A method and unit for shifting gear in a power-assist transmission; to shift gear, a series of operations are performed in sequence, and each of which must be completed prior to completion of the next operation; for each operation, a predicted time delay is estimated corresponding to the time lapse between the instant the operation is commanded and the instant the operation is actually completed; and the operations are commanded successively as a function of the predicted delay times, so that an operation is commanded before the preceding operation has actually been completed.