fiscus Posted March 20, 2007 Share Posted March 20, 2007 Ok, I have a lot of experience lifting XJs, but I might be a little confused as to MJs. My MJ is currently 2wd & I am thinking of making it 4wd; I would like to go ahead & lift it at the same time if possible. I think I could use F150 coils & spacers for the front (like on an XJ), but what would be my cheapest option for the rear? I know it's sprung under, so adding lots of leafs is not the answer... (I would like to keep it around 4" total lift, so I assume a simple SOA is out of the question?) Link to comment Share on other sites More sharing options...
Duner Posted March 20, 2007 Share Posted March 20, 2007 Are the f-150's coils the same diameter as the XJ/MJ? what about overall height versus installed height? and the respective spring rates or is it to stiff to drive on the street? I'm always looking for cheaper quicker solutions for lifting these trucks Link to comment Share on other sites More sharing options...
fiscus Posted March 20, 2007 Author Share Posted March 20, 2007 Are the f-150's coils the same diameter as the XJ/MJ? what about overall height versus installed height? and the respective spring rates or is it to stiff to drive on the street? I'm always looking for cheaper quicker solutions for lifting these trucks They are the same diameter (top & bottom) as XJ coils, they provide around 2.5" of lift. I drove My father-in-law's XJ with these on a 1.5 hr drive home from a trail ride & thought they rode excellent. Link to comment Share on other sites More sharing options...
Rokhound Posted March 20, 2007 Share Posted March 20, 2007 see cw build not say his is cheap but i think it might be what your looking for. i think he is running coil spacer and longer shackle in the rear. Or run ZJ coils and longer shackle in the rear would be a thought as well Link to comment Share on other sites More sharing options...
Pete M Posted March 20, 2007 Share Posted March 20, 2007 Different springs are only part of the lift. Don't forget about control arms, track bar, brake lines, etc. Also, doing an SOA using your 2wd leafs will net about an inch less than what a 4wd would, meaning the amount of lift from stock is the same, but 4wd will sit ~1 inch taller. So a 4wd doing an SOA will need 5-6 inches up front to match, you'd only need 4-5. Link to comment Share on other sites More sharing options...
mjeff87 Posted March 20, 2007 Share Posted March 20, 2007 I just swapped a set of junkyard 4WD leafpacks into my MJ, which was 2WD and had the stock packs. I was expecting the reported 1" in lift, but was presently surprised when I ended up getting 3" :D I did refurbish the packs, and pressed in all new eye bushings, though. I was planning on SOA when I swap axles out, but seeing I got 3" just from the packs, I might just stay SUA and use a long AAL to net 4" or thereabouts. How it sits now with the "new" leafpacks in it.....20.5" from center of hub to bottom of flare (still have to swap front springs and/or add spacers to level it, and get longer shocks and brakeline): Image Not Found Image Not Found Link to comment Share on other sites More sharing options...
Duner Posted March 20, 2007 Share Posted March 20, 2007 What year f-150 springs are you using? when I checked specs on a few different years they don't seem to be anywhere close other than diameter, ie they were shorter overall and twice the spring rate. Link to comment Share on other sites More sharing options...
87manche Posted March 20, 2007 Share Posted March 20, 2007 skyjacker sells a long AAL. Rusty's sells 4" leaf packs You could go SOA with a bastard pack with less arch in the pack. Perhaps steal some leaves from a SOA truck like a dakota. Link to comment Share on other sites More sharing options...
feerocknok Posted March 20, 2007 Share Posted March 20, 2007 What year f-150 springs are you using?when I checked specs on a few different years they don't seem to be anywhere close other than diameter, ie they were shorter overall and twice the spring rate. The spring rate is alot higher. I can't remember years on these. Late '70s maybe? Add-a-leaf and shackle would probably be your best bet in the rear. You can junkyard some leaf packs for add-a-leaves, and either extend your shackles or buy Chevy drop shackles to finish off the 4". Link to comment Share on other sites More sharing options...
fiscus Posted March 20, 2007 Author Share Posted March 20, 2007 What year f-150 springs are you using?when I checked specs on a few different years they don't seem to be anywhere close other than diameter, ie they were shorter overall and twice the spring rate. The info on the front end is here: http://www.lunghd.com/Tech_Articles/Sus ... t_Lift.htm It appears that they were '79 coils. We just put them on my father-in-law's XJ here is a recent photo of it in action: Link to comment Share on other sites More sharing options...
