I just bought a jeep cherokee, but it did not come with a manual. Can someone send me a link to a thread or explain to me the do and don't of using it (IE can I use it on the highway when it is snowing).

Thanks again,
-Lex

 

You can when it is snowing yes but only in four high.

 

When traction conditions deteriorate to the point you have slippage. But if you have a 242 t/c you can run in fulltime 4WD anytime you like, in any traction conditions.

 

Not to steal you thread but every time I put mine into 4x4H, a part time light comes on the dash. I even tried it in low and the part time light was on. Once I take it out of gear the light turns off. Now my dash looks like they cut all the corners...two gauges speed and gas. Maybe the 4x4 light also took the back seat

 

you probably have a 231 TC you have no full time gear

 

You would have the other TC the NP231.

PART TIME light is the only thing that will light.

Do like Blue said... use it only when traction conditions deteriorate and slippage occurs.

BTW: You didn't steal the thread... you kinda borrowed it for a bit.

 

When I am driving (slow speed) and I put it into 4H, the Part-time light turns on. I tdoes this mean? How do I know it is a 242 transfer case?

Thanks,
-Lex

 

if you have a part time and full time 4H it is a 242. if it is all part time then it is a 231

 

Did a little searching, looks like I have the NP231 instead of the NP242. What does that mean? Which is better?
Thanks

Lex

 

Well, you should almost never use part time 4x4 onroad unless you have deep snow. the 242 i think is better because the fulltime mode is great for onroad use. in full time 4x4 the front tires differentiate in speed, but in parttime they dont(leading to slippage or on dry roads the tires will chirp/bark)

 

the main difference between the np242 and np231 is that the np242 has it's own "differential" that allows the transfercase not to bind between front and rear axles.

the np231, however, locks the axles to each other. so, there is no slip between the two, and it can bind up and detonate at road speeds on dry/decent traction conditions. the reason it would detonate is because the front axle also gives you the ability to turn...when you turn, this creates a different travelling speed of the front differential vs. the rear differential, which causes the front input on the transfercase to attempt to move either slower, or faster. this, of course, isn't going to work since the 231 literally locks the front and rear shafts together.
another reason it could bind is the minor difference in rear vs. front gears...i.e. my rear dana 44 has 4.09 gears, the front has 4.11 gears. they're close, and what is available. however, "close" is only good enough in situations with at least a small amount of slip to allow for differentiation to accomodate the minimal difference in differential rotational speeds.

the np242 in full time acts as an open carrier would...it's not locked front to rear. the ONLY downside to this is more moving parts. more moving parts is almost always a quicker way to failure.

that said, there's nothing wrong with your np242. just don't drive it in 4wd on the highway...a friend of mine did that, and ended up with a driveshaft coming through the floor just missing his leg.

 

if you have a 231 and you drive in 4x4 on the road a lot, its gonna spit teeth after a while. thats what jeepcomj was actually saying. lol

 

on a similar note, is there a 'proper method' to switching into 4WD?
the previous owner of my xj told me that it's best to switch to part time/full time while in neutral and rolling and into 4Lo while stopped and in neutral

is this correct?

 

You can shift into 4-hi at any speeds up to 55 mph (according to my old manual). It doesn't have to be in neutral.

For 4-low, it's best to shift when it's coasting 2-3 mph and in neutral. I find this the easiest way to get it in gear. You can do it when stopped but you risk grinding the gears and they sometimes do not mesh properly.

 

I have always tapped mine into four high at any speed and just put it in neutral to be on the safe side. But I always stop to go into four low. If I need it in low range I,m gonna be crawlen anyway.