SW86 Posted August 27, 2010 Share Posted August 27, 2010 i searched here and didnt find what i was looking for but know someone has posted this here or maybe a cherokee forum :hmm: anyway ive found a 95 cherokee with a 8.25 rear end i can get for cheap. how easy is it to swap in though? i can get the spring perches rewelded no problem but is there any other things ill have to do? thanks Link to comment Share on other sites More sharing options...
Geonovast Posted August 27, 2010 Share Posted August 27, 2010 You'll need to swap the brakes over, so it's a good time to get new brake cylinders. You may have driveshaft problems, as the yoke on the 8.25 is a bit further forward than the D35. Obviously you'll need new U-bolts for the 8.25. I believe your spring plates will be fine. Link to comment Share on other sites More sharing options...
mvusse Posted August 27, 2010 Share Posted August 27, 2010 Yes, the spring plates will work. U bolts should never be re-used anyway, just make sure you get them for the larger diameter tubes on the 8.25". Even though the housing is a lot more stout, the axle shafts in that axle are almost as thin as D35 shafts. a 1997 or newer 8.25" would be a much better upgrade. Link to comment Share on other sites More sharing options...
JACKED88 Posted August 27, 2010 Share Posted August 27, 2010 Not sure why Geonovast said you'll have to change the brakes. If they need to be changed you might as well go disc. With a little modification the rear disc off a ZJ will work on a 8.25. All you have to do is open up the hole in the center of the backing plate to fit over the larger bearing housing. As for your perches, they'll need to be relocated to 42". (center hole to center hole) Pretty sure the front or pinion of the 8.25 is 1 inch longer than the 35. Do you have a lift? If so, how much? If you have enough lift that inch probably won't hurt you. (Lift increases the distance from the trans to the pinion) If stock height, you'll probably need to cut your shaft about an inch. The only other required mod that comes to mind has something to do with the e-brake cable and what you have to do to hook it up. I don't remember exactly what has to be done but I think it has to do with the MJ and XJ having different length cables and cable ends. (don't hold me to that) I have a 8.25 sittin in my garage waiting to be installed. I ask all the same question prior to buying it. Hence my being able to answers some of your questions. Good luck with it. Link to comment Share on other sites More sharing options...
mvusse Posted August 27, 2010 Share Posted August 27, 2010 :agree: He pretty much summed it all up I run an 8.25" with ZJ disc brakes. Zip tied the height sensing valve almost straight up because disc brakes require more pressure. I had problems with the parking brakes rusting away and/or falling apart, so I tossed them. As far as I am concerned, they are optional with an automatic transmission. Maybe at some point I'll install an aftermarket parking brake that uses the disc rotor instead of being a drum brake inside the rotor hat. Link to comment Share on other sites More sharing options...
SW86 Posted August 27, 2010 Author Share Posted August 27, 2010 thanks guys, I'm still waiting to hear back from the guy. might want to sell the whole jeep but with a soon to be shot 4.0 and dying tranny i don't see myself making an offer or taking one lol. i might have a few more ?s if the deal goes down :cheers: Link to comment Share on other sites More sharing options...
bikerdude661 Posted August 31, 2010 Share Posted August 31, 2010 I had my Dana 35 blow up on me a couple months ago, shattered the ring gear and tore the rest of it to shreds. I ended up finding a chrysler 8.25 in a 95 cherokee that was sitting at the boat yard here for scrap. so i pulled it out, had my boss cut off the perches with his plasma cutter and we welded them to the top of the axle. and everything lined up perfect, driveline and all, and it was even the same gear ratio as my front axle! though i didnt hook up my ebrake i just used the lines on it bled em, and called it a day. so i guess what I'm saying is, you shouldnt have any problems, its really straight foward good luck man! :cheers: Link to comment Share on other sites More sharing options...
