Comanche build questions

[Tomx31]

Hey guys,

So I recently got my first Comanche! I first laid eyes on this beautifully beat Comanche when I was 15 and ever since then I wanted my own. I finally found one and being stationed in south Dakota (Air Force)I have plenty of time to work on her. But being my first project truck I lack some of the knowledge so I turned to the experts. Now my daily is a lifted xj so I'm not completely in the dark. Anyway I have a couple of questions for planing phase.

1) I want to do an axle swap to Dana 44s, I was going to pull the rear from a fsj at the local jy. Do I need to get a SOA kit or can I just replace the leaf spring? Would a xj spring work?

2) How much work would it be to get the front dana44 to work on my mj?

I'll have a lot more questions so expect more. Thanks for all your help in advance guys.

[Megadan]

1. MJ Leaf springs are specific to the MJ, XJ springs are too short.  You can simply purchase leaf spring mounting brackets/pads and weld them to the new axle.  Do not use the factory XJ mounts as they are actually a little too narrow for the MJ.

2.  A lot, unless you spend lots of money to have someone else do it.
 

[daking]

I was wondering about a Dana 44 also. So there are no direct swap ones out there?

 

Anyone sell weld on brackets ? If so, then what other truck has a 44 that is ~ same width?

[Pete M]

What is the end plan for this truck?  tire size?  offroading style?  I ask because a dana 30 can be built pretty darn tough.  plenty of guys running them. :thumbsup:

[Marine1Texas]

unless your thinking of weight and some hard banks 30 would be just fine. I know you can do some custom brackets for cheap on the 44. Comanche 44 has different springs and the with is wider too. I have the metric ton and the leaf springs are wider even then my Comanche with regular 1/2 ton springs.

 

If you weld them on there make sure you do a good job, seen people weld them and crack after 10 or 15 trips crawing up rocks.

[Incommando]

Don't get hung up on internet scuttle butt about having to have D44's. That is mostly BS and shows that whoever told you that doesn't really know what they are talking about. 

 

There are no direct bolt in 44's except for a rear MJ unit that is #1 IMHO way over priced & #2 about the weakest Dana 44 rear made in decades due to tube weakness and being undersized. Even the also rare and IMHO overpriced XJ rear requires the same mods as a FSJ axle, or any other axle,  to fit in: New spring perches and a provision for shock attachment as well as a possibility for drive shaft length mods. 

 

If you have a D35 rear it is admittedly a weak unit for off-road use, If you are actually going to go off-road then the cheapest & easiest swap is a later 29-spline 8.25 from under an XJ. Plentiful, inexpensive, and easy to match your current gear ratios. It is in the ball bark of D44 strength ( probably stronger than an MJ/XJ D44) and is both the correct width and bolt pattern. Another common upgrade is a mid-90's Explorer 8.8 with disc brakes. Very strong and you can match 2 of the 3 common MJ gear ratios but it is  more expensive than an 8.25. It requires adapters though as it is narrower than MJ axles.

 

The front HP D30 is much stronger than a low pinion D30 in some ways. The later ones with 297 u-joints are arguably as strong as a TJ Rubicon D44 front due to the Rubi axle having a low pinion and being mostly D30 stuff. If you swap in big-joint front shafts and truss a HP D30 it is pretty darn stout for a light vehicle.

 

Unless you get a matched set of axles to swap in you will have other issues such as axle width front to rear, bolt pattern, gear ratio, and many little things. Swapping gears if you cannot do it yourself will be about $500 per axle. 

 

Adapting the factory front MJ suspension to any donor axle other then from another MJ/TJ/or XJ is pretty involved in both time and expense. The other option which is equally labor intensive is changing the front suspension to leaf springs to match the axle. Just the way this post is worded leads me to believe that you have a lot more research to do before making what is ultimately your and yours alone decision. 

 

Why would you want to change leaf springs? The MJ rear leafs are very flexy. Leaf springs do not much care what axle you put on them and the smart thing is to adapt the axle to the position of the existing springs. That question leads me to think that you may be too inexperienced to easily accomplish the kind of swap that you are talking about.

