A transmission main shaft centering device is provided for use between a transmission input shaft and the main shaft. The centering device includes an axially moveable support member having an axis that is substantially coaxial with an axis of the input shaft. The support member is biased into engagement with one of the input shaft and the main shaft to maintain the main shaft substantially coaxial with the input shaft. The support member may include a first engaging component and one of the input shaft and the main shaft may include a second engaging component. The first and second engaging components mate to maintain the main shaft substantially coaxial with the input shaft.