Rymanrph Posted August 31, 2010 Share Posted August 31, 2010 I used the e-brake cables that came on the Comanche and the brakes that came on the axle. Mine is a 2001; new perches and I was good to go. Link to comment Share on other sites More sharing options...
SW86 Posted February 24, 2011 Author Share Posted February 24, 2011 alright so ive got my 8.25 now i need to know a few more things. do i just get perches for a 3" tube and what length, if theres a choice. i figured longer the better what angle do i set the axle at? I'm sure ill figure out where to make shock mounts but how did you go about mounting yours? i know i have a few more questions but i can't think of them. if you have anything else to add about this swap, please do so! :cheers: Link to comment Share on other sites More sharing options...
Geonovast Posted February 24, 2011 Share Posted February 24, 2011 Get factory perches from the dealer. They'll be for the correct tube size, actually shouldn't be expensive, and length will be fine. Shocks aren't an issue if you're staying SUA. The spring plates in the MJ are what the shocks mount to. Set the pinion angle the same as the D35. Link to comment Share on other sites More sharing options...
mvusse Posted February 24, 2011 Share Posted February 24, 2011 For SUA, factory perches are fine. For SOA, I used these. Link to comment Share on other sites More sharing options...
Rymanrph Posted February 24, 2011 Share Posted February 24, 2011 I got my spring perches from Summit. Part# DCC-4120074. $12.88 + $4.95 shipping. http://www.summitracing.com/parts/DCC-4120074/ Link to comment Share on other sites More sharing options...
flint54 Posted February 25, 2011 Share Posted February 25, 2011 Regardless of where you get your perches, let me suggest you find an accurate way to measure angles. Need to know the angle of the T-case or T-mission output shaft, the angle of the drive shaft, and the angle of the pinion. pinion angle should be very close to parallel that of the output shaft. On my 8.25 swap, the Tcase shaft was +5deg, the d-shaft was +7deg, and the pinion was +4.5 deg. Need to measure with the axle assy in place because the spring surface is not necessarily level. Link to comment Share on other sites More sharing options...
SW86 Posted February 25, 2011 Author Share Posted February 25, 2011 good deal. thanks guys. I'm going spring over finally. I'm guessing that 42" center hole to center hole is correct? also fellas while i was taking off the old brakes and getting it ready for the disc conversion, not one but BOTH of those little spider gears fell out! i thought it didnt move but i guess it did when i was taking that $#!& off. anyway how am i supposed to go about getting it back right?? Regardless of where you get your perches, let me suggest you find an accurate wayto measure angles. Need to know the angle of the T-case or T-mission output shaft, the angle of the drive shaft, and the angle of the pinion. pinion angle should be very close to parallel that of the output shaft. On my 8.25 swap, the Tcase shaft was +5deg, the d-shaft was +7deg, and the pinion was +4.5 deg. Need to measure with the axle assy in place because the spring surface is not necessarily level. did you make new shock mounts or did you just stay SUA? Link to comment Share on other sites More sharing options...
flint54 Posted February 25, 2011 Share Posted February 25, 2011 I stayed SUA. Suggest getting the axle assembly exactly where you want it, then tack weld those perches before moving from truck. Them remove and finish the welds. Also a good time to ditch the open gears and put in something that will drive both wheels. I put in the Powertrax no-slip, but haven't gotten to enjoy it yet as I'm still fiddling with the disc brakes. Also taking this opportunity to scrub, ospho, and undercoat the underside of the bed and frame rails while I'm in there. Link to comment Share on other sites More sharing options...
SW86 Posted February 25, 2011 Author Share Posted February 25, 2011 yeah I'm thinking limited-slip but funds don't support that idea right now. if i can't get those spider gears back right then i guess ill do something but until then..... about the disc brake conversion. I'm pretty sure on what i need to grab from the ZJ but does it matter the year i get it off of? or axle? i havent been to a couple JYs but the ones i have been to don't have many to choose from. ZJs that is. Link to comment Share on other sites More sharing options...
mvusse Posted February 25, 2011 Share Posted February 25, 2011 Do not believe it matters much, but remember what year you get them from. I believe 93 is different from 94 through 98, so you need to know when buying pads or rotors. Also the center hole needs to be enlarged to fit the larger axle tube. Aside from that they are a direct bolt on. Link to comment Share on other sites More sharing options...
