NV242 swap into NV231 XJ

Hello folks-

long time FSJ owner (Wag/Chero/J Truck), just got the XJ religion.

I just bought a 91 Laredo for my wife, and I'd like to swap in a 242 in place of the 231. I assume the 242 will bolt to the AW4, and that I might need new driveshafts, but what about cosmetic stuff like the console and shifter issues?

I plan to grab a yard 242, and rebuild it. Is there a good source for a complete rebuild kit, and are the diffs rebuildable/do they typically go bad?

If you guys have a link to such a swap, that would be great!

Thanks

XJ_CONVERT

I have never done this swap, but I have taken a few out. The maindifferences I observed was the linkage, and shifter gate. There also might be a different spline count on the input shaft. I forgot what yrs they switched, but there are 2 different spline counts. you will also ned to get the shifter gate for the console. The driveshafts are about the same if I remember correctly.



Good Luck
Patrick

I know this has been covered before but I just completed it and wanted to post pictures in case it might help someone out.
I picked up a used 231 out of a 2003 TJ with 18000 miles. The ZJ I have is a 1994 4.0 and using the 249. I also am running the Ford 8.8 rear diff with disk brakes. I have a 6” lift so I wanted to use an Advanced Adapters SYE kit for a couple of reasons. Not just for the drive line angles but I also did not want a slip yoke that sucks dirt in the seal all the time and causes it to leak. The SYE kit solves that problem because it has a flange and is also over 4” shorter with the kit installed. When I picked up this ZJ it had a mix of Tera, RE, and JKS control arms. I really wanted to move to all RE stuff along with the Mono Tube shocks. I have used this setup on other jeeps and it works great. The Tera and the JKS bushings were shot so it was a great time for an upgrade anyway. I went down to All J Products in Colton CA and they had everything I needed to get this job done. They also use the J.E. Reel driveshaft. And Quinn was able to find the 231 tcase for me. We pulled the 249 tcase out and by chance it had the same length input shaft on both the 231 and the 249. Those shafts have to be the same. The 249 input shaft will fit in the 231 case but you have to be sure of the right gear cut and also the spline count on the input shaft. There seems to be an older 21 count spline and the newer 23. The 249 and 231 I had both had the 23 spline count. Also the shift lever is different from both of these cases. You have to use the right one…Be sure to use the lever that came with the tcase. The short one if the 231 and the longer one is the 249. You can not use the longer lever from the 249 on the 231… it will fit but will not allow the 231 to shift right. Pulled the 249 out…installed the SYE kit in the 231…installed the 231 in the ZJ. Measured for the new drive shaft and called it in . Had it the same day and installed it. Filled the case, ordered the new shift pattern plate from the dealer and everything worked great. Set the new pinion angle in the rear and took it for a test drive…no vibes at all. I know this has been covered a few times but just wanted to give an update on the swap. Was a very easy swap to do and had no problem at all. Later...Clint

















This might help also. http://www.naxja.org/forum/showthread.php?t=47991 There are 2 spline counts 21 and 23. There are also 3 input shaft lengths. Med length is rare. The swap has to be the same length input shaft. Use the lever that came with the t-case you are going to use...do not swap them. The gate...is really just in the t-case. not a plate in the shifter or anything like that. You should be able to use the same shifter...but you will have to order the shifter pattern plate (plate besides the shifter that lights up at night) from the dealer or someother place that has them. Hope this helps. Later...Clint

Thanks, can you give me a year on when the 21 to 23 spline changed?

Thanks

XJ_CONVERT

xj_convert said:

Thanks, can you give me a year on when the 21 to 23 spline changed?

Thanks

XJ_CONVERT

Click to expand...

I think it was 1991 and earlier were 21 spline. IF YOU READ ENOUGH on 242 swaps its in there somewhere thats where i found it. I have it bookmarkers somewhere if you can't find it. PM me after you read up if you can't find it. Search on rigid steel for rebuild kits.

I have been reading up on the swap, and I see conflicting info on the year that it changed. Just looking for a consensus before I start pulling cases.

Appreciate the time!

Thanks

XJ_CONVERT