Nissan Maxima: '92 Crazy Odometer

Hi, when I turn on my car and start driving the odometer goes to + 140 mph
and stay there about 10 or 15 minutes (the real speed is about 35 - 40
mph), after that, it return to normal but sometimes it hits again the top
of the scale, it continues doing that for about 10 minutes more, so I lose
my odometer for about 25 minutes. I really need to fix the problem asap.
Other thing, it sometimes shows an incorrect speed (45 when i'm driving at
35). HELP!!!!. Thanks. Jonathan.

fenix_jn wrote: 

I'd check the speed sensor (on the trans).