One problem related to transmission shudder has been reported for the 2007 GMC Acadia. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 GMC Acadia based on all problems reported for the 2007 Acadia.
This issue started when I was driving down the road at 35mpg. The Acadia tried to shift into a higher gear but clunked very loudly and jolted the whole car. From that point forward the vehicle was stick in 3rd gear. It wouldn't up shift or down shift. The car limped home but starting on hills or at stop signs was almost impossible. Once I got the car home I checked the transmission fluid. Transmission fluid ok. I then tested the car again by trying to back out of the driveway. The transmission made a loud grinding noise and would now longer move in reverse. I had the car towed from my house to a local trusted mechanic. The mechanic stated that the waveplate failed. He also said that this was a know deficiency in these vehicles and that the transmission would need to be replaced or rebuilt. I had to spend $3950 to rebuild the transmission on a 2007 vehicle with 80000 miles. I would appreciate a reimbursement from gm for this obvious quality problem.