How does 4x4 really work

I have a 99 gc with quadratrac II and have noticed that the full time does
not perform well form a cold start.
I have assumed that the "fluids or hydrolic system" needs to warm up to
operating temp before the full time
will work well. After driving only a mile I see a marked improvement in
traction. At the same time if I shift
into part time I recieve solid traction even from a cold start. All of this
is when starting cold from my driveway
turning onto a snow covered 7% grade road. To test this I have tried
driving out of my driveway immediatly
after returning home in full time.

jimo


"Richard" > wrote in message
...
> this is curious...'(quote the posted article)'...
>
> "Finally, a full-time 4x4 system like comes on most Grand Cherokees and
> some
> Cherokees and Liberties 'couples' the front and rear axles together, but
> they are not mechanically locked together like a part-time 4wd system
> does.
> The coupling can be done via either a differential (just like what is
> between the left and right tires) or a fluid (viscous) coupler. The
> benefit
> to a full-time 4wd system is that because the front and rear axles are not
> mechanically locked together, the front and rear tires/axles can rotate at
> different rpms from each other. This allows a vehicle with a full-time 4wd
> system to drive in 4wd "full time" on a paved road without problem since
> there is no 'wind-up' problem to harm the drivetrain."...
>
> I was driving in some fresh snow today, packed/loose mixed... and as
> usual,
> I used my "Full Time" 4WD, but I (unusually) was slipping a bit on a very
> steep hill and sharp corners and tried "Part Time" and it seemed to work
> better. So what gives? I thought "Full Time" was supposed to be better. (I
> would never use the "Part Time" on dry pavement)
>

This is an excellent explanation of 4x4
http://auto.howstuffworks.com/four-wheel-drive.htm

also make sure to read up on differentials work:
http://auto.howstuffworks.com/differential.htm

HYFTH,
Chad

"Patrick" > wrote in message
...
> Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was on
> full time
>
> The rear right (passenger) wheels was spinning and it feel it was the only
> wheel really trying to get out, i know the 4x4 is working (Light on and
> feeling while doing u-turn ) but why i did not see the front wheel
> spinning while the gc was on Reverse , I was outside with the truck engage
> looking at the truck spinning. !!!!!
>
> I tried part time and no much luck. Got out of there with time and
> patience REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same ?
>
> thanks
>
> Pat
>
>