a vehicle engine is connected with a belt - type continuously variable transmission via a clutch . the transmission transmits torque via a belt between a pair of pulleys , and varies the transmission torque according to a supply of oil pressure . the clutch engages by means of oil pressure supplied as a shift lever is changed over from a neutral range to a drive range . an oil pressure supplying device supplies the oil pressure required to transmit torque between the belt and the pulleys , and the oil pressure for engaging the clutch . slippage between the belt and the pulleys is prevented during engagement of the clutch by restricting the output torque of the engine over a predetermined period of time .