From carnuck@hotmail.com Tue Jul 29 23:36:45 2003
From: Jim B <carnuck@hotmail.com>

A: The 228 has open carrier in it like a non-posi rear end.
The NP229 has a viscous coupler (read silicone oil that makes it like a clutch
between some plates with holes in them inside a heavy duty plastic bag) which
is like a very light duty posi-trac rearend center section (turned sideways.
Instead of controlling the 2 wheels in a rear end, it controls the slippage
between the front and rear driveshaft) It works fine till there is too much
slippage (ie: The front axle vacuum motor disengages on the 'late 82 to early
'86 rigs with the pin on the dash switch to keep you from engaging 4x4 easily
while driving, because you're not supposed to! ) If there is too much
slippage, it overheats and the "bag" that keeps the oil in falls apart and it
is temporarily open like the NP228, until the silicone oil destroys all the
bearings and seals in the transfercase, and chews up the gears as it is not
very lubricating. (It's just slightly better lubricant than liquid sand!)
   The NP208 is like a Lincoln Locked rear axle. It's solid shaft front and
rear with no slippage. On dry, good traction pavement, it winds up like a
spring because the front and rear tires turn at different rates of speed on
corners, and any difference in wear from front to back or even tire pressure
will cause a difference in rotation of the front and rear shafts. (It also
feels funny when driving around corners, like it's "hopping") The NP229 was
made to alleviate that, but who needs 4 wheel on good surfaces? <G>

From: "Faith Jeff" <Jeff.Faith@rxsol.com>
Subject: fsj: why a 228 ?

so why is the 228 favored over a 229 xfer case?

- -jeff