I am using a H22A automatic in an offroad project. It is geared low due to the final drive is driving 3.50-1 differentials. When I am traveling 40mph, the transmission thinks it is moving about 150. What is the best gadget to use to slow down the sensor about 3.5 times.

 

How did you change the gear ratio in the auto diff?
First I'd see how the speed sensor works mechanically. I know that the speed sensor works on pluses aka square waves via the ECM

 

they make products that will do what your looking for. One of them is called the Speedo Healer if i remember correctly

 

http://www.speedohealer.com/eng/order.htm

Yeah that's cool didn't know it existed.