There are 4 owner-reported powertrain & transmission complaints for the 2005 Hummer H2in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
The contact owns a 2005 Hummer H2. The contact stated that while parking in the mountains, the vehicle was in the park position, and it unexpectedly rolled and stopped at a boulder. There were no warning lights illuminated. The door hit the driver and knocked him to the ground, and he sustained an injury to his head, but medical attention was not provided. Another person on an ATV provided a jump start, but the vehicle failed to restart. The contact walked several miles to get assistance. The contact was able to view YouTube and replace the part. The contact stated that the transmission shifter cable had failed. There was a hole in the shaft connected to the transmission to the C clip. The local dealer was contacted, but the vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 111,400.
WHILE TRAVELING ON THE MAIN ROADS THE SPEEDOMETER INTERMITTENTLY MALFUNCTIONS THEN DROPS TO ZERO, WHEREAS I'M LITERALLY UNABLE TO DETERMINE MY SPEED THIS SEEMS TO OCCUR WHEN THE ENGINE WARMS UP AND I BEEN DRIVING FOR BETTER THAN A HALF HOUR.
TRANSMISSION STICKS IN 3RD. GEAR. DISTRESSED ENGINE ON TAKE OFF. ONLY SWITCHES IN AND OUT OF 2ND AND 3RD GEAR MANUALLY. GM DENIES WARRANTY ON TRANS. STATES TRANS. MALFUNCTION DUE TO OVER STRESSING CAUSED BY AFTERMAKET SUPER CHARGER PURCHASED BY OWNER. *JB
2005 H2, PURCHASED 10/2004 THERE IS A NOISE THAT CANNOT BE LOCATED AND REPAIRED. SEWELL CADILLAC, DALLAS, TEXAS REPLACED THE FRONT DIFFERENTIAL (IT HAD METAL SHAVINGS IN IT), REPLACED REAR SPRINGS OBSERVING THEY WERE OVER EXTENDED, BUBBLED AND WARPED. THE CAR IN TWO SEPARATE REPAIR TICKETS HAS BEEN IN THE SHOP 7 DAYS EACH TIME FOR A TOTAL OF 14 DAYS. IS DOESN'T APPEAR THIS PROBLEM CAN BE FOUND OR FIXED. THERE IS A "DRAGGING" NOISE UPON ACCELERATION BETWEEN 20 - 40 MPH. IT IS VERY UNCOMFORTABLE HEARING THIS NOISE. MY NEIGHBOR HAD HER WHEEL COME OFF OF HER 2003 H2. I WAS REQUIRED TO FILL A BLANK SO I CHOSE POWER TRAIN ONLY BECAUSE IT SEEMS CLOSEST TO WHAT IT MIGHT BE, I'M NOT SURE. SEWELL KEEPS TRYING TO FIX THE PROBLEM, JUST UNSUCCESSFULLY.*AK
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026