JeepcoMJ Posted April 18, 2007 Share Posted April 18, 2007 like the title says. considering it as the next project as I've got some pretty interesting parts available...a late 70's j10 frame at the JY that is in fairly decent shape, with a dana 44 high pinion front end and amc 20 in the rear. idk what gears. engine-wise I believe I have access to a 6.5 diesel out of a chevy g-van, but am wondering on a tranny. the goal is leaf springs all round, a sturdy seperate frame, good off-road capability, and engine powerful enough for the truck to tow a decent sized trailer while getting fairly decent gas mileage. alot to ask for i know, but I believe that with the parts i may have available, it can be done. this would eliminate the unibody, and allow me to actually extend the cab with parts from a 2 door xj to make a club-cab truck with a 6 foot bed. COMPLETELY different animal i realize, but if you guys have any pointers on if it's worth the effort or not, if it can be done, what am I looking at for structural support.... i'm off work for 6 more weeks, and though i don't have money available, I believe that once i sell my sport truck this is a doable project...perhaps not in 6 weeks, but in a year, sure. input? jbhill i know you will have pointers on mounting to a frame... Link to comment Share on other sites More sharing options...
Oizarod115 Posted April 18, 2007 Share Posted April 18, 2007 if you check out jbs project thread, i think i got some shots of how he's building the frame to the body, don't remember how far along though, Jb is building a full custom floor too IIRC Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 18, 2007 Share Posted April 18, 2007 There's gonna be a few problems... A minute I need. Alrighty. J-10 frames are, from what I've heard, not exactly the best of items. I believe the are partially boxed and partially channel. Anyways, they have a tendency to flex like mad, and crack where they aren't boxed. Having the frame flex in this case will be an issue - the unibody itself is very stiff and the cab was never ment to see any major flexing (okay, I consider this debatable, I'm going by what the guys on NAXJA say but I never trust them). You can probably get around this by attaching the cab with rubber body mounts and running some fairly thick (3/16) flat bar along the floor following the profile of the frame, and boxing the entirety of the frame. I'd probably want 6 body mounts for just a MJ cab. 8 or 10 if you're to extend it. FWIW, the frame you're looking at unlikely has a HP axle. Unless it has been swapped from a F-truck. Which isn't likely either, J-10s only track 64" while a F-truck is 65-67" (not a huge difference, but it adds up as the rear only tracks 62"). And the f-trucks were either 5 or 8 lug, so the outers would have to be swapped. If I was to do it, which I have mused about and still am... I would build my own frame using 2x4x.125 HSS and use just a few more cross-members that any factory vehicle... Read that as a full belly skid made from a honeycomb structure and UMHF (or whatever that plastic is). And tie-in a lot of tube. Just because that suits me more than doing it any other way and I am somewhat afraid that the what I've head regarding flexing being an issue may be true. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted April 18, 2007 Author Share Posted April 18, 2007 that's my plans on custom floor...i would like to remove the comanche frame rails. put some bars across the bottom of the cab to support it on, and I'd like to actually bolt the body to the frame... worked on the body styling a bit... Link to comment Share on other sites More sharing options...
Oizarod115 Posted April 18, 2007 Share Posted April 18, 2007 fixed rear doors i assume? looks tight, you thinkin buckets or fold down bench in the front? seems to me you'd have to brace it as you cut the floor out, other wise the body may flex and you'd have a b*@$£ of a time gettin doors and glass aligned again? :nuts: right? Link to comment Share on other sites More sharing options...
