GMC transmissions have a high rate of transmission failures that require complete rebuilds or replacements to correct. The issue is most common in the 2008 Acadia, 2007 Acadia, 2005 Envoy and 1996 Jimmy models, according to CarComplaints.com.
Most owners who experienced transmission failures in the 2008 GMC Acadia received no prior warning that the transmission was going to fail, such as finding it difficult to shift gears days prior. Out of 35 complaints of transmission failures on CarComplaints.com for this model, 28 people had to replace their transmissions to correct the issue, as of April 2015. The replacement costs over $3,700 on average. Similar to the 2008 model of the Acadia, owners of the 2007 model did not experience transmission shifting issues until the day the transmission failed, and the average cost of repair is over $2,800. Failure typically occurs after the odometer reaches 75,000 miles.
Owners of the 2005 GMC Envoy noticed their transmissions having issues accelerating before failing. One owner stated that the mechanic discovered burning transmission fluid. Another owner stated that GMC covers the cost of replacement so long as the vehicle is under warranty.
One owner of the 1996 GMC Jimmy experienced two transmission failures with a single vehicle. The original transmission failed at 90,000 miles, and the cost to repair amounted to over $2,200.