 

Around here you can buy an 8.25 and get new perches for about $100. Nothing else will come close to meeting that price unless you find an amazing deal. Getting big shaft front axle shafts for your HP D30 ( either used from a later XJ or TJ or new stock pieces if you don't want the expense of aftermarket shafts ) and then trussing it will be good on an MJ for the vast majority of users including those who keep tire size to 33" or so, do moderate or harder wheeling,  and know how to drive. You don't list your year or anything else about your MJ. If it has CAD then you will need to block that off to use the better shafts. No loss as it is unneeded and failure prone anyway.

 

I paid $75 for a used 29-spline XJ 8.25. I had about $35 bucks in spring perches & shock tabs, and then was able to weld it at home. I added an Aussie locker for $240. For less than $400 I have a decent rear axle that is locked. For my front HP D30  I bought new spicer shafts ( all 4 pieces) with the new stronger 760 u-joints for about $300. I use 32" mud terrains.  I have not trussed it yet but I take my MJ off-road at least a couple of times a month and don't shy away from much unless my tire size limits it. I have yet to break anything in the drivetrain and I am fairly aggressive with the gas pedal. It is not an unbreakable combo but it is a decent combo for me and, honestly, 95% of the other MJ owners here. 

 

You need to be brutally honest about how you will use your MJ to make a decision on the best way to go. You may want a hardcore wheeler but if in reality it spends 95% on the street than build it for how it will be used. 

[Incommando]

unless your thinking of weight and some hard banks 30 would be just fine. I know you can do some custom brackets for cheap on the 44. Comanche 44 has different springs and the with is wider too. I have the metric ton and the leaf springs are wider even then my Comanche with regular 1/2 ton springs.

 

If you weld them on there make sure you do a good job, seen people weld them and crack after 10 or 15 trips crawing up rocks.

Not so much. The metric ton springs are the same width as any other MJ springs. The factory D44 is also the same width with the same width perches as the D35. All MJ rear springs are 100% interchangeable. If your spring perches are in a different place or are for a wider leaf spring then  the leaf attachments on the frame would have to be different, as well, yes? And that is not the case. Metric ton spring trucks  did not have rear frame attachment differences,  If the frame mounts are the same ( and they are) you cannot put a wider leaf spring in it, either. If you have "metric ton springs" for an MJ that are wider you must have had to change your spring perches and cut-off both front and rear frame mounts to replace them with ones that will have to be wider to accommodate the wider spring. Did you do that? Because the factory didn't for metric ton springs. 

[daking]

Lots of good info here. 

 

I've been holding off on doing any major work to my front 30. Debating on swapping in a 44. 

 

From what I've read here, I'll stick with the 30.

 

Thanks

[HOrnbrod]

 

unless your thinking of weight and some hard banks 30 would be just fine. I know you can do some custom brackets for cheap on the 44. Comanche 44 has different springs and the with is wider too. I have the metric ton and the leaf springs are wider even then my Comanche with regular 1/2 ton springs.

 

If you weld them on there make sure you do a good job, seen people weld them and crack after 10 or 15 trips crawing up rocks.

Not so much. The metric ton springs are the same width as any other MJ springs. The factory D44 is also the same width with the same width perches as the D35. All MJ rear springs are 100% interchangeable. If your spring perches are in a different place or are for a wider leaf spring then  the leaf attachments on the frame would have to be different, as well, yes? And that is not the case. Metric ton spring trucks  did not have rear frame attachment differences,  If the frame mounts are the same ( and they are) you cannot put a wider leaf spring in it, either. If you have "metric ton springs" for an MJ that are wider you must have had to change your spring perches and cut-off both front and rear frame mounts to replace them with ones that will have to be wider to accommodate the wider spring. Did you do that? Because the factory didn't for metric ton springs. 

 

 

^^^ Maybe Kudo is confusing "wider" with "thicker", i.e. the 5-leaf MT springs vs. the 4-leaf standard springs.   :dunno:  

[Marine1Texas]

my 1987 metric ton package has different setup then my 1990 regular 1/2 ton. both are 4x4 both have leaf springs.

I measure metric ton springs at 77 mm wide not tall. The 1/2 ton leaf is measured at 65 mm. Now I know my metric ton 1987 has never been moded and came right from dealer

[Incommando]

All MJ rear springs are 2.5 inches. 3" wide springs as you claim would require different spring perches, shackles, hangers, and probably u-bolts & spring plates. It did not happen from the factory. Far too many people have swapped springs without such modifications and there would be different factory parts required. If you are correct then you may have hit the nail on the head: it came from the *dealer* that way.... But not the factory.

[Marine1Texas]

I still don't see much of a problem tho if you do a d44. I say stay with what you have the D30 and just reinforce it. it is not that expensive or hard to reinforce it.

 

My harvester we bumped up all support on the rear axle and front too. We welded 1/2 inch steel L arms along the upper axle on all 4 sides. That way we could load up to 2 tons on the back of it with out any issues. Some times we have to move 2 ton machines from the back shop to the front shop. it works great and have not broke a axle yet in 30 years.

[Incommando]

my 1987 metric ton package has different setup then my 1990 regular 1/2 ton. both are 4x4 both have leaf springs.

I measure metric ton springs at 77 mm wide not tall. The 1/2 ton leaf is measured at 65 mm. Now I know my metric ton 1987 has never been moded and came right from dealer

 

Perhaps you are confused as to which vehicle is the Comanche. The top picture that you show is a passenger side drop front axle with leaf springs. Are you claiming that is a factory Comanche set-up as well? As it is also closed knuckle it is a very old axle. Are you sure that you are know which vehicle to measure/post pictures of?

[Incommando]

Also as the previous owner of several multi-carbed vehicles of three different makes I would still love to see that dual six-pack ( 6 2-v?) set-up. Perhaps you could start a thread in The Pub while you are snapping pics?

[Tomx31]

Hey guys thanks for all the feed back! And your are right I have a lot of research to do beforeI start. On base there is an auto hobby shop with all the tools you can dream of including lifts. Also the guy who runs it is an experienced mechanic who helps offer know how and tips on projects I also have a bunch of more experienced jeep wise friends who are helping me. Anywa the truck is a 1988 pinoeer short box with a 4 speed auto on the column with a 4.0. My ultimate goal for this truck is lack of a better term be able to go anywhere. So I know its not necessary to do axle swap but I want the increased strength as well as just having rebuild axles. So my end game is being able to run 35' tires with lockers and not snap/break my axles.

[Marine1Texas]

Both trucks have coils in the front

[Megadan]

Hey guys thanks for all the feed back! And your are right I have a lot of research to do beforeI start. On base there is an auto hobby shop with all the tools you can dream of including lifts. Also the guy who runs it is an experienced mechanic who helps offer know how and tips on projects I also have a bunch of more experienced jeep wise friends who are helping me. Anywa the truck is a 1988 pinoeer short box with a 4 speed auto on the column with a 4.0. My ultimate goal for this truck is lack of a better term be able to go anywhere. So I know its not necessary to do axle swap but I want the increased strength as well as just having rebuild axles. So my end game is being able to run 35' tires with lockers and not snap/break my axles.

I've seen people snap Dana 60 axles.

 

You can run 35's on a Dana 30 with reinforcement, but it would be advised to be gentle.  Weld in or press in inner sleeves, or sleeve the outside of the tubes, Brace the C's, and maybe even do an axle truss.

 

Or, if you are made of money, you can do something like these.

http://www.summitracing.com/parts/gta-d44tj-fox488?seid=srese1&gclid=CNunzqqYsMUCFZeDaQodlRgAHQ

[Incommando]

Hey guys thanks for all the feed back! And your are right I have a lot of research to do beforeI start. On base there is an auto hobby shop with all the tools you can dream of including lifts. Also the guy who runs it is an experienced mechanic who helps offer know how and tips on projects I also have a bunch of more experienced jeep wise friends who are helping me. Anywa the truck is a 1988 pinoeer short box with a 4 speed auto on the column with a 4.0. My ultimate goal for this truck is lack of a better term be able to go anywhere. So I know its not necessary to do axle swap but I want the increased strength as well as just having rebuild axles. So my end game is being able to run 35' tires with lockers and not snap/break my axles.

