Thread for GM 14 bolt conversion? Should I?

Ok I am getting ready to do the mods to a GM 14 bolt aquired from a friend. Would this be of any intrest to anyone for me to make a thread about it?
I am going to be choping it down to the same width as the D44, disc brake conversion, and all the measurements for the custom shafts that will be going in it and where I got all the parts necessary to do this, along with the cost once done.
The 14bolt comes from an military CUCV pick up.

Also what angles do I need to pay attention to? Sitting on 3" of lift but will be going to a 6" kift very soon.

Any thoughts on 4 link rear set up?

I like my 14bolt. I'm going to shave it when I do a 4-link. Depending on what you wheel you might get a pinion guard. Oh weld the tubes to the center as well.

What tire size?

Gotta be big, you know the clearance really sucks.

Sure, a thread on the topic would be useful.

The tire and wheel size in the end would be the General tires from a military hummer. I have a set of 5 wheels and tires I got from a military surplus when I was at 29 palms california. 37's with the 2 piece wheels. But those will not be going on till I am fully exo'd and have both front and rear 4 linked. Then I will be ready for some serious wheelin and it will be a trailer rig then. for now 35's, which I hope should be on by the time we head out for Moab this march.

jmop said:

I like my 14bolt. I'm going to shave it when I do a 4-link. Depending on what you wheel you might get a pinion guard. Oh weld the tubes to the center as well.

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Cool thanks for the info.

mk153smaw said:

The tire and wheel size in the end would be the General tires from a military hummer. I have a set of 5 wheels and tires I got from a military surplus when I was at 29 palms california. 37's with the 2 piece wheels. But those will not be going on till I am fully exo'd and have both front and rear 4 linked. Then I will be ready for some serious wheelin and it will be a trailer rig then. for now 35's, which I hope should be on by the time we head out for Moab this march.

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I wouldn't put in a 14 bolt for 37" tires. It just hangs too low, and you won't like it. If you do decide to use it, you must shave the bottom as much as possible. An unshaved 14 bolt with 35's or even 37's is a boat anchor, and if you intend to do the type of wheeling you'll want to do with a trailered rig, you'll want an axle with more clerance or you won't hang with the other guys you'll wheel with.

Shave, shave, shave..........or use something else. Trail performance is all about rear diff clearance, among other things. It can't be ignored.

I like what this guy did with leaves,



I think this is the route I'm gonna go, instead of a 4 link.

Those long shackles allow a lot of droop. Anyone know how they handle on the street? I'm guessing some scary moments in quick brake-checks.


I'd agree with the guy on running the 14 bolt with 35"s. You don't need that much axle with 35"s, and the ground clearance will be a bitch. I have a rear D60, which has a full inch in clearance over a Corp. 14 in my CJ, and used to hang it up frequently on 36" TSLs. Swapping a set of 38.5" SX's on cured that. I wouldn't bother with a Corp. 14 on anything less than 38"s.

I would not swap this axle in for <37" tires unless you are in the rocks and very aggressive. It is very big and heavy.

Lots of info here - 14b bible.

Do a shaved ford 9 inch.

lancey3 said:

Do a shaved ford 9 inch.

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Now that is an idea:yelclap:

ColoradoRaptor said:

Now that is an idea:yelclap:

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but that's not the question, he is doing the axle, the question is weather he should do a write up on the work he does to it in the process, my answer is yes, do the write up. but dont install it for less than 38's they are trail plows if you do.

Ive started to shave the bottom of my 14 bolt, cut it off with a Sawzall, now its at BMC getting a 1/2" plate welded on the bottom. Plasma'd out a diff ring, and will build off of that. I wont run anything less than 38" tire. Ill get about 1.5" gained clearence, which is like going from 37" tires to 39" tires, or so. If you go to much, you will have to get the ring gear shaved.

Get a pinion guard, or make one. GLOR sells them, as well as on Ebay.

Also get the U bolt style yoke from AA or High Angle Driveline.

Weld the tubes like previously said, they like to spin.

Also, for a narrower width, use DRW or C&C hubs on a SRW axle. It puts you at 63.5" WMS. I wouldn't worry about narrowing the tubes, just narrow the front instead, IMO.

Ditch the drums, and go discs. RuffStuff brackets, '78 3/4 ton front 4x4 rotors and calipers.(Cadillac calipers for the Ebrake). That will shave off alot of weight.

Another thing, they do make alloy shafts for it, which may be more overkill. Moser, Dutchman, CTM, ect... Yukon makes 5.38's for it, thats the gearset I got.

