Quote:
Originally Posted by AeroModder
In Subarus, cars with automatics have a 90/10 torque split while cruising to offset the dragging of the rear wheels (electronically controlled transmission control unit), but the manual models have a 50/50 (Center differential with a viscous coupling device).
Subaru's All Wheel Drive System - AutoWorld.Com |
I owned an 01 Forester with manual transmission and personally had it apart. The engine (through the transmission) drives the ring gear of the front wheels directly and a jack shaft drives the rear output flange to the rear axle through the viscous coupling. When I disconnected the rear driveshaft and attempted to verify this by crawling up a curb, and by dumping the clutch on flat dry pavement, it behaved like a front wheel drive car with 100% engagement.
Hypothetically if you removed the front axle shafts from the same vehicle and tried to drive it as a rear wheel drive, it would only be able to deliver half of its torque to the drive axle and would likely wear itself out by freewheeling the front flanges any time the engine supplied more torque than the coupling wanted to send the rear wheels (such as acceleration/climbing/etc)