Not shifting gears
I have a 2008 Nissan Sentra Base. A few days ago I started
my car and the battery and brake light was on but I thought
I could make it to work. A few miles down the road as I
was pressing the gas my car started slowing down until it
came to a stop. My grandfather put a used battery in and I
put 3 quarts of oil in. Driving back home the gears wouldn't
shift, the RPMs was between 2 and 3 and also making a
whining nosie and couldn't go over 50 mph without the
RPMs going into 3. I hear people telling me my
transmission is slipping and other people are saying I need
a new alternator. If you have any ideas or suggestions
please help me!