View Single Post
Old 09-30-2009, 02:11 AM   #6
WrenchMonkey
Mechanical Animal
- CORE Member -
- Moderator -
 
WrenchMonkey's Avatar
 
Join Date: Feb 2008
Location: Beechmont
Posts: 1,883
Quote:
Originally Posted by jeeptech77 View Post
in a xj the transfercase has what is known as a viscus coupling it is suppost to allow limited slip between front and rear driveshaft
ideally for snow and on pavement use
this is known as part time use

full time operation is when the differential in the transfercase is locked together ( kinda like a spool ) but disenguageable

the older chevy ford dodge had lockouts so the vehicle would not move in part time just like a open diff with wheel off the ground
Close... Just exactly backwards.


The standard XJ case is the NP231. 2WD-4HI-N-4LO.

Engaging 4HI or 4LO locks the front and rear driveshafts together (actually chains them together, whatever...) Great for off-road, not so much on-road.


The optional cases (NP242 et al) have the viscous coupling, and the positions you list: 2WD-4FT-4PT-N-4LO

The 4PT works like the 231's 4HI: Positive engagement.

The 4FT is the one that allows some slip between the 'shafts. Great for on-road, iffy-traction situations.

You already know to use 4LO on the trail.

Robert
__________________
DIRTY DEEDS, DONE DIRT CHEAP
Whatever doesn't kill you makes you stranger
WrenchMonkey is offline   Reply With Quote