Since buying the car new, there has been a vibration/shudder coming from under the vehicle when slowly accelerating. The dealer has looked at the problem twice and has been unable to find the source of the problem, even though a tech has heard the vibration while riding with me on a test drive. I'm concerned about this because powertrains that are functioning properly should not make this noise.

- Plymouth, MN, USA

Approximately two weeks after purchasing my brand new 2013 Altima 3.5 S the car developed a shudder and vibration when I would accelerate slightly. It also occurred going up small hills, and when I would come to a complete stop then pull off (for instance at a red light). After noticing this, I scheduled an appointment with the dealer, and we did a test drive in hopes of mimicking the issue. The mechanic advised me that this was normal for a cvt engine, and that everything was fine. I wasn't quite convinced, but I wanted to trust his opinion, since this was my first time driving a car with a cvt engine. However, a few weeks passed and the shudder and vibration got worse. The car even jerked forward once when I was pressing on the brakes. This prompted me to schedule another visit with the dealer. This time the same mechanic from the first visit and the manager rode along with me. During this test drive the manager felt the sudden shudder, once we came to a complete stop and slightly accelerated. This prompted them to replace my transmission, not even 30 days after my purchase. I picked my car up from the dealer on 12/7/12 after they changed the transmission and the car drove perfectly fine. The bad news is that now the car has developed the same shudder and vibration even more now. I will be calling for another appointment tomorrow, because something has to be done about this. It's very dangerous, especially when this happens and you have another car riding directly behind you. ## VIN failed

- Athens, GA, USA

Altima 3.5 transmission has a severe shudder when accelerating normally at about 15-25 mph. This is intermittent but serious as it results is severe shock to the drivetrain. This was not present when new and has been increasing in severity over the last 1000 miles. The dealer says that Nissan engineers claim that it is "characteristic" of the 3.5. this is not true as it was not present when new and is constantly getting worse. It will probably soon result in transmission damage or complete failure which could be a serious safety issue.

- Brooksville , FL, USA

On October 4, 2012 I purchased a 2013 Nissan Altima 3.5 sl. It was obvious almost immediately that there was a problem with the transmission. Upon taking off from a stopped position the first shift of the transmission is very hard, especially under light acceleration. Two weeks after purchasing the veh. With approx. 400 miles on the odometer I was pulling away from a stop when the veh. Started shuddering and shaking violently before shifting into gear with a hard bump. This incident lasted approx. 2 seconds. For the next 700 miles or so the shuddering and shaking occurred six more times. I took the veh. Into the Nissan dealer where it was purchased and after driving it they advised that they could not duplicate the problem. Over the next 500 miles the incidents became more often and at times more severe, one incident lasting for several seconds before finally shifting into gear. On December 5, 2012 the veh. Was returned to the dealership. I spoke with service manager explaining the problem and my concerns of maybe the veh. Stopping in the roadway during one of these incidents and being rear ended. This time the service manager rode along with me and drove the veh. Duplicating the problem several times. The engineers at Nissan was contacted by the service manager and they confirmed that there was a problem with the transmission software on the V6 Altima, however they had no fix for it at this time.

- Covington, GA, USA

The contact owns a 2013 Nissan Altima. The contact stated that the vehicle would go into neutral while idling and would slam into gear when attempting to accelerate. The contact mentioned that immediatelly after the failure the vehicle stalled. The vehicle was taken to the dealer who has not been able to diagnose the failure. The failure mileage was 500 and the current mileage was 700.

- Pace, FL, USA

The vehicle surges at around 25mph. It cuts out, slows down for a couple seconds, then jerks forward. When it jerks forward, it slam hard like it is doing damage to the transmission.

- Providence Forge, VA, USA

The problem began with the transmission locking up or shuddering going down hill, throwing the vehicle and me forward. Ever been on a golf cart going down a hill where the governor throws you forward? multiply that by about 5 and that's what you get. It has progressively gotten worse, to the point where it actually causes the wheels to stop and "chirp" on the pavement. Now, it even happens on relatively flat areas and, going up some hills, the transmission just about gives out. It's a safety issue for several reasons: (1) locking up going down a hill is unsafe if someone is behind you, (2) the severity of it could cause you to lose control of the car, (3) losing power going up a hill could cause you to be rear-ended. Nissan has been slow to respond even though other people have had the same problem. My dealer says that they searched Nissan's "tech talk" across dealers and found nothing. Do a google search on "Nissan deceleration shudder or lockup" and you'll find lots of folks with the same problem. Very unfortunate for an otherwise great car. They need to identify the problem and recall some or all of the 2013S.

- Mobile, AL, USA