The problem with unequal length drive shafts is "torque steer" where
the longer shaft absorbs more torque than the short one, thus steering
the car toward the long side upon acceleration, which, while annoying,
can be corrected by a flick of the wheel.

Jim

On Thu, Sep 3, 2009 at 5:20 PM, Andrew Grebneff<goose1047@gmail.com> wrote:
>> Say what you will about Subaru engineering, they are no less subject to the need for marketing doublespeak; witness their Symmetrical All Wheel Drive.� What the heck�is that supposed to mean?� Are we to infer from that name that other manufacturers' systems are other-than-symmetrical and, if so, what difference does it make?
>
>
> Most FWD cars have transverse engines. To simplify things they have a
> normal engine with the drive taken off the end of the crankshaft; this
> requires the gearbox to be beside the engine ie offset to one side;
> hence the driveshafts are of unequal length. Subaru's boxwers being
> inline, the crank is north-soputh and the trans lies centrally, hence
> symmetrical driveshafts.
>
> Of course transverse-engined cars are designed this way to shorten the
> car too; if the trans was centered behind the engine and driven from a
> midctrank gear or chain, the drivetrain becomes longer, necessitating
> a bigger vehicle (just as front-engined vans are longer per unit of
> cargobay floorlength).
>
> --
> Regards
> Andrew Grebneff
> Dunedin, New Zealand
> Fossil preparator
> Mollusc, Toyota & VW van fanatic
>