fiscus Posted March 20, 2007 Author Share Posted March 20, 2007 Different springs are only part of the lift. Don't forget about control arms, track bar, brake lines, etc. Also, doing an SOA using your 2wd leafs will net about an inch less than what a 4wd would, meaning the amount of lift from stock is the same, but 4wd will sit ~1 inch taller. So a 4wd doing an SOA will need 5-6 inches up front to match, you'd only need 4-5. So, you're saying that 2wd leaves sit lower than 4wd leaves? If I did an SOA using my existing springs I'd only net 4-5"?!?! Sounds like a PLAN! Yes, I know all about the front axle/steering end of lifting XJ/MJs, I was confused on the rear axle end of MJs; I've lifted many an XJ (and a couple TJs) in my garage. Link to comment Share on other sites More sharing options...
Duner Posted March 20, 2007 Share Posted March 20, 2007 Ok partsamerica.com indicates that the TRW CC782 and CC784 are XJ/MJ replacement springs and that CC816 spring for the 76-79 f-150 and bronco 4wd is similar height but much higher rate 271 vs 146 to 158 for jeep springs this woud probably yeild some lift 1.5 to 2.5 inches but the ride would be a bit rough. Link to comment Share on other sites More sharing options...
Rokhound Posted March 20, 2007 Share Posted March 20, 2007 here is mine with 2wd leafs on the rear Link to comment Share on other sites More sharing options...
fiscus Posted March 20, 2007 Author Share Posted March 20, 2007 Ok partsamerica.com indicates that the TRW CC782 and CC784 are XJ/MJ replacement springs and that CC816 spring for the 76-79 f-150 and bronco 4wd is similar height but much higher rate 271 vs 146 to 158 for jeep springs this woud probably yeild some lift 1.5 to 2.5 inches but the ride would be a bit rough. I have ZJ coils in my XJ & I thought this XJ with the above mentioned coils drove the same. It also did not have swaybars (removed) and I did not notice any body roll or even notice them gone on the road. It flexed great offroad still (it crawled right up & out of the ditch in the photo above on 33s, while others on 33s & 35s had to follow the rut). Link to comment Share on other sites More sharing options...
fiscus Posted March 20, 2007 Author Share Posted March 20, 2007 here is mine with 2wd leafs on the rear How much lift do you have? (could you measure to the flares from the hub centers?) This looks a little higher than I was wanting to go, if I go that high I'd want bigger tires & get less mpg (this is my daily driver; I have 2 trail rigs already...) Link to comment Share on other sites More sharing options...
Rokhound Posted March 20, 2007 Share Posted March 20, 2007 i will go out after bit and get this to you and i am running 33x12.5x15 Link to comment Share on other sites More sharing options...
Pete M Posted March 20, 2007 Share Posted March 20, 2007 It is hard to use someone else's numbers for rear lift due to variations in our old leafs. Just measure up 5.5 inches from where it is now. Link to comment Share on other sites More sharing options...
fiscus Posted March 20, 2007 Author Share Posted March 20, 2007 hmmm... I am wanting to stay under 5" lift definitely, so 5.5 rear would be more than I want... Could I take out the smallest stock leaf if my lift is too high with an SOA, or would that compromise the pack? I'm thinking it would. Link to comment Share on other sites More sharing options...
Rokhound Posted March 20, 2007 Share Posted March 20, 2007 i am going to have to agree with Pete but from center on the axle to the top of the fender flare is 29" or so. Link to comment Share on other sites More sharing options...
Pete M Posted March 20, 2007 Share Posted March 20, 2007 hmmm... I am wanting to stay under 5" lift definitely, so 5.5 rear would be more than I want...Could I take out the smallest stock leaf if my lift is too high with an SOA, or would that compromise the pack? I'm thinking it would. No no no. You would have a 4.5" lift because you are using the 2wd leafs. But it'll be 5.5" taller than it is right now. Lifts out there should be made with the 4wd in mind. Plus, do NOT remove the overload leaf. The springwrap will be horrible. Link to comment Share on other sites More sharing options...
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