NP231 Beef Up after SYE Question

99 XJ with 231J. I want to swap in the gears/chain from a Chevy Blazer 231 (chain is wider) as well as replace my 3 planetary set with the 6 planetary set from the same tcase.

Question/Issue
I installed a SYE kit 3 years ago (forgot brand name) and am wondering if the HD short shaft in that kit will be compatible with these parts?

They should be fine, just make sure you get the closest match of the planetaries to your t-case as possible. Around 96 they changed the gear pitch so if you get too early, or too late you may hear a gear whine from the case. What year is the 231-C donor? As long as you didn't have to use a different main gear on the new mainshaft, then you should be fine using the 231C parts on it, the most you may have to do is press out the old bearing in the donor main gear assuming it is even there still...

I built a T-case the same way for my XJ build, planetaries, chain and sprockets and an AA SYE. Still working on the Jeep so haven't used it yet, but soon lol.

Best of luck with it all!

Paint

Check out my Vortec thread in the Street & Performance forum. I covered this as part of build.

I've never seen a chain break. Ton's of people have wheeled hardcore with the 231 and stock chain. The biggest thing you can do is install a 2low kit so you don't have to run 4wd on hard surfaces, like wheeling in Moab on slickrock. The chains can stretch eventually with lot's of use on hard surfaces, but it takes awhile.

Of course, nothing wrong with bigger parts, but you probably don't need them.

Don't know the year of the 231C. Haven't even taken it apart yet...

Only thought about it cause I got the 231C for free and did some research before I scrapped it... Figured it might not hurt to add bigger parts. I am also working on a stroker project which is why I wanted the added strength...

you still dont need it. plenty of guys on 231s with SYEs with strokers, 350s, and 5.3s with big tires wheeling without tcase issues.

I used a newer 231c with the electric shift, The chain was the same size as my 2000 231j chain and the planetarywas the same as well. If i were to search for a case for the purpose to beef those up it would be a 241c. Or you can get those parts from JB conversions as well.
As for the sye it should work just fine..