AWD

[A_racing_driver]

So on my 2004 impreza how does the AWD system work? I looked it up and it said its a 90-10 split front to back is that right?

[Fairtax4me]

Auto or manual?

[idosubaru]

do you mean the electronic controls, the 4WD specific components only, the entire system, and manual or auto....and VDC and later models are different too....

 

http://www.ultimatesubaru.org/forum/topic/102083-best-write-up-on-how-a-transmission-works/

 

http://www.ultimatesubaru.org/forum/topic/48020-awd-vs-4wd-can-someone-edjimecate-me/page-2

 

http://www.awdwiki.com/en/subaru/

 

http://www.manchestersubaru.com/subaru-symmetrical-all-wheel-drive.htm

 

http://www.awdwiki.com/images/subaru-mpt.jpg

[A_racing_driver]

Auto or manual?

Auto

[ccrinc]

Generally speaking, all post-Loyale automatic Subarus operate in 90-10 mode under normal driving circumstances.  When cornering, slipping, driving in bad weather, etc. is when the AWD features kick in, taking traction from whichever wheel has the least "grab" and transferring to a different wheel to keep the car stable.  (You know, the old "transferring traction from the wheels that slip to the wheels that grip" advertising line.)

When conditions return to "normal" the 90-10 split returns.  Best AWD system in the world, IMO. 

[Fairtax4me]

The front wheels are driven all the time on the automatic. 100% engine power is delivered to the front wheels no matter what.

 

The rear wheels are powered via a clutch pack in the tail section of the trans that varies the amount of power delivered to the rear by varying fluid pressure on the clutch pack. The amount of fluid pressure determines how much slip of the clutch pack is allowed, or if the pack needs to be locked down to provide 100% drive power for the rear wheels as well.