....ok, maybe none of that applies, in reality, i just got in a new main shaft for my np242, and a new tail housing.....well new to me, but both used off ebay ($35 & $20)

 

What are the differences between the 231 and 242, rebuilt my 231 but have never worked on a 242

 

the 242 has full-time 4wd, which is essentially a differential between the front and rear output. the cases look nearly identical though.

 

So the front shaft could spin alone from the rear shaft, and at different rates? (In full time)

 

correct. i don't know if there some sort of a limited slip mechanism in it, but if you take the rear shaft off, and put it in full-time, you barely move (if at all, i don't remember), while in part time you will move since the front & rear shaft are locked to spin the same rate.

 

Wow so much better in bad road conditions, thinks for schooling me ha ha

 

When in Full Time the center differential is open, allowing power to be sent to which ever wheel has the least traction. This is incredibly useful for taking turns on pavement as there is no "hop" or lurching from trying to make the front wheels move at the same rate as rear. Part Time ( same as 4 Hi), the center differential is locked in place forcing 50% of power to the front axle and 50% to the rear. Now, if a locker were involved then the power would be split 25% to each... And some strange 2/3 split with a limited slip.

Edit: accidentally hit send on the iphone app...

 

definitely good in wet weather for better take offs, lol, was a short lesson

 

yep, right on the nail

 

so here's what i got done yesterday, took the old shaft out, got the new one in.

 

I'm sure ill learn more from time to time

 

lol, i just learned something today! found out that the shaft changed from the older np242 to the newer np242 (internal slip yoke to external slip yoke). so now i have to wait for the old style housing to come in from ebay ($30) before i can fix my t-case! looks like i will try to mess with the linkage today to see what i can do about the 231 popping out of 4wd

 

Look great! Thats a nice xj. And I like all the neon green on everything it really looks awesome!

 

That's all you can do really.

 

thanks man, it all started with lime green shock boots, and grew from there, lol