where is the vehicle speed sensor on 2000 Nissan Frontier

Where on the transmission on the 4 wheel dive model is the speed sensor and does anyone have pics my dad is 77 and his went out and its bad enough the part at the local store is 200 bucks i want to fix it for him.

Asked by for the 2000 Nissan Frontier
What is worse than having to buy a $200 sensor is replacing a $200 sensor that is not needed. Are you sure that is the problem?