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4 wheel drive part time vs full time?

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Old Oct 29, 2011 | 08:33 PM
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Default 4 wheel drive part time vs full time?

Hey guys on my 01 cherokee i have the np 242 transfer case. I was wondering for snow driving should i put it in 4 pt time or 4 full time? And when im offroad in mud which should i use? Thanks guys
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Old Oct 29, 2011 | 08:37 PM
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I have only had one XJ with the NP242 and I believe the Part Time selection would be for OFF ROAD only and the Full Time would be for on road. I believe it was told to me that the Full Time was more like an "All Wheel Drive" selection. I hope this helps and I am sorry if I have this backwards. If anyone else can verify this please do! Good Luck!!
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Old Oct 29, 2011 | 10:31 PM
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as I understand it, in full time 4 wheel drive the transfer case will act like a limited slip your power is distributed approximately 60/40 so it does not bind. also I believe the 242 is weaker than 231. also full time can be used anytime you like.
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Old Oct 29, 2011 | 10:39 PM
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yup, lucifer's got it right.
full time for snowy roads and part time for off road.

don't worry about which t-case is better or stronger. you won't break your 242.
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Old Oct 29, 2011 | 10:44 PM
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The "4" means it is a stronger case...

Fulltime for crappy roads.

Last edited by 89Laredo; Oct 19, 2012 at 01:43 AM.
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Old Oct 29, 2011 | 11:11 PM
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The green places are for on road (2WD and 4Full) while the orange places are for off road (4Part and 4Lo).
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Old Oct 29, 2011 | 11:36 PM
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I have a 242 as well, all the above is correct. Best thing to do is try them all and see what the differences are for yourself, best way to learn it. The lables are counter intutitive.
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Old Oct 30, 2011 | 01:44 AM
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Thank you guys for the info. Would it be bad for me to use part time on the roads? And what about full time offroad? Last time i went wheeling i used full time offroad? Is that bad?
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Old Oct 30, 2011 | 07:48 AM
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Originally Posted by eugnton
as I understand it, in full time 4 wheel drive the transfer case will act like a limited slip your power is distributed approximately 60/40 so it does not bind. also I believe the 242 is weaker than 231. also full time can be used anytime you like.
No 60/40 distribution as it has an open diff. It is the best to useon smowy roads, especially if you're driving where there are patches of snow then bare pavement.

The original AMC Eagles and early Jeep XJs had a viscous limited slip in the T-case which was excellent in the snow and worked somewhat as you described. They dropped it due to cost in about 1984 on the Eagles, and about 86 on the XJs.
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Old Oct 30, 2011 | 07:51 AM
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Originally Posted by MudMann94
Thank you guys for the info. Would it be bad for me to use part time on the roads? And what about full time offroad? Last time i went wheeling i used full time offroad? Is that bad?
Not BAD to use PT on the roads, but usually not necessary. It's what the guys with PT have to do.FT is smoother, doesn't bind, and can be left in all day forever if you want. Only your fuel mileage would suffer.

Off-road where there may be one wheel coming off the ground or getting real light, PT is better. Cruising dirt roads that are slick or real loose, FT works just fine.
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Old Oct 30, 2011 | 08:03 AM
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Originally Posted by Defiance665
The "4" means it is a stronger case..

where do you get that from? those numbers appear to be the last number in the case.
example:
231/241 are part time case.
242 is a full time case.
247 is (likely) the geo case.
249 is the viscous case.

so in all reality, the 231 and the 241 are the stronger cases. 241 is found in the jeep rubicon.

but anyway. that's not the question here.

to the op, no worries using full time off road. it would be fine, just try to stay away from using part time on road. unless you only use it for snow covered roads and disengage when you hit dry road. better to just use full time option and fuhgeddaboudit,
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Old Oct 30, 2011 | 08:08 AM
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caged: I agree with everything in your post but one point.

Off-road where one wheel can become light or off the ground, the 242 will send all the power to the wheel with the least amount of traction as it has an open diff in the transfer case.
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Old Oct 30, 2011 | 10:09 AM
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I broke an axle shaft and put the Jeep in 4Full Time for giggles and it would not move as all the power was being sent to the front left where I removed the axle shaft, meaning open differential in 4Full, but locked in 4Part.
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Old Oct 30, 2011 | 06:34 PM
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Originally Posted by AeroSynch
I broke an axle shaft and put the Jeep in 4Full Time for giggles and it would not move as all the power was being sent to the front left where I removed the axle shaft, meaning open differential in 4Full, but locked in 4Part.
My point exactly... Thanks.
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Old Oct 31, 2011 | 12:53 PM
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Originally Posted by cruiser54

Not BAD to use PT on the roads, but usually not necessary. It's what the guys with PT have to do.FT is smoother, doesn't bind, and can be left in all day forever if you want. Only your fuel mileage would suffer.

Off-road where there may be one wheel coming off the ground or getting real light, PT is better. Cruising dirt roads that are slick or real loose, FT works just fine.
Never ever ever ever use PT on flat hard roads. Per the manual, it should be used in times where there will be wheel slip. IE ice, rocky roads, steep inclines etc...
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