gildo Posted February 14, 2007 Share Posted February 14, 2007 Gents, below are some questions about my diffs, tranfer case and transmission, just looking for some expert assistance here on ID, specs etc. My MJ is an 86 XLS, V6 auto Selec-Trac The transfer case has a New Process tag, and is stamped with the following- Model: AM 228 Assy: 89530 03970 Serial No: 123 (Mounting screw) 86-1 Ratio: 261 Is this transfer case any good or just a boat anchor? The front diff looks like a D30 (Similar to my 98 XJ), dosent have Vac disco set up, but does have rubber boots covering between the inner and outer axles? The rear diff Is also similar shape to my 98 XJ, 10 bolt round lid so I'm guessin its a spring under D35, with the load sensing valve above? Another Question is - Any idea what my Ratios may be if still stock? Auto Transmission is 3spd?, and from below the pan looks rectangular (long sides front and back) with the left rear corner cut off. Is there somewhere I can post pics here? Might make it easier for you clever doods to ID all this stuff. Cheers Michael Link to comment Share on other sites More sharing options...
Kenosha Warrior Posted February 14, 2007 Share Posted February 14, 2007 Gents, below are some questions about my diffs, tranfer case and transmission, just looking for some expert assistance here on ID, specs etc. My MJ is an 86 XLS, V6 auto Selec-Trac The transfer case has a New Process tag, and is stamped with the following- Model: AM 228 Assy: 89530 03970 Serial No: 123 (Mounting screw) 86-1 Ratio: 261 Is this transfer case any good or just a boat anchor? The front diff looks like a D30 (Similar to my 98 XJ), dosent have Vac disco set up, but does have rubber boots covering between the inner and outer axles? The rear diff Is also similar shape to my 98 XJ, 10 bolt round lid so I'm guessin its a spring under D35, with the load sensing valve above? Another Question is - Any idea what my Ratios may be if still stock? Auto Transmission is 3spd?, and from below the pan looks rectangular (long sides front and back) with the left rear corner cut off. Is there somewhere I can post pics here? Might make it easier for you clever doods to ID all this stuff. Cheers Michael 228 has a viscous coupler, does it not? (Eagle/DirtyManche?) Autobox is a 3spd 904 Chrysler, or 999? Should be a 904. Link to comment Share on other sites More sharing options...
DirtyComanche Posted February 14, 2007 Share Posted February 14, 2007 Gents, below are some questions about my diffs, tranfer case and transmission, just looking for some expert assistance here on ID, specs etc. My MJ is an 86 XLS, V6 auto Selec-Trac The transfer case has a New Process tag, and is stamped with the following- Model: AM 228 Assy: 89530 03970 Serial No: 123 (Mounting screw) 86-1 Ratio: 261 Is this transfer case any good or just a boat anchor? The front diff looks like a D30 (Similar to my 98 XJ), dosent have Vac disco set up, but does have rubber boots covering between the inner and outer axles? The rear diff Is also similar shape to my 98 XJ, 10 bolt round lid so I'm guessin its a spring under D35, with the load sensing valve above? Another Question is - Any idea what my Ratios may be if still stock? Auto Transmission is 3spd?, and from below the pan looks rectangular (long sides front and back) with the left rear corner cut off. Is there somewhere I can post pics here? Might make it easier for you clever doods to ID all this stuff. Cheers Michael Selec-trac MJs are ultra rare - I think. The 228 is apparently an 'alright' case too, providing you don't run into vacuum issues. It has a fixed yoke on the rear as well. They threw them in the FSJs behind 360s - so they gotta be reasonably strong. I'm not sure on how they work - I've never had one apart. You have CV shafts in your D30. They're bad. Like to go pop and snap. How round is the diff cover? Egg shapped or perfectly round? If it is perfectly round, you scored an AMC20 - which are about as strong as a D44. If it's an egg shape, it's the D35 POS. And I'll say you have 4.10s. But I'm not sure. And you gotta upload pics to say photobucket, then link 'em. Unless we have a pic uploader I don't know about. Link to comment Share on other sites More sharing options...
Kenosha Warrior Posted February 14, 2007 Share Posted February 14, 2007 round with 10 bolts = AMC20 = kickarse axle, ultra rare. Link to comment Share on other sites More sharing options...
Eagle Posted February 14, 2007 Share Posted February 14, 2007 The 228 and the 229 are essentially the same transfer case, but the 229 had a viscous coupling and the 228 has a mechanical differntial. It's a VERY heavy-duty t-case. It was used in some years in the full-size Cherokee/Wagoneers and J trucks. It's also a very HEAVY t-case. The biggest downfall is that there is no locked 4WD high range. This is basically an all-wheel-drive case. There's no 2WD mode, and the transfer case does not lock the front and rear driveshafts in 4WD high range. It was probably not original to your MJ. As far as I know, the 228 was the optional Selec-Trac case for the '86 XJ, but I don't think Selec-Trac was an option in the MJ. Link to comment Share on other sites More sharing options...
