I have a 96 Nissan Altima with manual transmission. Today when I was driving it wouldn't let me shift from 1st to 2nd gear. It would only let me get it into third. Once in third it wouldn't let me get into any other gear. The gear stick is physically stuck in third gear and will not move. The car remains in third. The clutch will release, taking it out for gear, when its depressed, the car will roll backwards. Any help would be appreciated.

This could be caused by a number of things.

First, determine if the problem is your shifter or inside the tranny. Lift the car, unbolt the striking rod (shift control rod) from the u-bracket on the tranny. Now insert a screwdriver thru the holes of the u-bracket and use it like a handle to push/pull/rotate the bracket through the h-pattern. If it's in 3rd now, then use a heavy hammer to gently tap the bracket back into neutral and further into 4th. If it's willing to do that, then your problem is just something between the bracket and your shift knob.

If you can't shift it that way, you have an internal problem in the tranny. It could be broken detente springs, damaged shifter gates, or something else broke loose and is now blocking the shifter mechanism from moving. By chance has your speedometer / odometer stopped working lately? Unfortunately to solve this problem you need to drop the tranny and have it opened up for repair.

Dave