I have a 2005 Nissan Maxima 3.5 SE and sometimes when I am driving it for a while basically running errands and it gets warm, I put it in reverse or drive and it takes a second or two to go into gear. I’m sure it’s something with my transmission but it doesn’t slip or I don’t have any other symptoms of transmission problems. It only does this if I have been constantly putting it in reverse or drive while running errands.
You need to take it in where someone can check the transmission fluid level and condition. A lot of city driving is hard on transmission fluid. Just as it is on engine oil.
I took it to a Nissan dealership to have all that checked and they are trying to sell me a new transmission which I don’t think I need one because of not having the symptoms of needing a new one. Although they serviced my transmission back in December and that stopped the problem but it later came back with the same problem. When I took it back that is when they said I needed a new one and the fluid was no longer pink looking like it should be but gunky.