape and a bottle of professional grade tape head cleaner.  The tape head cleaner contains isopropyl alcohol that you need to prep the surface area to make sure you only do this job once.  You'll also need a sharp knife, a new disposal box cutter is best, a grease pencil, and a t-15 torx driver.  The driver should have a short handle.

Location of the windshield trim on the Chevrolet AvalancheStep1:  With your grease pencil run it down the side of the windshield following along the edge of the trim that runs from the door to the hood on the driver and passenger side.  This will help you gauge where to put the double sided tape.

Step 2:  Open up both the driver and passenger doors.  Grab the weather stripping at the top of the door right where it starts to curve down toward the hood.  Firmly but gently lift up and slightly toward you until the stripping pulls away out of the track.  Continue to remove the stripping all the way down to the hood.  This will reveal the windshield trim piece.  Repeat on the other side of your vehicle.  There is no need to remove the weather stripping past the A pillar and you can just leave it hanging down.

Step 3:  Take your t-15 torx driver and remove the four screws along the driver side windshield trim.  The bottom one will be the hardest due to limited room between the door and the trim.  You will not be able to remove the fifth screw that is located just above the upper door hinge.  Repeat the procedure on the passenger side.

Step 4:  Grab the windshield trim between where the top screw and the second screw was located.  The trim is still held in place by a two-inch piece of double sided tape.  Pull the trim firmly but careful towards your body until the tape releases.  Gently rotate the trim piece down until it is parallel with the ground.  Repeat on the passenger side.

Step 5:  Take a cotton towel and wet the corner with isopropyl alcohol.  Be careful not to drip any on your interior or the paint.  Rub down the inside of the windshield trim, the sheet metal that was under the trim on the A pillar, and the exposed windshield glass to your grease pencil line.  Repeat this on both sides until the trim is clean.  Take a dry corner of the towel and make sure the surface is dry.

Step 6:  With your fingernail, or knife if you're careful, remove as much of the old adhesive tape from the trim and the sheet metal of the A pillar.  Repeat on the other side.  Some alcohol will help dissolve the old adhesive.

Step 7:  Take the double sided tape and run it down along the length of the A pillar covering up the four screw holes.  Cut the end off at the base of the windshield.  Do not remove the cover from the other side of the tape yet!  Repeat on the other side.

Step 8:  With the remaining tape, starting at the hood, place the tape along the edge of your grease pencil line and move up towards the top of the windshield.  The tape should flex to the curve of the glass.  When you run out of tape take your box cutter and split it along the outer edge of the windshield making a second strip.  Take the strip and continue along the edge until you reach the top of the windshield and dispose of the remainder.  Do not remove the cover from the other side of the tape yet!

Step 9:  Remove the protective cover from the tape along the A pillar and the windshield.  Gently rotate the windshield trim back into place and press firmly.  You may want to consider punching through the tape to expose the top most screw hole so you line the piece up correctly.  Take your torx set and return the four screws.  Do the bottom one first, then the top, and then the middle.  Do not torque down the screws until all four are in place.  Once all four are in place torque them down firmly and repeat the procedure on the passenger side.

Step 10:  You're almost done!  With the tape now applied on both sides and the trim back in place, replace the weather stripping by reversing the removal procedure.  It helps if you grab the base of the stripping with one hand and pull down while pushing down with the other.  The weather stripping will almost feel like it is clicking into place.  Repeat on the passenger side.

Step 11:  Using a non-ammonia based cleaner clean the windshield of your grease pencil markings.  If any double sided tape is exposed from under the trim take your box cutter and carefully trim the edges.  If you're not careful you can nick your windshield trim.

Go out and drive on the highway.  Tada!  The flapping noise you heard is now gone and your windshield trim is securely in place.

Author Credit:  David Obelcz
Photo Credit:  Naylor99 and General Motors Corporation