Eagle Posted February 14, 2007 Share Posted February 14, 2007 The rear diff Is also similar shape to my 98 XJ, 10 bolt round lid so I'm guessin its a spring under D35, with the load sensing valve above? Round, or oval? If it's oval, similar to the Chrysler 8.25 axles in later year Cherokees, it's a Dana 35. If it is perfectly round, it's the afore-mentioned AMC model 20 and a VERY desireable axle. What size are the rear brakes? If they are 10" x 1.75" the axle is probably a D35. If they are 10" x 2.5" it is probably a Model 20. Link to comment Share on other sites More sharing options...
gildo Posted February 14, 2007 Author Share Posted February 14, 2007 Thanks gents its been a great help, the transmission looks to be a 904, the bad thing is its set up for a V6 so not much good for any 4.0/258 project transfer is a 228 thats pretty clear, and must have been the factory option as the select trac badges and all match. The rear diff unfortunately aint an AMC20 I have one under the rear of my CJ so I'm quite familiar with them, and it looks to be a D35. Not many options of changing that without a lot of messin round with changing perches, tubes and axles. So if given the choice of the MY D30 front with CVs to build up or an XJ D30 with Unis, what would your thoughts be? I'm thinkin XJ with the MJ ratios. ??????? Link to comment Share on other sites More sharing options...
carnuck Posted February 15, 2007 Share Posted February 15, 2007 The 228 and the 229 are essentially the same transfer case, but the 229 had a viscous coupling and the 228 has a mechanical differntial. It's a VERY heavy-duty t-case. It was used in some years in the full-size Cherokee/Wagoneers and J trucks. It's also a very HEAVY t-case. The biggest downfall is that there is no locked 4WD high range. This is basically an all-wheel-drive case. There's no 2WD mode, and the transfer case does not lock the front and rear driveshafts in 4WD high range. It was probably not original to your MJ. As far as I know, the 228 was the optional Selec-Trac case for the '86 XJ, but I don't think Selec-Trac was an option in the MJ. Selectrac option was available with NP228 in '86. Only automatics came with them too. The nice thing about the 228 (and 229) is that you can drive them on any surface in 4 hi. My '87 was originally 2wd (hoping to cure that finally next week with an AX-15/NP208 swap) but I plan an AW4 and NP242 (it'll be nice to run 4 hi on the street. It already corners faster than a lot of the Hondas around here) swap later this summer when I have time to have it off the road for wiring swap, etc. Still need a column shift for the auto (I find 904 3 speed columns but they need modding and are crazy priced!) I have too many projects and not enough time to get to them all right now (I have a house to build and a job that takes a lot of my time) Link to comment Share on other sites More sharing options...
carnuck Posted February 15, 2007 Share Posted February 15, 2007 I'd keep the NP228 and if you go to a 258, get a 999 built up to put in front of it. You can get a 2wd one and use the guts of the 904 (output shaft and adapter sleeve mostly) You'll need to get a 4.2L with serpentine belt and run 4.0L fan, water pump, etc (not enough room for a waterpump mounted fan) and rad. You'll need to change the hood to double catch and the rad saddle from a 4.0L rig as well. Why do you want to change out the 4 cyl? Gutless with the auto? I'd convert to 5 speed and have fun (especially if it's fuel injected already) I'd guess 3.73 gears. Maybe 3.55 with the auto. You should be able to just change the axle shafts in the front. (I wonder if the CV joints from a Grand Cherokee with V8 are much stronger? I have a set of those around. Smoother cornering than Ujoint) Definitely a D35 rear. If you look at the left side of the front cover pic, the axle ID tag is still there. You might be able to read it carefully from the back. Link to comment Share on other sites More sharing options...
feerocknok Posted February 15, 2007 Share Posted February 15, 2007 I'm always lost as to if the V6s had 904s or 999s, but both are power robbers. Should be 4.10 gears If the 228 was popular in FSJ then there might be a kit to lock that center differential. Try and grab a front axle from the JY to swap that guy out. Link to comment Share on other sites More sharing options...
carnuck Posted March 22, 2007 Share Posted March 22, 2007 The 4 cyl and V6 got 904s. The inline 6 got 904 or 998/999. I can ship a 999 bare case for a 4.2/4.0L/AMC V8 pretty much anywhere (helps if one has friends in the shipping biz for overseas stuff though. I used to ship to OZ and NZ till UPS's prices spiked due to high fuel costs) The I4/V6 904's guts will mostly fit the 999 except the rear band and maybe the rear clutch drum (inline 6 trans got wider rear band) The tag on the RH side of this cover will say what ratio, but often the V6 3 speed auto came with 3.55 gears. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 22, 2007 Share Posted March 22, 2007 3.4 camaro engine. i tell that to everyone with the v6. as stated, selec-trac was an option, but only with that t-case. get rid of the cv front end and put a non-disco uni-front end from an xj with matching ratio. unfortunately regarding ratios, we can only go by guidelines...a original owner could have ordered something specific, so you will have to check that yourself. it should have tags (maybe on the rear...but if it has cv's on the front end then the front axle isn't original so maybe not) and if not, you can remove the cover and count the teeth. MORE PICS!!!! Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 22, 2007 Share Posted March 22, 2007 i eat my own words...after looking closer, it appears that that may be the stock front axle...it's beefier on some parts than the newer cv cherokees. i just made an @$$ of myself. Link to comment Share on other sites More sharing options...
87manche Posted March 22, 2007 Share Posted March 22, 2007 early selectracs did have CV joints. You can keep the axle and put new shafts in it. You may have to change out the knuckles, at the very least you'll have to get matching unit bearings. Link to comment Share on other sites More sharing options...
carnuck Posted March 22, 2007 Share Posted March 22, 2007 I was thinking about putting the ZJ CV axles (from a V8 rig) I have into my '87 so the 242 setup will be smoother on cornering (it's going to be the wife's rig unless she gets this instead Link to comment Share on other sites More sharing options...
feerocknok Posted March 22, 2007 Share Posted March 22, 2007 I was thinking about putting the ZJ CV axles (from a V8 rig) I have into my '87 so the 242 setup will be smoother on cornering (it's going to be the wife's rig unless she gets this instead Off topic but that to a Comanche at all! That's like 2 different extremes! Link to comment Share on other sites More sharing options...
carnuck Posted March 22, 2007 Share Posted March 22, 2007 She drives 2 miles to work and has to warm the car up first. Total waste of time and fuel. (in summer she plans to walk to work on nice days but her past leg injury may not let her) Link to comment Share on other sites More sharing options...
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