Building a ZJ
- Thread starter Gs_Jeep
- Start date
The 249 is stronger, and there is no great reason (unless the 249 is dead, you want 1-2 extra miles per gallon, or you want 4:1 gears) to swap in a 231.
That being said, 231 swaps aren't very difficult. Most late model 4.0 Tj's/XJ's with auto trannies should have the correct input shaft length/spline count to swap into the v8 ZJ's. Getting the VIC (the little thing that tells you that you are in 4lo etc.) to work takes a little more effort but I think there are some people who have figured that out--I never cared enough to mess with it.
If the 249 goes out, it's deffinately less expensive to do a 231 swap, otherwise the 249 that you have is a good case. In 96 it got a locking center diff, which is the reason the pre 96 249's suck balls and the reason most people get rid of that case in favor of a 231/242
Cody
That being said, 231 swaps aren't very difficult. Most late model 4.0 Tj's/XJ's with auto trannies should have the correct input shaft length/spline count to swap into the v8 ZJ's. Getting the VIC (the little thing that tells you that you are in 4lo etc.) to work takes a little more effort but I think there are some people who have figured that out--I never cared enough to mess with it.
If the 249 goes out, it's deffinately less expensive to do a 231 swap, otherwise the 249 that you have is a good case. In 96 it got a locking center diff, which is the reason the pre 96 249's suck balls and the reason most people get rid of that case in favor of a 231/242
Cody
crimsonride
huh?
- Location
- Murray
I changed over the 249 in my brothers 5.9. It's not hard at all to do but like Cody said, no point unless it's dead.
I'm trying to remember what we did with the VIC, I think we just used one from a 231. We did a sye at the same time.
I'm trying to remember what we did with the VIC, I think we just used one from a 231. We did a sye at the same time.
95jeepgrndchke
Senior Member
- Location
- In the ZJ
Mine wasnt to bad when i did mine. I had a NP247, crummy all-time 4 wheel one and she blew. I agree with Crimson and Cody dont do it until you blow the other one up. But as far as the VIC goes, I know when im in 4 low 
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95jeepgrndchke said:Mine wasnt to bad when i did mine. I had a NP247, crummy all-time 4 wheel one and she blew. I agree with Crimson and Cody dont do it until you blow the other one up. But as far as the VIC goes, I know when im in 4 low
247's came in WJ's with Quadradrive or quadratrac or whatever that is.
the 93-95 AWD 249's suck cause they lack a locking center diff and you can't run them w/o a front driveshaft w/o burning up the VC. The 96+ 249's have a locking center diff, a 5/95 torque split (so reasonable close to 2wd), and you can run them w/o a front shaft w/o problems. the 96 and newers aren't bad cases--no need to swap unless you blow something up IMO.
Cody
95jeepgrndchke
Senior Member
- Location
- In the ZJ
Ok maybe it was a NP249 I havent talked about that case in a long time, kinda just threw a number out there.
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95GC: I know you know your ****. I'm just messin with ya
G's:
What I'm/we're saying is the 'center' diff is locked. the pre 96 249's didn't have a locking center diff so the torque could/would split unevenly to the tires that spin easiest--front to rear. That sucks (just as open axle diffs suck), so the 96+ 249's got a locking center diff and a completely different torque split front and rear in high range than the older 249's.
G's:
What I'm/we're saying is the 'center' diff is locked. the pre 96 249's didn't have a locking center diff so the torque could/would split unevenly to the tires that spin easiest--front to rear. That sucks (just as open axle diffs suck), so the 96+ 249's got a locking center diff and a completely different torque split front and rear in high range than the older 249's.
crimsonride said:
We didn't do anything with the VIC. The swap wasn't hard except for oversights on our part, which required us to remove the TC twice to correct. At this point, either of us could do it with our eyes closed in record time.
95jeepgrndchke
Senior Member
- Location
- In the ZJ
It is the NP 242, The viscoius coupler will wear out, i had mine do it to me about 3/4 up on Dump Bump, then front tire(s) wouldn't even spinutahxjer said:
. And I know also that the Low Range in that t case isnt very low, plus it doesnt send equal power to both ends of the drivetrain, so it isnt very low-low range. I noticed a world of difference when i put my NP231 in, you can get a good deal on one if you be patient enough. Mine was out of a 2001 TJ and i got it fir $150
- Location
- Bountiful, land of rocks
utahxjer said:
From what Cody said above, this is kinda the 'undesireable' year of the 249?
95jeepgrndchke said:It is the NP 242, The viscoius coupler will wear out, i had mine do it to me about 3/4 up on Dump Bump, then front tire(s) wouldn't even spin
I have/had a 242 in my ZJ/XJ and honestly, they are the same gear ratio as the 231 (they do have the viscous coupler for 4WD high-"Full Time" but also have the 4WD high-"Part Time" which 'hurks' when on a tractable surface like a 231). I think the 249 that came with the V8's might have a different ratio, but I don't know. The 242 was a pretty decent case, IMHO. Are you sure you had the 242 and not the 249?
I'm not any kind of a ZJ/WJ authority or anything, from what I've seen the V8's pretty much came with 249's and CV joints in the axles (I'm sure not ALL of them) and with the 6 cyl, you get the 242 with 297 joints in the axles.........
95jeepgrndchke
Senior Member
- Location
- In the ZJ
Yeay i meant the 249 sorry T-case info Check that site out it talks about the lo-lock issue
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95jeepgrndchke
Senior Member
- Location
- In the ZJ
Just as long as the boots arent busted open, Mine have held up fine on some good beatings. The only time i had an issure is when one busted open and got mud in it then blew up, I picked up some re-mans from auto zone for $79.99 a side and they are lifetime warranty.utahxjer said: