Incommando

On topic would be a recent Four Wheeler/JP article ranking the best axles for a jeep swap. They ranked the AMC M20 as used in the FSJs and MJs ahead of the vast majority of D44 rears and among the best of the 1/2 ton axles.

A 265/70/15 is about 30" tall and 11" wide. The more common 265/70/16 is about 31" tall and 11" wide. It is only .5" wider than the very common 31x10.5x15 so I don't really see the MJ being "too light" for that width. I had no issues at all on road or off in my MJ on the same width tire (265/75/16) in 5-6" of snow this week. Never heard of a 235/80 but there is a 235/85/16 that is roughly 32x9. I ran 265/70/16 M&S rated Firestone Wilderness LT tires on my truck when it was 2wd and it was much worse in the snow than it is now in 2hi. The difference is the tread design only. "Snow tire" & "M&S rated" mean very little as far as how well a tire will actually perform.

285/75/16's usually measure less than 33" tall and nearly 11.5" wide. The closest in a metric would be 255/85/16 which are about 33.5 x 11. As posted above Swampers are one of the very very few tires that measure up to their height claims so the 285's would be 1.5" shorter on average. I have run Swampers in 32x9.5 on a couple of jeeps. I kept a set to throw on my first MJ for off road use. For my area the tall skinnies work very well off road. But the traditional Swampers suck on road and that is why I do not have them on my current truck. I knew I would not be off road enough to justify them.

RockAuto has some higher end choices that are a lot cheaper than the better ones that I can buy locally. I do not know what duties and shipping to the Great White North may do to that savings, though.

Rockfrog, Check the last page of my build thread in my sig. I have the chevy drop shackle/ 2" puck metric ton combo with 31's. had the 31's stock too. Could not be happier with the 2". I use the truck as a truck and not an off road toy. That sounds like a good combo to keep the other stock suspension and steering goodies in good shape. Replacing that stuff adds up fast.

For the first 4 years I owned this MJ it was 2wd and I parked it for the winter here in Ohio with no negative effects. Now that it is 4wd it is not parked for the winter. Nothing ever happened to it but of course I am 100% faithful to my girlfriend. To my wife on the other hand..... :brows:

New owner? Abandon hope all ye who enter here :banana:

The HMMWV center sections changed about 20 years ago. They had been running an AMC20 with a Torsen T1 in it. Don't know about the replacement, as it didn't interest me beyond it not being a T1, but it was brought about by cost... Torsens aren't cheap to manufacture unless you're doing it in Eastern Europe. I've been wondering about trying to put something together with an old HMMWV T1 and an MJ AMC20, in an attempt to get a factory-esque Torsen rear diff into an MJ. Trouble is, the HMMWV achieves its final drive through the gearing in the portals, and the diff runs something like a 2.7 ratio, which is below the cut-off line for gear sizes on a regular AMC20 carrier. I don't know if it would be possible to even have reliable gears for a more practical ratio custom made for the Torsen carrier. Having a custom Torsen carrier made would be prohibitively expensive... we're talking several days worth of machine time. For anyone interested a new Gleason/Torsen principle limited slip for an AMC20: http://www.jegs.com/p/Detroit-Locker/Detroit-Truetrac-Differentials/1032953/10002/-1 That does suck as the Model 20 uses, as you know, one carrier for 2.73:1 and down and another for 3:08:1 and up. I could not imagine the cost of fabbing a custom carrier but I bet it would be more than the new ones listed above which run around $600. No they are not the actual Torsen T-1. I also don't know if a simple solution such as the "thick" gear sets available to run 3-series D44 carriers with 4-series gears has ever been explored. If so then perhaps a spacer would mate it all together. Who knows? The AMC Model 20 internals were supposedly used on at least the first 10 years ( starting in '84??) or so in both the front and rear of the Humvee. Although not a Humvee the AMC 20 internals were for sure used in the H1 its entire run. The housings may or may not have been aluminum that whole time. From what I have read the diff troubles started with the practice of "up-armoring" the vehicles and increasing the weight much beyond what should be asked of a 1/2 ton diff and the original design parameters spec'd to AM General in 1979. Add in that the diff was spec'd for the 6.2L non-turbo diesel that got replaced by the 6.5L turbodiesel. That would also increase the strain on the diff and possibly result in a design change for the later models and/or an increase in failure rates for a diff originally spec for the other engine and GVWR. A diff that is pretty darn good for a Cj/MJ/SJ/J10 might give a different impression in a newer Humvee. The Humvee itself has nearly doubled in curb weight since its '84 debut @ 5,400 #'s to today's 11,200 #'s on average. For Am General to have used the almost in-house M20 internals in its '79 design would not be a surprise. As the IFS/IRS design on the Humvee removes much the load from the diff by it being mounted to the chassis and therefore not part of the structure supporting the weight of the vehicle like a traditional semi-float axle assembly's diff I could see the internals being deemed sufficient ( and cost effective ) for the original Humvee roll-out. Back story: AM General was the sister corporation to AMC when the contract was bid. It was originally a division of Kaiser Motors created for government contract vehicles and stood along side of the Jeep division. Think Buick/Chevy. The Legendary M715 so often called a Jeep was not technically a Jeep but an AM General product the way a skylark is not a chevelle although both are GM. You can see that it does liberally use the same parts as the Jeep Gladiator of the time including jeep stamped parts, though. When AMC bought Jeep from Kaiser in 1971 it spun AM General off into a separate corporation also owned by AMC and not just a division of the same company as under Kaiser. AMC sold Am General to LTV in 1983 before Renault gained controlling interest in AMC so AM General was not part of either Renault, Chrysler, Mercedes, or Fiat control. And some AMC 20 info: http://www.ringpinion.com/technicalhelp/ContentFrame.aspx?FilePath=~%2FContent%2FHowTo%2FGeneralInfo%2F%2FDon%27t_Throw_Away_That_Model_20_Rearend_Yet.inc

