84 4kq locking differentials

[Huw Powell]

> Why does the selector switch on my 84 4kq lock the front differentials 
> first?  If I switched the vacuum lines to lock the rears first would 
> that harm the quattro system?.  If I drove with only the rear 
> differential locked would that work.

It makes sense to me - before locking the rears to each other, you'd 
prefer to simply keep the front and rear in sync (meaning you have to 
spin two wheels, not one, to be "stuck").  That would be the "going down 
the road" option - center locked only.

Then in a real jam, you go further and lock the rears, making it so that 
three wheels have to spin for you to be stuck.  Not a good way to drive, 
however, unless you are in really low traction situations.

Analogizing to the next generation, with the automatic "torque sensing" 
center diff, the car takes care of the middle for you, hopefully at the 
right times, and the rear can be locked manually, but undoes itself at 
15 mph.

By the way, just for clarification, you aren't locking the "front" 
differential - it's the center one.  The front diff. can't be locked.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/