2005 GMC Yukon Xl 1500

WHILE DRIVING THE SPEEDOMETER WILL STOP DESCENDING AT A SPEED AND WHEN THE DRIVER ACCELERATES, THE NEEDLE WILL RESPOND AS THOUGH THE STICKING POINT WERE THE SPEED OF DECELERATION AND CONTINUE RISING FROM THERE UNTIL THE NEEDLE IS OVER PAST THE LAST LISTED SPEED ON THE FACE OF THE IPC. IT OCCURS ABOUT ONCE EVERY TWO WEEKS AND WHEN IT OCCURS IT IS IMPOSSIBLE TO KNOW WHAT THE SPEED OF THE VEHICLE IS. SO FAR, IT IS POSSIBLE TO CORRECT THE PROBLEM BY LETTING THE VEHICLE SIT, SOMETIMES OVERNIGHT IS NECESSARY, AND START THE VEHICLE AND THEN SHUT IT OFF. THIS DROPS THE SPEEDOMETER NEEDLE ABOUT 5MPH. THE DRIVER MUST CONTINUE TO DO THIS UNTIL THE NEEDLE HAS GONE FROM THE BLACK FACE OF THE IPC TO THE ZERO MARK ON THE PANEL. *TR

I HAVE 2005 GMC YUKON XL THAT I PURCHASED ON THE YEAR END SALE. SO I HAVE HAD IT FOR ABOUT 1 1/2 YEARS SO FAR. SHORTLY AFTER I PURCHASED IT WHILE DRIVING ON THE INTERSTATE A STONE HIT MY WINDSHIELD. I NOTICED THAT AFTER A FEW DAYS AND TEMPERATURE CHANGES A CRACK STARTED TO GROW FROM IT. THAT IS PRETTY TYPICAL RIGHT? YES AND NO. YOU SEE THIS IS MY FOURTH NEW CAR AND SIXTH ALL TOGETHER. IN THE PAST I'VE HAD STONES HIT MY WINDSHIELD BUT NO CRACKS. HAVE I BEEN LUCKY OR IS IT SOMETHING ELSE. AFTER A WHILE I STARTING SEEING OTHER YUKONS, ESCALADES AND SUBURBANS WITH MULTIPLE CRACKS AND CRATERS AND ASKED THE OWNERS QUESTIONS. THEY ALL SEEMED TO BE OK WITH IT BUT I'M NOT. I ASK MYSELF WHY ARE ALL OF THESE WINDSHIELDS CRACKED? STATISTICALLY WHAT ARE THE CHANCES OF WINDSHIELDS CRACKING WITH A STONE ON THE ROAD. THE BOTTOM LINE IS THAT I SERIOUSLY BELIEVE THAT THE WINDSHIELDS ARE DEFECTIVE. *TR