Hello and thanks for tha add! I am from Germany Bavarian Forrest (So please excuse my poor englisch.) and have a 98 ZJ 5.2 since January.
This is my second Granny. Have a WJ 4.7 HO since 8 years.
The ZJ (better ZG) has a 3,5 " RE lift kit installed. i did a lot of work the last month. Rocksliders, Regearing 4.56. in the rear with the stronger JK gears.. Spartan locker rear, Detroit truetrac front, winch bumper...aso. Now i have a failed Viscous Coupler. Have read a lot of the 242 swap. i have now 3 options:
1. repair the VC,this was recommended to me too.
2. 242 swap from a 4.0 XK 1997 with ESY. I have bought a good one last week, because they are hard to find in germany. Question: the longer output shaft need a shorter driveshaft..
3.just now is a 242 in the neigbourhood availlable. I should be from a 95 ZJ, and has the ISY like my 249. the input shaft have to be changed before, because it is a 1990! .
It is a 242J, 5300 8081, 0 9 26 90 7. This one should be plug and play with my stock rear driveshaft.
What do you recommend me!
Thanks in advance! V/R Armin

because of the VC the car comes a second 249 from 94 as a spare part. I think the VC is dead too.
the 3.5 RE lift kit is without upper adjustable controll arms. only rear lower are adjustable.. because of the angle pinion-driveshaft.. this is the next problem.

 

I wouldn't spend any money at all on the NP249, they are junk, you can swap to an NP242 or NP231 out of an XJ or ZJ.

 

The only junk is the VC, isnt it?
And is the durability so bad?
If i repair it it should be fine the next years.
will only drive it offroad and for the trip to the offroad area 120miles round trip.
Summary 1500miles in the year.
(for longer overland trips i use my WJ 4.7HO.)

The chain should be stronger (1 1/4" 249 vs 1" 242)
And with the 249 i dont have to change my rear driveshaft, shift linkage...

 

The 249 it junk when it is working right, no way to lock it in 4wd high, and no 2wd option which makes you use more fuel.

 

ok, i have bought a 242 from a 1998 XJ 4.0. With ESY. it is 1.5" longer than the 249. with the jeep standing on the tires the rear DS has 30mm Yoke to sealing lip. complete lifted is is only 10mm. the DS is to long for the 242. is there no other way for fitting length than custom made? in the D44A i did a JK pinion and ring with fitting new yoke, because different splines. . maybe this is different length to the stock pinion.

 

Have a driveshaft shop shorten and balance your driveshaft.

 

Always so much hate for the 249.... 30k road miles and probably 40hours of trails(no rocks here) and I have had only one complaint.... Open diff 4wd burnouts are impossible! But 2wd behind a V8 and they never stop spinning. I swapped to a 242 recently, but the 249 is on the shelf.

 

The 2wd vs 4wd fuel economy debate means nothing if you don't have locking hubs on the front. Without locking hubs the full weight of the front axle turning assembly is applying load, even if it is off at the TC.

 

Driving the font axle uses more fuel than having it free spinning.

 

Soo.... We agree then?
My point was to not even consider 2wd vs 4wd economy unless you have the lockout hubs. And even then it's minimal.

 

No you just didn't understand, even without lockout hubs driving in 4wd uses more fuel than in 2wd.

 

Are you trolling me?

 

Hello and i´l be back

Will go back to this thread.

my transmission needs a rebuild or replacement because the 2. Gear is slipping.
i think a work for the autumn.
with this work i want to try the 242 swap.
my rear driveshaft has a length from 34,45" uu.
I cant find it in the chart.5,2 / 249 /int Slip yoke is in the chart only 31uu
As i told you with the jeep on the manstand and the wheels are free it is about 12 mm gap between the SY flange from the driveshaft and the ISY from the TC.
I have a second driveshaft, 33,25" uu, should be from the 4l 249 according to this chart.
I hope this 1,2" shorter driveshaft fits to the 242 esy .
what do you think about it?