JeepcoMJ Posted April 18, 2007 Author Share Posted April 18, 2007 thanks...i hadn't thought of bracing. but you're correct. it would be buckets in the front with a full center console (and probably less of a drive hump), and either a comanche folding bench in the rear, cherokee 2dr rear seat, or another set of buckets with a folding center console that doubles as a middle seat. and yup, just front doors. I like the longer doors off the 2 door cherokee though. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 18, 2007 Share Posted April 18, 2007 See my edit. If nothing else I want to see how this goes to borrow ideas. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted April 18, 2007 Author Share Posted April 18, 2007 more ideas... Dirty, i was thinking along the lines of you with boxing in the frame. I haven't got the option of my own frame, especially since that would defeat the purpose of easily upgrading to a solid frame with limited time spent with axles and springs. I really just want to see if I can do this. as of now, my decision is that I need a 2 door cherokee that's either hit in the rear or has a blown motor...easier to start the swap there and end it with a comanche back half. so, I would box the j10 frame (or wait on this project but continue with design until i find an m715 frame), and add many extra crossmembers. I have the interior planned out...all 4 seats will be power, with all 4 being cherokee buckets and the fronts being able to tip forward. tip-down middle seat for the rear will serve as a armrest. floors will be completely custom with the exception that I will keep the drivetrain hump intact. I will more than likely add some room by making the floor a little lower and removing the incline the floor has to make it a level surface. custom seat brackets will then be needed as well... I don't think i'm worried about body flex. if I mount it as you suggest, and reinforce the frame as you suggest, it should be a good project. I think the way to go is going to be to get the frame, mount the engine, and find a transmission that is suitable to the project. or at least mock up the engine position and figure it relative to the firewall of the comanche and desired height off the frame I wish the cab to be (which will be around 1/2 inch). the bed will have to be a shortbed, a custom stepside, or a bobbed (on both ends) longbed box. this thing will get a gooseneck if I design it with a powerful enough drivetrain as compared to a fullsize. my grandpa owns a construction company and a few trailers i could possibly borrow from time to time. do you think this could be done if the flex situation can be addressed? and would you think it would be a good towing rig when complete? oh, another reason i want an existing frame is for available lift kits. I don't wish to have to piece things together... Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 18, 2007 Share Posted April 18, 2007 I say give it a shot.... One thing to consider is building a cage for it now. Regardless of how you wheel, rollovers happen off-road and on. With the thing already ripped apart it'll be very easy to add one and make it work with how you want to use the truck. Also, if you tie it in far enough frontwards and back - it'll greatly stiffen up that frame and get a couple birds stoned at once. Do you want an auto tranny or a stick? For an auto I'd recommend a TH-400 behind the 6.5. They came stock, making it easy, and can be bolted to many different tcases. For a stick, if you can live with only 4 gears, I'd go sm420 or sm465. Cheap and indestructable, with a great granny gear. Again, you can bolt them to a lot of different tcases. For a 5spd there's not many good options - most won't bolt up easily or will be very expensive. You'll want to decided on a tcase too. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted April 18, 2007 Author Share Posted April 18, 2007 well for economy purposes I would like a manual...but a 4 speed is out. for useability and ease in driving, plus off-road-ability, I suppose i will go auto. a TH400 is what I will do. for t-case I'm not sure what's available. i don't want fulltime so i obviously don't want AWD. what should I do for a tcase? and you're probably right about the roll cage. but it needs to allow easy access to the rear, and for my own purposes, easy removal of interior pieces. as far as I'm concerned, that makes it not within my standards...and I don't want an exo either. although...i suppose if I put the cage in with no interior panels, and got it as tight as i could to the body, I could perhaps construct my own interior panels or even simply carpet the cage to look nicer... whew, i'm lookin at a hefty project here...but this would be killer if I can make the parts happen. Dirty, what do I need wiring-wise for the 6.5 and the th400? I don't know if the 6.5 is electronically controlled or not... or does anyone have a better suggestion for a motor? the 6.5 would be ideal for me but I AM open to suggestions on this. it's currently a dream, but hoping for reality... Link to comment Share on other sites More sharing options...
feerocknok Posted April 18, 2007 Share Posted April 18, 2007 F' the Comanche's tranny hump! I hate that thing! This sounds like alot of work! I don't imagine any particular problems with the whole thing, but (like I always have) I wonder about the gauges. And I hope you have a good cutting tool! Link to comment Share on other sites More sharing options...
