The Vehicle Speed Sensor (VSS) Relocation Kit is designed for Ford Broncos or F-series with E4OD transmissions paired with the BW1356 transfer case with a bolt on flat flange.
This is needed when upgrading your stock 8.8 rear end to a stronger axle, like a 9", since the stock location of the VSS is on top of the rear axle.
This relocation kit utilizes your stock tone-ring sensor, which is relocated to the rear of your transfer case.
The supplied VSS tone ring has magnets to signal your stock sensor, which conveys the pulse to your vehicle’s ECU.
Without the vehicle speed information being present at the ECU, the transmission won’t shift properly. | 
