paully Posted May 19, 2012 Share Posted May 19, 2012 Hello All! My first post here at ComancheClub, coupled with my first project with my MJ! I've a '91, 2wd, long bed, 4.0, ax15. The ring gear of the dana 35 rear axle (3.07 ratio) has given up 6 teeth (3 on opposite sides). So as I've read in multiple threads somewhere here, i'll "use any oppurtunity to upgrade from a D35". In an ideal world, this first project of many, will end up with: 1. a stronger axle, with d44 with 3.55 ratio is the ideal (if i can find one), with suspension over axle to gain a couple inches, 2. a front lift kit to match. Concerning #1: - What range of vehicles and years are recommended for an "easyish" transition? Expecting a little grinding and welding. My relying on local salvage yard dudes to help me find something compatible isn't getting me too far. - Anything I need to be aware of with the drive shaft for the various vehicles recommended? - Where can I find the gear ratio on the axle/diff? I'd read that it's stamped on the ring gear. But I'm not finding it on mine, which just states "6 2490 DANA 42828 P8L71 43 14". Concerning #2: - The couple of inches gained by the SOA trick from #1, needs to be matched up front. What's the "most economical" (i.e. cheap), but not risking reliability, way to gain these couple of inches? Thanks! Link to comment Share on other sites More sharing options...
Backdraft Posted May 19, 2012 Share Posted May 19, 2012 First off, congratulations on the MJ and welcome to the club. Beer is in the fridge. To take a crack at answering your questions, well...... Vehicles for a donor axle I would look for would be another Comanche. That would be the easyishest (is that a word?). I'd also look for an XJ rear 8.25 29 spline. Fairly easy to adapt and 3.55 is the most common ratio. An Explorer 8.8 is also an option and you gain rear discs as well. Driveshafts will be interchangeable from another MJ if its the same as yours (swb/lwb/d35/d44/etc). Driveshafts are different lenghts for an XJ. But you may be able to use yours. The 8.8 has a mounting flange instead of a yoke IIRC. Of course if you go SOA, its all a wash anyway and you most likely will need your driveshaft reworked. And the numbers on your current ring gear, the 43 14. Divide those numbers and you get 3.07. There's your current gearing. As for concern #2. The "couple inches" gained from SOA is more like 5 to 6.5 inches. There really is no economical way to negotiate a lift for the front to match. Everything will need to be changed in order to do it right and safe. That includes springs, shocks, swaybar links, trackbar, control arms, brake lines, etc. don't forget if you change the rear gearing, the front needs to change to match. And at that height, my opinion will be drop brackets or long arms. Without one of these, the ride quality is going to suck. Hope that helps, and good luck. Link to comment Share on other sites More sharing options...
Jeep Driver Posted May 20, 2012 Share Posted May 20, 2012 http://knoxville.craigslist.org/pts/3023773011.html Link to comment Share on other sites More sharing options...
Jeep Driver Posted May 20, 2012 Share Posted May 20, 2012 There are some other local deals I was going to post but...... Look for a complete XJ as a donor, +-$600. This will give you trans, TC, front DS, linkage, and other goodies as well as front and rear axles. I would complete the swap and get it drivable then take the next step to a lift. Don't forget that the donor can be scrapped and you'll get most of your money back. Look for a donor with a non CAD front axle. Link to comment Share on other sites More sharing options...
Jeep Driver Posted May 20, 2012 Share Posted May 20, 2012 Before it get's asked or before some thinks what I said is counter intuitive...... Why get it drivable before the lift? As the other poster stated that there is no way to get to 5.5" economically, just the adjustable lower control arms and track bar will cost you a quick $500. Wheels+tires, shocks, springs, TB, CAs, etc....odds and ends.........steering components....New rear DS....longer brake lines...... and you can quickly be into this for $2500-$3000. You asked about an economical swap???? Most of the Dana axles I've seen will be tagged at the dif cover, if not there is a bill-of-material number on the tube and that number can be ran at Dana's website. Link to comment Share on other sites More sharing options...
Eagle Posted May 20, 2012 Share Posted May 20, 2012 Concerning #1:- What range of vehicles and years are recommended for an "easyish" transition? Expecting a little grinding and welding. My relying on local salvage yard dudes to help me find something compatible isn't getting me too far. - Anything I need to be aware of with the drive shaft for the various vehicles recommended? - Where can I find the gear ratio on the axle/diff? I'd read that it's stamped on the ring gear. But I'm not finding it on mine, which just states "6 2490 DANA 42828 P8L71 43 14". 43 and 14 are the tooth counts for the ring gear and the pinion gear. Divide 43 by 14 and you get 3.0714. Easy-"ish" upgrade would be any XJ axle that's a Chrysler 8-1/4. An XJ or MJ Dana 44 would be ideal, of course, but VERY unlikely to find. The Chrysler axles are much more common. 1990-1996 the Chrysler axle has the same shaft diameter and spline count as the Dana 35 but the housing and tubes are stronger. 1997-2001 the Chrysler axle got larger shafts with a higher spline count and are virtually equal to the Dana 44 in strength. All that's needed to install an XJ axle in an MJ is to cut off the spring perches and re-weld them in the correct location for an MJ. Concerning #2:- The couple of inches gained by the SOA trick from #1, needs to be matched up front. What's the "most economical" (i.e. cheap), but not risking reliability, way to gain these couple of inches? Doing a spring-over conversion won't gain you a "couple" of inches. It will be 5-1/2 inches minimum, possibly 6. To match that in the front you should be looking at: [*:3auzvas8]Lift springs[*:3auzvas8]Adjustable upper and lower control arms, or long arms[*:3auzvas8]Sway bar disconnects[*:3auzvas8]Much longer shocks (front and rear[*:3auzvas8]Adjustable track bar[*:3auzvas8]Steering box brace If what you really want is a couple of inches, do an add-aleaf in the rear springs and 2" lift spacers in the front. Link to comment Share on other sites More sharing options...
jeepcoma Posted June 2, 2012 Share Posted June 2, 2012 As the other poster stated that there is no way to get to 5.5" economically, Agree on that one, if you're just looking for a bit of height and it's going to be a street truck I'd upgrade the rear springs to the Metric Tonnes and the front to ZJ V8 springs (possibly with a 1" spacer which I am contemplating since my bed is empty most of the time and would give it better balance). That's what I've ended up doing on my '91 with stock tires, D44 w/3.55 gears and AX15 and it's a great street driver. 1st gear is very potent and makes hill starts easy. Check out mybuild thread! Might give you some ideas (or let you know what you're getting into!). Congrats on the MJ, looks pretty rust free. Link to comment Share on other sites More sharing options...
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