While driving transmission made a noise, slipped, and then locked. When this occurred vehicle stopped accelerating. Vehicle was towed to a dealership, who replaced the sun seal and pins that sheared off. The failure recurred 3 times in which the same parts were replaced. The cause of the failures was undetermined.

- Cumming, GA, USA

My 2002 Chevrolet Silverado ext cab 4X4 transmission failed at a repair cost of $1400. It had 42,800 miles on it. Final warranty work(36000 miles) was done about 2 months ago. General Motors says they won't help me cover repair costs because I traded the vehicle for a new GMC (I no longer had confidence to keep this vehicle since the transmission should have been trouble free for sure for 100,000 miles and I was afraid it could happen again 40,000 miles later. I tried taking good care of this vehicle). Whether I kept the vehicle or not is beside the point. I owned the vehicle at the time of the repairs and expected some financial help from GM.

- Grand Forks, ND, USA

Allison automatic transmission nsbu switch failure. Two other people in shop with same problem at same time. Dealer service writer and other mechanics state problem is very common and part should be recalled.

- Parker, CO, USA

Consumer complained about a transmission problem. The transmission would only move into third gear. The neutral safety switch was defective as per owner. The consumer had the switch replaced.

- Vancouver, WA, USA

Loss of reverse and transmission at 54,000 miles. Started out going into 1st and 2nd very hard now this.

- Hampstead, MD, USA

Air conditioner (A/C) line runs over the top of the distributor, causing condensation in the distributor. When this occurs, it results in engine misfiring and vehicle stalling. At 22,000 miles transmission went out.

- Mobile, AL, USA

2002 Chevy duramax diesel with allison transmission engine surging, lunging & dead spots when you try to accelerate or brake. Transmission clunks & also jerks the vehicle. Dangerous in parking areas & when trying to accelerate onto incoming traffic where is often has daily catastrophic failure.

- Ridgecrest, CA, USA

Transmission clunks when decelerating and accelerating from stop. Spline lubed first time and reduced loudness of clunk but within 300 miles noise was back.

- Massena, NY, USA

Loss of reverse, second and fourth gears completely in automatic transmission.

- Concord, NH, USA

The transmission failed twice since the vehicle was purchased. The transmission has been replaced at 10K miles and 20K miles respectively.

- Lorton, VA, USA

Transmission slips during the 1-2 up shift at moderate throttle input causing a distinctive clunk and could be a possible safety concern on two wheel drive vehicles on slippery roads, where as vehicle loss of control could occur when transmission engages. Vehicle returned to dealer twice with concern, one attempt to fix with replacement of transmission output shaft. This did not help.

- Fenton, MI, USA

Vehicle rolled back while in park. Truck was found against the house with the doors locked and still in park. Emergency brake is typically engaged because it is parked on a slope drive but it was found disengaged. While being towed it also rolled while loading onto the tow truck. Again, it was in park with the emergency brake engaged. Vehicle was looked at by two separate service departments with no cause found. Damage was done to the truck and the home but since GM could not duplicate the problem we are responsible for all damages. Will most likely get rid of the vehicle (trading it in at same dealer who sold and serviced it) because we do not feel safe leaving the vehicle unattended.

- St. John, MO, USA

No summary listed for abov evehicle.

- Gonzales, LA, USA

There have been repair attempts none have been fully sucessful. No safety defect listed.

- San Lorenzo, CA, USA

While accelerating from a stop transmission hesitates and then jerks into gear. Dealer has inspected vehicle, but could not duplicate or correct the problem.

- Lafayette, LA, USA

Transmission slips after taking off from a complete stop, causing engine to rev up, transmission clunks into gear, causing truck to lurch forward.

- Manchester, NH, USA

When shifting from first to second gear, and second to third gear, transmission shifts hard. Loud noise from the transmission/ rearend. Occurred after freeway driving repeatedly.

- Fresno, CA, USA

Allison transmission problem: While in overdrive with a towing load going uphill, the transmission will downshift in or out of cruise control, causing the engine to increase speed up to the danger zone of 3300rpm. The vehicle was checked by the listed dealer, whom noted that General Motors has no correction available for the downshifting and engine racing in overdrive. This complaint is to register this observation with my vehicle.

- Xenia, OH, USA

With cruise/speed control set/on transmission repeatedly downshifts below 4th. And 3rd. Gears into 2nd. And 1st. Gears causing erratic acceleration, excessive vibration and fatally high engine R.P.M. revving at highway speeds.

- Fairmont, WV, USA