streetjeep2.5 Posted December 21, 2009 Share Posted December 21, 2009 My 87 4x2 MJ has one piece hub/rotor. I need to replace them. Is the spindle and calipers the same on my 87 and the MJ's with separate hub and rotor, or do I need to swap spindle, caliper, hub and rotors? Link to comment Share on other sites More sharing options...
Eagle Posted December 21, 2009 Share Posted December 21, 2009 The calipers should be the same (although I have heard conflicting reports on this) but you have a conventional spindle and wheel bearings, and the ones with a separate hub/bearing unit do not have a spindle at all. The hub/bearing unit alone costs over $100 (and IMHO it would be foolish to buy a used one because it could fail on you next week), so I don't see much point in trying to make this conversion. To change over, you'll have to pop your ball joints and replace the entire knuckle. Seems like a lot of work when the conventional spindle is probably the better system if you don't have 4WD. Link to comment Share on other sites More sharing options...
freakjeep93 Posted December 21, 2009 Share Posted December 21, 2009 excuse my ignorance but whats the difference? Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted December 21, 2009 Author Share Posted December 21, 2009 excuse my ignorance but whats the difference? Since to change the rotor om my 87 4x2 I have to replace the whole assembly because I have a one piece, if I could do a direct replace with a two piece and not have to change anything else and the price was pretty much the same, if I ever had to replace a rotor again since I plan on keeping this mj until they take my license away when my age is a factor, I would only need to buy a rotor and not the whole assembly. Link to comment Share on other sites More sharing options...
Geonovast Posted December 21, 2009 Share Posted December 21, 2009 Unless you ever plan on going to 4wd... it's not worth the hassle. As Eagle said, those unit bearings are over $100 a piece, you'll need the dummy stub shafts to go in them, which won't be easy to find, you may need new calipers(I've heard conflicting reports as well, but when I took the 2wd beam off a 91 and put a 94 D30 on, I had to change calipers), and you'll need rotors too, which are at least $18 a piece. Seems an awful lot of work to maybe save $60 down the road. Just change your pads around 40%, and you shouldn't need new rotors. Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted December 21, 2009 Author Share Posted December 21, 2009 went to http://www.partswebsite.com/hendrickmop ... ts&start=1 and they list for 86 4x2 the same knuckle and caliper for an 87 4x2 and for the 86 either one or two piece hub and rotor. Soooo... from this I would ASSUME ;) an 86 two piece from a 4x2 would fit an 87 4x2. If I read it correctly, they did not show a difference in wheel bearings, so maybe at some point in 86 the went from two piece to one piece until returning to a two piece in the 1990's. Doesn't make sense to completely change the whole design but just make a two piece a one piece and keep every thing else unless there was a serious design flaw in the two piece. I will do a bit more research. Again , thinking only of future repair costs. Link to comment Share on other sites More sharing options...
mjeff87 Posted December 21, 2009 Share Posted December 21, 2009 I plan on keeping this mj until they take my license away when my age is a factor  that's sig worthy right there....  Jeff Link to comment Share on other sites More sharing options...
JeepcoMJ Posted December 21, 2009 Share Posted December 21, 2009 84-86 xj/mj 2wd front axles used 4wd knuckles and wheel bearings. then, in 87, they switched to spindle style for 2wd. in the later 90's I've heard some reports that they went back to 4wd style. Â Â but...to use a 4x unit bearing and discs, you MUST have the 2wd stub shafts. Â Â 4x unit bearings are NOT capable of holding themselves together without a shaft bolted in them. you can't drive without a shaft in them..it WILL seperate, causing the wheel to fall off, and bad things. several jeepers who have broken axle-shafts out wheeling have not thought to keep the outer stub in, and have attempted a drive home without the stub shaft in. at least a couple deaths have resulted. Â Â Â the 2x stub shaft is hard to find. I have a few of them...and they're not going anywhere. I keep them for when I break a ujoint on the trail and need to drive home w/o a shaft...unlike broken 4x4 stubs, they don't have ears on them for ujoints...thus they are centrally balanced, and this will prolong the life of the unit bearing so I won't wreck it on the way home. Â -Pat Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted December 21, 2009 Author Share Posted December 21, 2009 4x unit bearings are NOT capable of holding themselves together without a shaft bolted in them. you can't drive without a shaft in them..it WILL seperate, causing the wheel to fall off, and bad things. several jeepers who have broken axle-shafts out wheeling have not thought to keep the outer stub in, and have attempted a drive home without the stub shaft in. at least a couple deaths have resulted. Â Â Don't want THAT to happen! Guess I will abandon this attempt :brows: Link to comment Share on other sites More sharing options...
Geonovast Posted December 21, 2009 Share Posted December 21, 2009 I have a few of them...and they're not going anywhere. I keep them for when I break a ujoint on the trail and need to drive home w/o a shaft  We did have some carnage though... Pat managed to break a u-joint on the passenger side while backing off a snow hill on the edge of my street. Had to pull the shaft, and leave the stub... He has pics. How someone toasts a u-joint THAT BAD while doing so little is pretty good.  :popcorn: Link to comment Share on other sites More sharing options...
WBKrazy Posted December 21, 2009 Share Posted December 21, 2009 not worth it, IMO.... 4 wheel bearings @ $10.00 apiece, 2 $3.00 grease seals, and 2 $35.00 rotors (at least thats what they were when i replaced mine) still doesn't add up to what one hub style bearing costs if it does go bad... Link to comment Share on other sites More sharing options...
carnuck Posted December 22, 2009 Share Posted December 22, 2009 Before I made mine 4x4, I had the 1 piece rotors (still have them tucked away to make a trailer axle one day) and thought about getting Rambler drum hubs to see if the rotors would pop on for the 4x4 version. Jeep changed the calipers in late '91 which is why some have to change over when converting to 4x4. Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted December 22, 2009 Author Share Posted December 22, 2009 not worth it, IMO.... 4 wheel bearings @ $10.00 apiece, 2 $3.00 grease seals, and 2 $35.00 rotors (at least thats what they were when i replaced mine) still doesn't add up to what one hub style bearing costs if it does go bad... What brand of hub/rotor combo did you get that only cost $35? I have seen some on websites for even less than that, but have wondered about quality. Posted at another time asking about the quality of Winmere (think that's it) but received zero responses. What about Brembo (think that's the brand)? Link to comment Share on other sites More sharing options...
carnuck Posted December 22, 2009 Share Posted December 22, 2009 Brembo are good, but come in regular and performance versions. Link to comment Share on other sites More sharing options...
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