A low-pinion D44 front like what is found in a FSJ really does not give you that much over most high-pinion D30's. If you want to go with a stronger axle without paying $5K to an aftermarket company then you are probably looking at full-width axles. An older  Ford F250 HIGH pinion D44 front and matching D60 rear is a nice set-up. It gives you both a stronger high pinion front  center section and thick axle tubes...but still the same size u-joints as a later D30. Pairs like this are getting harder to found and more expensive, though. Almost any axle can be adapted through the use of pre-made kits from numerous sources like Ruff Stuff. All of this is doable it is just time consuming and can get pricey. 

[Incommando]

 

Both trucks have coils in the front

Yes but you are apparently trying to pass off a pic of a 3" leaf-sprung front axle of another truck as the leaf-spring rear axle on a Comanche. Again, the top picture is not of a Comanche. A more suspicious person would believe that you went out to photograph what you "knew" to be correct about spring widths, found out you were wrong, and then photographed a tight picture of a vehicle with 3" springs hoping to pass it off as the rear of a Comanche and also hoping that no one noticed. I of course am not that suspicious. But a picture of a tape measure across both sets of springs that also shows they are clearly under the rear of a Comanche would help clear up whether or not you have 3" wide springs. It would not clear up their origin if you did have them, though. 

[Tomx31]

So truss the dana30 and basically rebuild it and re gear and run either a fsj dana44 in the rear or a ford 8.8? This also brings me to my next series of questions. As for the lift. I have done a lift on my daily so I'm not that in the dark about this. I want to gather your opinions on the spring over axle lift for the rear. Likes/dislikes? Pros/cons? Alternate lift methods? Also do I need to do a SOA if I'm swapping in a rear from a fsj or the ford 8.8 or can I just get aftermarket leaf packs and possibly shackles? I'm not a fan of add a leaf set ups

[dunnc1991]

Between a FSJ rear 44 or an 8.8, I'd go 8.8 even just for the simple reasons of same bolt pattern and disc brakes. As far as lift, if you're planning on running 35" tires, you'll need a SOA rear, or your going to have to cut A LOT of sheet metal.

[Pete M]

later this year I'll be installing Mopar JK wrangler Rubicon dana 44 axles under a cherokee (for my uncle).  the axles will be around 4400 for the pair, but they are all brand spankin' new parts and have 4.10 gears, disk brakes, and push-button selectable lockers front and rear.  they are a couple inches wider than stock axles so you can run stock JK rims that are all over craiglist for cheap.  TNT makes a truss for the front that contains all the needed brackets already lined up for installation in an MJ/XJ.  just need to cut off the stock stuff and weld on the truss.

[Incommando]

If you want a lift and are swapping in a rear axle IMHO the SOA makes sense. Factory MJ springs are very flexy and should be retained if possible. You have to weld on rear spring perches and shock mounts whether you go SOA or not. This saves the expense of any sort of new springs and you will just have $100 or so in the same parts you would need to stay SUA. On the front you will probably need at least 5.5" of lift and may need to go higher or trim. I stayed with adjustable short arms at 5.5 but long arms or control arm drop brackets would be a good idea. Adjustable track bar with heavy duty body side mount is a must. You can get a truss set for as little as $40 from rusty's or you can spend over $300. Make sure you brace or upgrade your axle side lower control arm mounts and pass. side upper control arm mount.

[Incommando]

later this year I'll be installing Mopar JK wrangler Rubicon dana 44 axles under a cherokee (for my uncle). the axles will be around 4400 for the pair, but they are all brand spankin' new parts and have 4.10 gears, disk brakes, and push-button selectable lockers front and rear. they are a couple inches wider than stock axles so you can run stock JK rims that are all over craiglist for cheap. TNT makes a truss for the front that contains all the needed brackets already lined up for installation in an MJ/XJ. just need to cut off the stock stuff and weld on the truss.

The J/k axles are good ones and should be great under something as light as an XJ or MJ. The JK rear D44 may be the strongest D44 to date. But they have yet to drop much in price :(

[Megadan]

From what I have read/heard the front JK D44 isn't actually much stronger than a Dana 30 front.  The housing is thinner, and they have some of the same tube issues as the 30.  I'm sure it is a bit stronger, but is it stronger than a well built D30?  From the opinions I have seen, not really.