Ya posted while I was typing...:)

The entire front sheet metal will transfer: doors, hood, cowl, fenders, header panel, grille, flares, and the lights/lenses. The front bumper is the same but the rear bumper is not. As the doors are physically a 100% bolt-on swap over and IIRC the window controllers on a '91 XJ are on the door panel then all you would need to do is wire the juice and the connection from the driver's door to the passenger door if I am not mistaken.

It depends on what you are looking at. The AMC Model 20 is actually the version used under CJ's. It has two-piece axle shafts that are problematic. The MJ & FSJ line used what is technically the AMC Model 23. It for sure has factory one piece axles and according to one photo I saw the tubes are thicker than on the CJ version. If it is an actual MJ version I would snag it in a heart beat if the price for the axle was not stupid expensive as they are getting scarce and are pretty cool. IIRC they were only available in the MJ one year but it may have been two. This MJ version is on par with the other half-ton axles like a D44. The center section internals are as good as anyone's. In fact they used the center sections in the Humvees that AM General produced for the government for 20 years after AMC dropped the axle in 1985. They do benefit from trussing and welding the axle tubes to the housing to prevent spinning. But most axles would benefit from these steps. The downside is the cost and availability of good upgrade parts for them in many cases. A D44 would probably have the edge in this area. If you just want to replace a D35 the cheapest route is usually an XJ 29-spline 8.25 but the Later Explorer 8.8 has a lot going for it. I would not pay a premium price over an 8.25 or 8.8 for an XJ or MJ D44 just because they were factory in some models. But that is for the buyer to decide.

I drove through KY, TN, NC, and SC on my way to spend a week on Hilton head in October. You guys had the cheapest gas of any of the 5 states that I was in.

On mine it was the CPS. It got progressively worse and eventually starting stalling. I replaced the CPS and it corrected all of the problems including the random misfire at idle just as you describe. Considering that many aftermarket CPS units seem to have a higher failure rate than the original I would not rule that out as a culprit even if it has previously been replaced. I will point out that I have a '91 HO and not a Renix so that may make a difference.

I used the longer Barnes 4x4 perches. Neither in nailing on pavement nor any off-road obstacle yet encountered has resulted in spring wrap. As for the leaf pack: I have not seen a post about making such a spring pack with definitive results. They very well could be out there but it looks like you might just have to do it & follow the trial and error method to get what you want. I used 2wd rear springs and got about 5.5" of rear lift when swapping in a similar 8.25. Had I used a shorter perch like the stock style or popular Mopar set ( maybe .25" lower than my choice) and XJ shackles (- .5" over MJ shackles) with my 2wd leaves I may have wound up between 4.5-5"... but that is just on paper as I have not tried it.

Death Wobble is extremely violent. Their is no mistaking something else for it. You will be locking your brakes up to stop it as it feels like your front axle is trying to leave your jeep.

