James 
2013 Nissan Altima Sedan 2.5 4dr Sedan (2.5L 4cyl CVT)
Listen up everybody it's not the CVT transmission
 Nissan is pulling a quick one on everybody by saying the problem you're having is your transmission. Think about it people, with the car shutting off you have to remember transmission will not affect your car starting the problem is the alternator. CVT transmissions are extremely sensitive to the electrical current it gets and the alternators are faulty causing the car to rumble and shudder now Nissan would rather tell you it's the transmission because it only has a 36,000 mile warranty and the alternator has 100,000 or whatever it has don't know the exact mileage but much more than the transmission tell them to replace your alternator and it will fix the problem I had the same problem with mine. Put in new alternator and its driven like a dream ever since. Because mine started acting up right after the 36,000 mile transmission warranty and they said I had to replace the transmission luckily I bought my car through Carmax who has an excellent warranty and they took the car I told him what I thought about the alternator they looked into and presto so I drop my car at Carmax the mechanic there drove it to a Nissan dealership told him to put a new alternator in doing great ever since don't let Nissan tell you it's not the alternator they just simply want to say it's the transmission because chances are most of you are outside the 36,000 mile warranty and what they'll do is put a new transmission in and it will run better for a little bit but that alternator will chew the transmission apart again this is my third post about this I posted every few days to keep her on the top of the review list hoping to help people good luck guys. And I have a friend who works for Nissan so I was able to confirm this that it is the alternator and some of the technicians purposely keep their mouth closed because they want to get paid for doing the work on the transmission a lot of the dealerships don't pay by the hour they paid by the job so the technicians are the ones [non-permissible content removed] us along with Nissan.