EP0321434A2 — All-wheel drive vehicle power train

USPTO Abstract

A drive line assembly and mounting arrangement for converting a front engine front wheel drive vehicle to an on-­demand four wheel drive system. The vehicle rear axle (20) is adapted to be selectively driven by means of a viscous fluid coupling (17) positioned intermediate a forward angled universal-­joint drive line assembly (16) and a rear torque tube enclosed longitudinal propeller shaft assembly (18, 44). An overrunning clutch (19) is rigidly connected intermediate a forwardly extending neck portion (24) of the rear axle drive housing (23) and the torque tube (44) defines a composite torque tube structure. The overrunning clutch is adapted to be locked for a transmission of torque during normal driving. The rear axle drive housing is sprung from the frame (62) by a pair of transversely aligned isolation mounts (105, 106) while the composite torque tube is resiliently secured by a bracket support (58) adjacent its forward end. The composite torque tube provides an extended lever arm of a predetermined length that oscillates in a vertical plane about the transverse axis of the pair of rear mounts whereby the reaction torque vibrations from the rear axle drive imparted to the forward resilient bracket support are effectively dampened.