RE-Rubicon Express. Formerly a stand-alone company it has since been absorbed by conglomerate Transamerica which makes/owns smittybuilt,pro comp, and dozens of other product lines. The also own quadratec and 4wd hardware as well as other mail-order houses. And people think they are competing against each other.... RE's reputation is so far not tarnished by the ownership change. Others have not fared as well. I had always heard that 32's and 3.55's would make an XJ/MJ into a dog. I have not found this to be true, either. Both on-road and off-road this combo performs well. Is it optimal for off-road use? Not at all. But it is not a hard-core wheeler and I built it with that in mind, as you suggest. At 5.5" of lift and 32" tires I probably only sit .5 inch higher than a 33/4.5 combo so I am not much worried about that. Although I did go with an adjustable track bar and uppers to get the geometry back correct I have not encountered any other issues that I did not have with my 4.5" RC kit. Yet, anyway. And speaking of that kit: My personal RC complaint, besides a harsh ride, was being IMHO ripped-off by RC. To support a CC supporter I purchased my kit through Hellscreek, an official RC dealer. I could have got about the same price elsewhere when discounted shipping available online was factored it but it was less then $10 difference. RC advertises that the kit contains certain items including extended sway bar links. Mine had none . I contacted Hellscreek and they verified that the links are listed and included. They try to make it right. RC tells them to pound salt. I call RC directly. They explain that although they do indeed list them on their website as well as on the packing list that came with the kit they do not actually include them and the advertising is just outdated. I found this to be more then slightly deceptive. They refused to honor their own website's promises. I have checked randomly in the intervening years and not once have these crook's changed their parts list to delete those links as being included in the 4.5" kit. Outdated advertising my @$$. When I posted my story on here there was no shortage of people who, like me, had personal stories ( not internet rumors) of being shafted by these shysters. There is also no shortage of people with personal experiences complaining about the ride quality of their kits. Can other individual pieces from RC be okey-dokie? Maybe. That is probably especially true of items that RC simply re-sales as with those "RC" springs from that Canadian manufacturer that makes many such rear springs for private label sales if I am correct. But I will never knowingly give those liars another dime and recommend that others do not, either. Your actual mileage may vary.

If he continues on to 70 mph I don't think it would be death wobble. It requires an extreme and immediate reduction in speed to stop it in my experience in a CJ2A. I would x2 on the u-joints to start.

That is a good point. I just checked a couple of sources and found that the numbers matched from source to source and went with them. Neither was in graph form. Looks like 190@4500/225@2500 for the 4.0 and 140@3600/240@1600 giving the 318 the advantage in TQ lb-ft ( :Canadaflag: ) at low RPM but the HP edge to the 4.0 once moving....if you could get it moving.... :crossfingers:

They do indeed. Feel free to send me those drop brackets... :brows:

alright, any suggestions as to what brand and what style lift, weather it's long arm or somethin else, Redwolf After looking back over your posts I would probably look at lift of about 4.5" that includes rear leaf packs. Although it happens both ways I hear more people wishing they had gone higher and only spent for lift parts one time than I hear people saying they went too high. 4.5" is a very popular lift height with lots of positive feedback. Here is a good example of what I am talking about getting: http://www.rustysoffroad.com/jeep-suspension/jeep-suspension-lift-kits/mj-comanche-86-93-jeep-suspension-lift-kits/rustys-mj-comanche-4-5-spring-pack-kit.html

Ahhhh... Are you still using RC short arms & springs with the unusual and apparently successful set-up of using custom control arm drop brackets to increase your flex? Not exactly an apples to apples comparison there but it obviously works very well. Kudos. But one should not expect that flex with an RC or any kit of 3"-3.5" inches or so, should they? Maybe it is that the biggest difference between the RC stuff that I got in the kit and the RE stuff a pieced together is in the RE spring rates being accidentally better for my particular application. Either way if I can find the pics and get them scanned I can demonstrate the diffidence on an RTI ramp between my '91 RE and '88 RC where both front suspensions use the same exact factory geometry. The biggest difference between the two is the 1" spring height difference. And an oops: my fixed LCA's are Rusty's not RE as I got them NIB used for cheap as part of a package deal.

2.67 for straight regular here this morning

i will try to remember that.

I am at 5.5" in the front and I have zero bump steer issues with the factory pitman arm and a RE adjustable track bar.

That may well be. But with 45 more HP and only giving up 15 #/' (lb-ft-thanks gogmorgo) of tq it appears that the truck may be less of a dog with a 4.0/ AW4 4 speed auto then it was with the factory 318/727 3 speed auto as swapping in the jeep tranny makes more sense than trying to adapt the Mopar patterned 727.