JOMJ87 Posted April 18, 2007 Share Posted April 18, 2007 For what i matters i forsee the rear axle as being something that needs upgrded I am thinking its got 2 piece shafts unliek the MJ one. I was just thinking i would mention it if it hasnt been brought up before. Cole Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 18, 2007 Share Posted April 18, 2007 I think you can get the roll cage under the body panels, or at least mostly under them - so it sticks out about 1" at most. I mean, you can get away with 1.5" tubing (or uh, pipe...) for an interior cage easily enough, and there's a big whack of space under the interior panels in most places. It'll take some creativity, but I think if you're already doing a major hackjob you can get it to fit. Dirty, what do I need wiring-wise for the 6.5 and the th400? I don't know if the 6.5 is electronically controlled or not... or does anyone have a better suggestion for a motor? the 6.5 would be ideal for me but I AM open to suggestions on this. it's currently a dream, but hoping for reality... Ever driven a 6.5? They're pretty slow. Very reliable though. And lighter than the cummins. Personally I think if you're bent on a diesel it's a decent choice. But, that's at least what my friends tell me, I'm not a diesel guy. Although, the cummins 4BT would be a good choice if you can find one - they're all mechanical. The 6.5 has a harness and computer. What it does I don't know. Like I said, I'm not a diesel guy. The good news is the TH-400s don't use any fancy computer gizmos - I think they only need a throttle position cable. Again, I'm no expert on them - they have several different incarnations because they were used for so many years. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 18, 2007 Share Posted April 18, 2007 For what i matters i forsee the rear axle as being something that needs upgrded I am thinking its got 2 piece shafts unliek the MJ one. I was just thinking i would mention it if it hasnt been brought up before. Cole No, it's got 1-peice shafts. But, a truss would be a very good idea - they used rather thin/small tubes that like to bend. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted April 18, 2007 Author Share Posted April 18, 2007 F' the Comanche's tranny hump! I hate that thing! This sounds like alot of work! I don't imagine any particular problems with the whole thing, but (like I always have) I wonder about the gauges. And I hope you have a good cutting tool! plasma cutter all the way. and I'm gonna have to make some control boxes/signal converters for the gauges...i don't think it's gonna be a simple swap sending units and go. and the tach. will not be working off a simple 3 pulse AC signal either...so i will need to convert that as well. it can be done. and i guarantee with something like this...i'm gonna want full gauges. lol, perhaps an OEM xj/mj diesel gauge cluster with turbo? then i could turbo the engine as well :P if I do this project....it's gonna take not so much time to finish the frame and axles, and perhaps not too much to get the engine and tranny mounted. but the body...will be another story. I can cut, measure, weld, and grind well enough, but the finishing touches on the exterior will be my biggest issue. that and if I have to do any plastic welding...that'll be an experience. but imagine yourself in a powerful, capable diesel comanche, with 4 adult size seats with full power, a sleak, redesigned dash (maybe a 97 to 01 while i'm dreaming), air conditioning, and a nice gooseneck trailer behind you on the way to moab with yours and your buddies wheeling trucks on back.... hahaha, keep dreaming...maybe THAT will happen when they produce the gladiator... this is a project i'm going to think through, and design first. i need blueprints to make this work...because I would like to retain as much structural integrity as possible. I'd probably use this as a DD but wheel it too. the 3800 is basically a street only truck...so this would be my toy Link to comment Share on other sites More sharing options...
JOMJ87 Posted April 18, 2007 Share Posted April 18, 2007 Damn i could have gotten a J10 setup for the MJ awhile back for 50 bucks and thought i didnt want to mess with it. it even had 4.10s or something close. That was when i thought of going fullwidth. Thansk for the info i just wanted to make sure it wasnt overlooked if i was right. Cole Link to comment Share on other sites More sharing options...
JeepcoMJ Posted April 18, 2007 Author Share Posted April 18, 2007 For what i matters i forsee the rear axle as being something that needs upgrded I am thinking its got 2 piece shafts unliek the MJ one. I was just thinking i would mention it if it hasnt been brought up before. Cole I don't think I'd do anything spectacular with the axles to start out with...I really should hold out for an m715 frame, cause the goal in mind is gonna be dana 60's front and rear. I think you can get the roll cage under the body panels, or at least mostly under them - so it sticks out about 1" at most. I mean, you can get away with 1.5" tubing (or uh, pipe...) for an interior cage easily enough, and there's a big whack of space under the interior panels in most places. It'll take some creativity, but I think if you're already doing a major hackjob you can get it to fit. alright that makes the interior rollcage OK. it would add some interest to the vehicle, and peace of mind as well. if I can hide even just half of it...then it's good. Ever driven a 6.5? They're pretty slow. Very reliable though. And lighter than the cummins. Personally I think if you're bent on a diesel it's a decent choice. But, that's at least what my friends tell me, I'm not a diesel guy. Although, the cummins 4BT would be a good choice if you can find one - they're all mechanical. The 6.5 has a harness and computer. What it does I don't know. Like I said, I'm not a diesel guy. The good news is the TH-400s don't use any fancy computer gizmos - I think they only need a throttle position cable. Again, I'm no expert on them - they have several different incarnations because they were used for so many years. yep, i drove the g-van that the engine is in now. the van was rolled 6 times and it still runs and drives with no problems other than the rear axle grinds and whirs and it's got a bend in the frame. but it's not too shabby on speed actually...they'll do 90 no problem with a fully loaded 10,000 lb. tool trailer. I think i'm bent on the 6.5 for the simple fact that it's available to me and seems like it will work fine. Link to comment Share on other sites More sharing options...
