Aaron Posted March 6, 2020 Share Posted March 6, 2020 I’m just starting to put together my MJ project (89 MJ 4.0 5 speed 2wd long bed) I have a 14b for the rear and a LP D60 in front out of a 77 f250 camper special. I originally planned on a ax15/NP231 for the 4x4 conversion but have recently been thinking about changing gears (gotta love a good pun) and exploring a Divorced tcase setup instead. Mainly because of the front driveshaft angle. I’ve tried finding some info pertaining to the subject but for whatever reason I’ve fallen short, which brings me here. So my ? is, am I barking up the wrong tree here or am I on the right track? A ford NP205 looks like a good candidate if I was to go this route but I want more info of what I’d be getting myself into before I commit to it. Let me know what you guys think. Link to comment Share on other sites More sharing options...
mnkyboy Posted March 6, 2020 Share Posted March 6, 2020 205 is a good case but limited on gearing. I would swap to a 4wd trans and run a crawl box into a second case, that will give you more ratio options and give you the driveshaft length/angle you are after. Link to comment Share on other sites More sharing options...
Smokeyyank Posted March 6, 2020 Share Posted March 6, 2020 What overall BW are your going to run? You going to stretch it? I wouldn't go divorced. You are going to sacrifice your rear DS angle for the front. NP205/203 doubler is a great set up but you'll need to stretch your WB to accommodate the longer driveline. Other options is as mnkboy said and get a underdrive box. http://www.northwestfab.com/NWF-BlackBox-Underdrive_c_7.html https://behemothdrivetrain.com/collections/strong-box-underdrives Link to comment Share on other sites More sharing options...
Aaron Posted March 6, 2020 Author Share Posted March 6, 2020 We tell you the truth the last thing I was worried about was the rear driveshaft length. Maybe it’s just my ignorance lol. Stock driveshaft is like 7’ long (maybe a slight exaggeration). I had also thought about a Dana 20 but it seems like an expensive option if I can’t find a Datsun Dana 20 that’s already divorced. The truck is 100% stock. I have the 4x4 ax15 mated to a NP231 but I wanted to get some more info before I installed it. I have plenty of time a patience and all I’ve done so far is pulled the Dana 35 and put a bastard leaf spring pack in the rear (Comanche mains with some Chevy 56” leaves mixed in). The 14b is going in this weekend! Link to comment Share on other sites More sharing options...
Aaron Posted March 6, 2020 Author Share Posted March 6, 2020 I wasn’t planning on doing any stretching of the WB I’m just trying to avoid a nasty front driveshaft angle and am exploring my options before I find out I need to the inconvenient way Link to comment Share on other sites More sharing options...
mnkyboy Posted March 6, 2020 Share Posted March 6, 2020 I run an AX15 with a crawl box and a built 231 with SYE in my short box MJ. I've pushed the front axle about 4" forward and the rear back about 1" giving me a 118" wheelbase. My driveshafts are 38-1/2" front and 40-3/8" rear, so even without the stretch they would both be plenty long enough to get a decent angle. My truck also has a tummy tuck which increases the angle, my drive shafts think I have around a 10" lift because of the tummy tuck. Link to comment Share on other sites More sharing options...
Aaron Posted March 6, 2020 Author Share Posted March 6, 2020 Humm...that def sounds like a good option for me. Looks like I have me some homework to do tonight! I would like to use what I already have instead of buying more parts (I’m sure my wife would like that too lol) and sense I already have the ax15 and NP231 might as well explore the option. And I guess I failed to mention I’m doing leaf springs up front so the WB might end up being stretched slightly by the time it’s said and done. What crawl box would you recommend and/or stay clear of. And what about gearing? Axles are 4.10 gears and I have a set of 38.5’s for tires Link to comment Share on other sites More sharing options...
mnkyboy Posted March 6, 2020 Share Posted March 6, 2020 You definitely want to watch the driveline angles with that set up, with that axle on leafs you will be fighting between driveline angle and caster unless you cut and turn the Cs, try to keep the lift as low as you can. NWF black box or their ECO box would be a good option, I run a Behemoth strong box on mine which is also good, but the company isn't as good to deal with as NWF is. Link to comment Share on other sites More sharing options...
Aaron Posted March 6, 2020 Author Share Posted March 6, 2020 I’ll def keep that in mind. I want to keep things as low as possible anyway so at least I have that working for me. I have some stock yj springs that are going up front and am going to emulate the yj suspension/steering up front. I got a crossmember I guess you’d call it with leaf spring perches on it (intended for Toyota’s being sas’d With 31.5 center pin to center pin) to weld on the front and match up to the d60. I have very limited fab skills so all my welding is going to be done by a pro. Link to comment Share on other sites More sharing options...
Aaron Posted March 6, 2020 Author Share Posted March 6, 2020 And I thought that way I could keep the angles generally as they where intended to be by doing it that way Link to comment Share on other sites More sharing options...
Smokeyyank Posted March 7, 2020 Share Posted March 7, 2020 Gears use www.grimmjeeper.com You can mess around with configurations to see what works well based on tcase and tranny set up. Guessing you're not planning on street driving so I'd go deep. 4.88+ Link to comment Share on other sites More sharing options...
Aaron Posted March 7, 2020 Author Share Posted March 7, 2020 Not really other than running it up and down the road real quick for a little test. I really am liking the dual case option! Seems like it will achieve what I’m after. Thanks guys!! I appreciate your input! Link to comment Share on other sites More sharing options...
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