2008 GMC Acadia: harsh or hard shifting

Filed Jul 30, 2023 · Fuel system, Transmission · AL

Check engine light came on for the TCM. Car has had issues shifting (very rough shifting) and the manual shift option does not work. Was told the TCM had to be replaced. Attempt was made to replace it with a refurbished TCM but that couldn't be programmed to the car. Was then told I would have to buy a brand new one, which is very expensive, and that there was no guarantee that would fix the problem. Car can not be driven over 20mph without risking burning up the transmission. Car also jerks forward very hard when trying to gently accelerate.

Filed Apr 19, 2018 · Transmission · 106,000 miles · PA

For the past 6-9 months I have been experiencing problems with unwarranted speed shifting, hard shift changes & overall transmission issues. I have had my car to transmission specialists almoat on a monthly basis for these issues. I was told by the specialist that he repairs at least 3 cars of my same make & model per week. He said he is noticing a very common failure in each vehicle. My vehicle has power but the speed & gear shift are huge safety issues, as it is very random & unprovoked. I have been driving on the highway & my vehicle would just stall or shift. I have had to carefully pull over to the side of the road to avoid a major accident.

Filed Nov 7, 2014 · Transmission · 75,200 miles · MO

Transmission. Problem shifting...3rd gear. Vehicle would attempt to shift at 40mph but unable to do so. Engine would rev up then shift extremely hard with a loud clunking noise. Took vehicle to local dealership who informed me transmission would need to be replaced. More cost efficient to replace than to rebuild. No third gear. Transmission should not need replaced at 75,000 miles.

Filed Jul 26, 2014 · Transmission · 58,500 miles · CA

2008 acadia purchased in 2007, transmission intermittently slamming into gear for high speed up and down shift. On dry pavement the SUV will change several MPH well within a second. My concern is that this is potentially dangerous while driving in inclement weather. Especially on snow/ice! I am taking the SUV to the dealer on monday for a diagnosis. I suspected an internal clutch problem or valve control problem couple of weeks ago. The problem is progressively getting worse. After reading online I found that this is a common problem with this series of transmissions starting after 47k. I wanted to add my concern. My car just passed 63,000 miles. I truly believe this is a potential safety hazard. Several things would have to happen at once (ie let off the accelerator, accelerate, brake, and be on wet or ice roads). The shift is intermittently hard during any of these changes in acceleration causing a potentially dangerous condition.

Filed Jun 12, 2014 · Acceleration, Transmission · 133,000 miles · GA

The transmission had been hard shifting from 3rd to 4th for about 200 miles. At 25 MPH while turning through a very busy intersection the engine revved shifted through what felt like every gear, the car lost acceleration power; going from 25 MPH to 10mph. Parked the vehicle. Restarted to find that only first and second gears worked and the check engine light illuminated. During the 200 previous miles of concern; I had heard a faint whine during acceleration. The first time any trouble occurred the vehicle was stopped behind a school bus loading and while I applied the brake (still completely stopped) the car lurched forward. I immediately shifted to neutral, not wanting to rear end the school bus.

Filed May 14, 2014 · Steering · 95,000 miles · VA

I had been hearing a clunking sound while turning the wheel at lower speeds lately, but on the way to my mother in laws house, with our one year old son in the car, the power steering felt like it went out. We took it to the dealership hoping it was an inexpensive fix, but were not so lucky. This repair will set us back about $1,500! Ridiculous! I looked online and was shocked to see so many issues with the steering of this vehicle. I truly love the look and ride of my acadia, but safety always comes first when it involves my family.

Filed Dec 2, 2013 · Transmission · 51,000 miles · CA

The transmission would not shift into third gear. Took to dealer. They were aware of the problem and "offered to help" by discounting the price of rebuilding the transmission. The transmission is still not right. Shifting is poor and clunky.

Filed Dec 2, 2013 · Transmission · 68,270 miles · FL

The transmission in our 2008 acadia has begun slipping and first gear shifts engage with a very noticeable clunk (thump); there is also a delay when the car is shifted into drive (~3 to 5 seconds); gm needs to perform.

Filed Nov 2, 2013 · Steering · 85,000 miles · IN

At low speed, power steering seemed to go out while in parking lot. The steering became very difficult to manage with a loud clunking noise coming from the front end. Shutting off and back on, steering returned to normal. Took it in for service at gm dealership in evansville, in for diagnosis and response was that the power steering pump, fluid and steering rack needed to be replaced. Investigation online turned up information that this is a relatively common occurrence but gm would not do anything about it as it was outside of warranty.

Filed Sep 24, 2013 · Acceleration, Transmission · 63,000 miles · OR

Vehicle has a delayed shift into 3rd and 5th gear, with a vibration felt in those gears. Found codes p0717 p0716 for input speed sensor on transmission. It is believed the vehicle has a broken 35r wave plate and need to tare down to inspect or replace transmission at only 63,000 miles. Extremely common problem on these vehicles (please refer to gmc acadia forums online everywhere for other victims).

Filed May 6, 2013 · Transmission · 84,000 miles · WI

There was a "clunk" upon acceleration from stopped, soon after vehicle would not move. Wave plate was destroyed in transmission causing a need to be rebuilt, as so many, if not all others in 2007-2009 gmc acadias have been. Out of pocket cost to me is $3,500 because gm used a $2 part instead of an $8 part. This is an huge safety issue that is stranding people, mothers with children, in dangerous situations, all the while, gm is well aware of the problem and solution but refuses to step up and take responsibility for it. There needs to be a safety recall for this issue.

Filed Jan 29, 2012 · Electrical, Steering · 48,500 miles · UT

Car will not shut off after removing key from ignition takes a minute for car to shut off car would not start next morning intrunent panel shows multipal problems have read online consumers with same problems who is responsible for this issue.need help have had vehicle fpr three weeks was not told by dealer abought problems with electrical have printed all other complaints on line and will show to dealer I would hope that gmc does not approve with these actions.also have problem with sreering it makes a loud clunking sound when turning steering wheel this coul be a serious safety issue to my family.