CEThomas Posted April 18, 2007 Share Posted April 18, 2007 Well I can help on this topic :D First if you can get your hands on a 6.2 you will be better off as the 6.5 has a ele. injector pump and the 6.2 has a mechanical pump. Then if you get a 6.2 get a Banks turbo system, 4" ext. system, and turn the pump up 3/4 turn. The fuel milage will go from 22mpg to 11mpg but she will pull and be quick off the line 8) As trans go you do not have much of a choice behind the 6.2 / 6.5. The 4L80E is the only auto the will bolt up to the 6.2/6.5 and take the tork. And they are hard to find and go for high$$$. The 5sp NV4500 that GM put in it was crap but you can get a trans out of a 90's Dodge Ram with a Cummins and I can hook you up with a place that has a kit to fit it up to the 6.2/6.5. Charles Link to comment Share on other sites More sharing options...
500 MJ Posted April 18, 2007 Share Posted April 18, 2007 Go for it Patrick, just make sure you have the funding, tools and space to see it through... My Dad doesnt like it when I take up his garage space for extended periods of time :mad: Link to comment Share on other sites More sharing options...
CEThomas Posted April 18, 2007 Share Posted April 18, 2007 yep, i drove the g-van that the engine is in now. the van was rolled 6 times and it still runs and drives with no problems other than the rear axle grinds and whirs and it's got a bend in the frame. but it's not too shabby on speed actually...they'll do 90 no problem with a fully loaded 10,000 lb. tool trailer. I think i'm bent on the 6.5 for the simple fact that it's available to me and seems like it will work fine. If it has a 6.5 with auto go with it. Switch out the turbo for a banks and if you can find a doner 6.2 dump the 6.5 injector pump and put the 6.2 pump on. Get a free flow ext. on it and a K&N filter so she can breath. I had a 2500 up to this x-mass when I blew the engine. Now I have my eye out for a k-5 that I can drop a 6.2 in. Charles Charles Link to comment Share on other sites More sharing options...
Rokhound Posted April 18, 2007 Share Posted April 18, 2007 There was some thing over on Pirate about this of course the guy was flamed and not supported (that is why I like this site) we all support each other even if it sound out of the this world (not say that these is) but it is out there. Any who get down of my box now I think that it would work your going to have to get with jbhill and exchange ideal on how he body drop his. And one thing I think you are going to want to do is build an exo around the truck and tie it in frame (MJ frame that you make) into the frame of the donor truck. One thing that would be worried about is how much the “new” body flexes in relationship to the new frame. I think if you take some measurement of the MJ frame that the donor truck frame you might be able to slide the frame rails down between the frame rails of the donor truck keep the main body strong and just tie it into the donor truck frame Looks like a lot of work and I have kicked the ideal around to but I just don’t think that it is worth the money/time. But then again am not flame on for think out side the box. Good luck and can't wait to see this thing going. :popcorn: :popcorn: :popcorn: Link to comment Share on other sites More sharing options...
mudrunt Posted April 18, 2007 Share Posted April 18, 2007 in regards to the tranny, a 700R4 will hold up to a 6.2/6.5 a buddy of mine has one behind his 6.2. As far as the 4L80E lots of money for the tranny alone not to mention a controller for it. They run anywhere from 500 to 1500 dollars. Sounds like a good idea I personally would go cummins reliability and brute strength can't be beat. My opinion though I work for Cummins so I am biased. Link to comment Share on other sites More sharing options...
CEThomas Posted April 18, 2007 Share Posted April 18, 2007 A 700R4 will work, but it's not great for heavy pulling so I wonder if it would not be a great choice for heavy off road. Cummins is they way to go :cheers: If I kept the GMC I would have put a Cummins in it when I replaced the engine:D It took a lot of work and $$$ to get the 6.2 pull like a out of the box Cummins, and never could get it to sound like one :cry: Just wish I could get a little Cummins for the MJ and my Ranger :D Charles Link to comment Share on other sites More sharing options...
mudrunt Posted April 18, 2007 Share Posted April 18, 2007 my buddy uses his to pull an 18' car trailer and his full size 4x4 chevy back and forth when we go wheeling which is and hour away. Your right they are slow as a turtle but he gets there just the same as my cummins does. A 4bt can be found check with your local agriculture scrap yards or farm auctions that have Case skid steers listed. They all have 4B and the new xt75 should be turbo charged if i remember correctly. throw a nv4500 behind it and have all kinds of fun. Link to comment Share on other sites More sharing options...
CEThomas Posted April 18, 2007 Share Posted April 18, 2007 Slow is right, I used to pull a trailer and my tractor ( about 12,000#) to and from Amanda, OH to our place in Tellico TN all the time. After the first trip my Truck pull buds helped me get things fixed so I could make the trip in 7hrs over 13hrs :headpop: Charles Link to comment Share on other sites More sharing options...
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