NHTSA Complaint #763187 — 2001 GMC SIERRA

THE TRANSMISSION VIOLENTLY SHIFTS INTO GEAR UPON ACCELERATION FROM A STOP OR SLOW SPEED. THIS PROBLEM HAS OCCURRED AS MANY AS TEN TIMES SINCE THE ORIGINAL DATE OF PURCHASE. ON MAY 4TH IT OCCURED SO VIOLENTLY THAT THE PASSENGER IN THE REAR HIT HIS HEAD ON THE REAR WINDOW. IN THIS INCIDENT THE SHIFT WAS SO HARD THE REAR WHEELS LEFT THE GROUND(ALL 4) AND THEN THE TRUCK LURCHED FORWARD. THIS IS A SERIOUS DEFECT THAT COULD CAUSED HARM TO THOSE INSIDE THE TRUCK AND COULD HARM OTHER DRIVERS OR PEDESTRIANS. THE TRUCK SEEMS TO GO TO A NEUTRAL OPERATION EVEN THOUGH YOU ARE IN DRIVE THEN WHEN THE RPM"S ICREASE TO ABOVE 2,000 IT SUDDENLY SHIFTS. I HAVE TAKEN THE TRUCK TO THE DEALER 5 TIMES AND RECENTLY COMPLETED ARBITRATION TO TAKE THE TRUCK BACK. THE GMC REPRESENITIVE CLAIMED THAT THIS WAS NORMAL FOR A "HEAVY DUTY" TRANSMISSION SUCH AS THE ALLISON. THE BEST DISCRIPTION OF THE PROBLEM IS IT FEELS AS IF YOU HAVE BEEN HIT FROM THE REAR BY ANOTHER VEHICLE AT 15-20 MPH. *AK