T56 Viper Speedo Gear 10-Tooth — Original Tremec Part

What does it do?

Located on the mainshaft in the tailhousing area, this 10-tooth gear interfaces directly with the Viper’s hall-effect style electronic VSS, translating mainshaft rotation into the vehicle speed signal that the Viper’s electronics depend on for speedometer function and other speed-dependent systems. The 10-tooth count is specific to the Viper application — other T56 vehicles use different tooth counts calibrated to their own VSS and axle ratio combinations. Using an incorrect tooth count will result in an inaccurate speedometer reading.

When would you need to replace it?

The speedo gear is not a routine wear item. It typically needs replacement when damaged during disassembly, or from debris inside the transmission.