Abstract: An improved power takeoff arrangement for a vehicle four-wheel drive transfer case having high, neutral and low positions. The transfer case input shaft has a integral gear member defining the sun gear of a dual planetary gear assembly having its carrier rings grounded to the transfer case housing. A planetary annulus gear, formed with an inboard axial extension concentrically surrounding the inboard carrier ring, is driven by dual planet pinion gear sets journally supported between the carrier rings. The annulus gear inboard extension is formed with external helical gear teeth adapted to mesh with a power takeoff input gear accessible through an aperture in the housing side wall. The arrangement enables power at a constant relative speed to be transferred from the transfer case input shaft to the power takeoff gear in any of its three positions while obviating unbalanced loading of the dual pinion planetary assembly.

Abstract: A dual planetary gear reduction assembly for a two-wheel/four drive vehicle transfer case mechanism providing an exact two-to-one gear reduction ratio during full-time four wheel drive operation. The dual planetary is uniquely designed to provide a grounded carrier supporting inner and outer sets of planetary gears operative to rotate an ungrounded annulus gear and a meshing annulus plate in the same direction as the input shaft. A sun gear, having a predetermined number of helical teeth, is formed on the input shaft while the annulus gear has a predetermined number of internal teeth exactly twice the number of sun gear teeth. A clutch collar is internally splined on the output shaft and has external splines operative, when the collar is shifted into its low-range mode, to engage internal splines on the annulus plate and drive the transfer case output shaft at the two-to-one gear reduction ratio.

Abstract: An add-on overdrive unit for location on an extended output shaft of an automatic transmission. The unit includes a planetary gear set connected by means of its annulus gear to an outer face of a one-way clutch. The one-way clutch inner face is concentrically interconnected to the transmission output shaft. An hydraulic piston operates a first direct-drive clutch pack and a second overdrive clutch pack. The piston is normally biased to its non-pressurized failsafe direct drive position by a compression coil spring. As a result the direct drive clutch pack is engaged causing the planetary sun gear to be locked to the annulus gear providing a one-to-one direct drive speed ratio to the overdrive output shaft via the engaged one-way clutch outer race. Upon the piston being pressurized the overdrive clutch pack is engaged and the direct drive clutch pack is released grounding the sun gear to the overdrive case.

Abstract: A dual planetary differential for a two wheel/four wheel drive vehicle transfer case mechanism providing an unequal torque split between the front and rear wheels during its full-time four wheel drive operation. The dual planetary gear set may be shifted by means of a mode clutch to provide either four wheel drive with full-time differentiation between the front and rear wheels or a part-time four wheel drive mode wherein the dual planetary is in a locked-up condition. The first and second sun gears of the dual planetary have unequal diameters with differing numbers of teeth such that, for example, proportionally more torque is transferred to the rear wheels than the front wheels. The sun gears have complementary frusto-conical web portions arranged in a juxtaposed compact manner within the transfer case.

Abstract: A viscous fluid rear axle coupling apparatus for a front engine vehicle having a front transaxle drivingly interconnected to its front pair of wheels. The viscous coupling apparatus includes power transfer means adapted to convert the rotation of the vehicle's longitudinal propeller shaft into rotation of an outer drum of the apparatus about a transverse axis. The outer drum concentrically surrounds a pair of coaxial right and left inner drums enclosed in a housing chamber filled with viscous fluid. Each inner drum is drivingly connected to respective right and left rear wheel output shafts extending transversely outboard therefrom. Each inner drum has a set of inner plates interleaved with a single set of outer plates of the outer drum. The apparatus functions as an interaxle and limited slip differential during four wheel drive as well as a conventional differential allowing the rear wheels to rotate different amounts during its two wheel and on-demand four wheel drive modes.

Abstract: A dual bevel gear differential transaxle assembly for a front transverse engine vehicle with front and rear pairs of road wheels providing a part time on-demand four-wheel drive system. Interaxle and front wheel bevel gear differentials are aligned on a transverse axis. The differentials are connected by a side gear shaft and inner and outer side gear sleeves concentric about the side gear shaft. The interaxle differential achieves front axle to rear axle differentiation while the front wheel differential provides differentiation for the front pair of road wheels. The dual differential transaxle assembly includes viscous fluid clutch means providing an automatic limited slip condition of the interaxle differential when there is a predetermined difference in speed or rpm between the front and rear pair of road wheels.