SW86 Posted February 26, 2011 Author Share Posted February 26, 2011 doesnt the backing plate off a liberty fit already on a 8.25 since thats what some had? not like ill find one in a JY around here but just incase i do. aside from that, my 8.25 is now ready for perches/shock mounts monday. had to grind for about thirty minutes after the torch had its way :brows: so for a wrap up, i set the perches 42" apart but what about that dang pinion angle??? I'm using stock 4wd leafs surely one of you knows what you set yours to. I'm sure ill know what looks "right" when I'm about to do it but being almost exact is where id like to be. as for shock mounts, i can figure them out on my own. Link to comment Share on other sites More sharing options...
mvusse Posted February 26, 2011 Share Posted February 26, 2011 If you're using a driveshaft with a single u joint on each end (like the stock driveshaft), the pinion angle is supposed to be parallel to the transfer case output. Actually, you can go 2 degrees or so lower so it will be parallel when under load driving around. Link to comment Share on other sites More sharing options...
SW86 Posted March 6, 2011 Author Share Posted March 6, 2011 i was putting on the backing plate so i decided to test out the caliper to see if it would line up right with the axle shaft and it doesnt. theres no way in hell you could put a rotor on there. its about a 1-1/2 to 2 inches off. whats the deal?!?! all the write ups ive read said it was a straight bolt on and it is but doesnt line up. Link to comment Share on other sites More sharing options...
Pete M Posted March 6, 2011 Share Posted March 6, 2011 got photos? Link to comment Share on other sites More sharing options...
SW86 Posted March 6, 2011 Author Share Posted March 6, 2011 welp i got it. it just wasnt seated right on there. i guess with me in a hurry to finish grinding the backing plates and helping put down a tile floor i got caught up in the mix of things. just needed to step back and take a breath :rant: 8) as for an update. ive got everything ready to go get welded and disc brakes now on. I'm going to install the long arms on the 4.5 lift, see if i gain anything, then do the rear swap and up the front to 6, 6.5 maybe. can't wait! does anybody even make 6" springs anymore??? Link to comment Share on other sites More sharing options...
Pete M Posted March 6, 2011 Share Posted March 6, 2011 if you've already got the hellcreek 4.5s, you can probably get away with a longer shackle for that extra bump. Link to comment Share on other sites More sharing options...
flint54 Posted March 7, 2011 Share Posted March 7, 2011 I'm nearing completion (waiting for a couple odd minor parts) of my 8.25 + rear disc mod. I used backing plates and calipers from a 1997 ZJ. Two things needed attention;, the backing plate center holes needed to be opened up about 0.010" (I used a 3" sanding drum on a drill press), and the mounting studs on the axle tube ends needed to be replaced with the ZJ studs to account for the thicker backing plate. Other than that, it's all bolt-on. Also, I found this link: http://www.vibratesoftware.com/html_hel ... Angles.htm to be very helpful to understand the relationship between pinion, d-shaft, and output shaft angles. Parallel is good, and there's a couple other factors. Also had to revise the brake lines a bit, and there's a number of ways to do it. Link to comment Share on other sites More sharing options...
SW86 Posted March 7, 2011 Author Share Posted March 7, 2011 ahhh i don't really like the spring under. never have. i constantly drag those things on everything but at least they take the beating i guess. I'm still going to run it for awhile because i do like the ride height. thanks again flint. i also got mine from a 97 zj. forgot to grab the mounting studs but I'm going back for them this week. as for brakelines I'm just going to buy new hardlines a tad shorter to help build a bit more pressure maybe. Link to comment Share on other sites More sharing options...
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