I own a 2002 Chevy Silverado 4x4 Ext. Cab and was wondering why when the 4wd
is engaged it seams as if the the rear end is acting like it has a "posi-
trac" or "locker"? It is very noticable on hard surfaces like hard-pack the
rear inside tire of a turn "skips" and digs up dirt. When not in 4wd, and
trying to spin the tires only one tire spins, usually the right rear.
Message posted via CarKB.com
When you are in 4x4 on a hard surface, the rear axle has a shorter
rolling radius than front axle but both are being driven at same
speed. Being that there is no differentail between two axle the rear
axle has to slip because of torque build up. It will slip first
because unless rear is loaded, the front is heavier than rear. This is
why you are not supposed to use 4x4 on hard surfaces because there has
to be some slippage.
Very simple, the axles do not follow same path in a turn. The front
axle takes a longer wider arc than rear axle in a turn. If you doubt
me, drive on a dirt surface or pavement with wet tires that will leave
track on dry surface and measure the length of the tracks in a turn.
The rear track is shorter. In the 70's they made trucks with Full Time
4x4 that had a differentail between front and rear axle and allowed
4x4 operation without bind on hard surfaces. It died out in 80's
because it used a bit more fuel.
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