[FatAlbert]

I have a 1994 4.0L I6 with Selec-trac. Is this the 231? Do I have a VC?

I was just reading a post where someone said that a smaller wheel mixed into larger ones will ruin a VC unless you have a 231. So that confused me.


Thanks.


Here was the post:

Originally Posted by Jeepsunlimited forums

He does not have a VC... he has a 231 TC...

[phasewolf]

You have a np242 and that means that there is no viscous coupler.

[cmotsvt]

One thing I have always wondered about the 242 is what they ues to split the power front to rear in 4FT? Is it a differential?

[FatAlbert]

Originally Posted by phasewolf

You have a np242 and that means that there is no viscous coupler.

wow... that is nice to know, because that is an expensive fix.


Thanks.

[ArloGuthroJeep]

I believe fulltime uses an open differential but don't quote me on that...that is solely my guess and no knowledge behind that...4wd part time using a locked diff(center diff...) *shrug*.

The 231 is Command Trac...that TC doesn't have 4WD Full time, just part time. Its stronger then the 242 (Selec-trac) but doesn't have full time which is important for my DD needs during the winter.

-Ryan

[silvergc]

The 242 has a differential that is open for full-time and locked for part-time. Uses planetary gears.

[matt.x]

possibly one of the better TCs out there too. Gives you a little AWD and full locked 4WD too.

[walter_da_jpr]

Matt has got it right. It may not be extreme like Quadra-drive but the simplicity and variety are excellent, plus its reliable, unlike most quadra-drives.


Its an all around great value especially when you start wheeling.

WALTER

[FatAlbert]

Originally Posted by matt.x

possibly one of the better TCs out there too. Gives you a little AWD and full locked 4WD too.

Cool.

I'm a noob and last winter (I got this ZJ in Jan.), I always drove around in 4wd Part Time, as I thought this was the right choice for snow. I even used to use that for wheeling too... I use 4wd Low now for trail-riding. Which one do I use?

I see 2wd, 4wd Part time, Neutral, and 4wd Low.

Is this full locked 4wd you speak of 4wd Low or the 4wd Part time? Or neither?


As you can tell... I am one confused man.

[silvergc]

Sounds like you have a 231 (command-trac) transfer case. The Part-time and 4wd low are both settings with the front and rear driveshafts locked. There is no "open" setting on this particular transfer case. In other words, you don't have a 4wd setting that is appropriate for driving on surfaces with good traction (like dry pavement).

[Meerkat]

I think we are confused about what you have as well!

While you can normally go by the label on the bezel, the only way to know what you have for sure is to crawl underneath your Jeep (from the driver's side about even with the door) and take a look on the transfer case. There will be a round metal plate that will say NV231 (or NP231), or NV242 (or NP242).
If it says 231, you have Command-Trac, which (as has been pointed out), does not have a 4WD setting suitable for high traction surfaces.
If it says 242, you have Selec-Trac, which has an open differential, allowing 4WD full time use.
In any event, you do not want to use 4WD part time or 4WD Lo on surfaces that do not allow the wheels to slip.


HTH