NP242 vs. 231, and one really dumb question...

What's the real difference between a 242 and 231 t-case?
I understand that the 242 has one more selection for 4wd, why is this? Does anyone know how it functions? My reason for asking is because my 88 woody has a 242, but it's been giving me some trouble as of late. When I shift it into 4 full-time, the dash only reads part-time. I'll turn a corner and I can feel the wheels binding up. after a few hundred yards, it will finally go into full-time. And getting it out of 4wd is a trick in itself.
I have a question that is so dumb, I'm embarresd to ask.....
What is the correct way to engage and disengage the transfer case?

Also, could I swap in a 231?

Sean

first thing I would check fluid level (Mercon/dextron) and linkage. the difference is that the 242 has the full time feature witch allows the transfer cased to slip between the front and rear (like when on pavement) to give better traction and prevent breakage for that I prefer the 242 (makes it nice to drive in the snow) but everyone sayse the 231 is stronger. you can easly interchange them as long as you use the proper linkage. the 231 uses vacume to disconect the axle but if you go from242 to 231 just dont bother runing vacume lines the the TC

The correct procedure is to stop shift to neurtal and then shift into four wheel drive. If it gets wedged in four wheel drive....back up a couple of feet and then try it again. You can't drive a 231 in four wheel drive on dry pavement like you can with a 242, but I hate that anyway so I like the 231, on my last Wrangler the only thing that never blew up or gernaded was the 231 case. Just my $.02

the owners manual for the 242 says you can shift between 2wd and full time any time you are at or below 45 mph to shift into 4low you need to stop and shift into neutral as stated above.

"What is the correct way to engage and disengage the transfer case?"

Drop it into 4 full-time while moving at a moderate low speed and do this at neutral throttle .... if the light says 4 part-time then it locked on you ... just keep driving straight and throttle the motor a bit ... back and forth ... until it unlocks and the 4 full-time light should come on.

To disengage ... do the opposite, again, at neutral throttle and if it locks-up before you get it in 2WD ... throttle it the same as you did before.

Sometimes they get stubborn ...

You can shift from 2WD into either full-time 4WD or HIGH RANGE part-time 4WD while driving at moderate speeds. The manual says up to 45 MPH, I've done it going somewhat faster. The key, as someone already noted, is to shift when you are at neutral throttle (neither accelerating nor decelerating). To go into low range (which is part-time only) you should be stopped, or just barely rolling.

If your transfer case is getting hung up in part-time when you want to be in full-time, first change the fluid (uses ATF, the same stuff you use in the automatic), lubricate the linkage (you'll have to crawl under the driver's side of the vehicle with a squirt can of oil), then drive it slowly down a straight road and shift in and out several times. If that doesn't fix it, the linkage may need to be adjusted.

I would have to "goose" it a little to get it into and out of 4wd high. Has to do with engine vacuum. It definitely shifts differently than the 231. I loved mine. Great for slick/rain/snow/sleet conditions.

Also check your tire pressures. They all must be the same, at least side to side. A couple pounds difference WILL cause it to delay the engagement/dis-engagement.