The carrier is huge on those, a Detroit locker actually goes inside of it. They do make an ARB for it, but spendy. Yukon makes a full spool, but also up there in price. I welded mine, which is alright on a big axle like this, IMO.

A few pics.

a 38" tire on stock width axles?

gregmondro said:

a 38" tire on stock width axles?

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True, I was going to question that as well, it does work (seen pictures of rigs with them) but there is a ton of cutting involved and most likely not street drivable without a ton of work.

That being said, I also considered the a FF 14B for my XJ, but I got a killer deal on a D60. Bored the spindles to except Dutchman 35splined alloy shafts (only 1541H, but still)... 5.38s, spool, and discs are in the plan as well... just need the money. Stock D60 width, but mine won't see any street time.

However, I'd have to agree with what Goatman has said, I think he's right on. Granted no personal experiance for the FF 14B, only D60s.

If you're planning on running <35s on the 14B... plan on staying on the street... the first M&M will hang you up. :shiver: :jester:
>37s and you'll start to be in the alright catagory, more if you shave it similar to CanMans setup. I'd also like to see a thread on this, I love seeing what others are spending money on when I ain't got none for my XJ!

RCman said:

True, I was going to question that as well, it does work (seen pictures of rigs with them) but there is a ton of cutting involved and most likely not street drivable without a ton of work.

That being said, I also considered the a FF 14B for my XJ, but I got a killer deal on a D60. Bored the spindles to except Dutchman 35splined alloy shafts (only 1541H, but still)... 5.38s, spool, and discs are in the plan as well... just need the money. Stock D60 width, but mine won't see any street time.

However, I'd have to agree with what Goatman has said, I think he's right on. Granted no personal experiance for the FF 14B, only D60s.

If you're planning on running <35s on the 14B... plan on staying on the street... the first M&M will hang you up. :shiver: :jester:
>37s and you'll start to be in the alright catagory, more if you shave it similar to CanMans setup. I'd also like to see a thread on this, I love seeing what others are spending money on when I ain't got none for my XJ!

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Thanks for the info. Actually it is an eye opener to be honest. At least most of the work I do not have to pay for, the guys I am useing have a lot of time on thier hands and all the tools with nothing to do. As long as you can reason some type of constructive training out of it, you can get anything acomplished in the military for free
Once finished the axel may sit uninstalled probably untill I can build the XJ up enough for it then. I wanted the build for a purpuse built trail/rock rig, which is a couple of years off for what I have now.
As for clearance... I have to smack myself on the head for that one! I totally didnt even check the clearance on that bad boy. I just thought of how many times I have driven CUCV's over so many diffrent types of obstacles, never getting stuck, and wanted that type of performance in my XJ. I do have to measure it though since the CUCV only had 31's or 33's on them (mostly 31's at our unit) to se how much there is exactly for future planning.

Besides, who wouldn't try something new with this stuff if they didnt have to pay for much of the work?! Getting it done just saves me time on the future when I will be ready for something like this in the XJ, Shoot I am just finishing up the motor and I built that up to 5.0L (it migh be a smudge more). Which, by the way, was not all that expensive... comparatively. Along with creating a tuned port intake for the monster. When engineers get bored crazy things happen

Yeah, I just measured it... only 6" of clearence available it if were installed right now with the 31's on it. I checked that number from measureing the set up I have now on the XJ at the center of the axle with the wheel and tire installed on my driveway. Then I put the big axle on some bricks until the center of the axle came to the same heighth as to my previous measurement, which was 14 1/2", then measured from the low point of the housing.
The clearence I have now is only 9", so I would be losing 3" and that would suck for now. I then measured my military hummer wheels and tires, the clearance would be 13" (I am accounting for 2" of tire sag once all the weight is on them)

Here is the Axle



Now for the measurements

So far, this thread seems like a great example of the principle that just because you've got something or can get something for free, doesn't mean it's a good idea to use it.

You do NOT want to narrow that axle. Using C&C hubs to get the narrower available width is the most you want to go. Anything less than that and you will be all over the inner fenderwells on your XJ and you'll either have no suspension travel or be a foot taller than you need to be. Especially if you plan on running the H1 wheels at stock backspacing.

Also, go back to your other thread and read my response there. There's no reason to put any money into fixing one of these axles unless you've already done work on it (welding brackets, trusses, etc). They are $100 at nearly any junkyard across the country. Mine was $600 with 0 miles on it, disc brake conversion installed with new rotors and calipers, 4.56 gears, Detroit locker, and perfect bearings/seals etc. If you add up everything you want to do to yours, even ignoring the labor, I would bet you would spend nearly that much in parts.

I shaved roughly 3/4" off the bottom of mine - the 'lazy shave' meaning I left the bottom bolt hole in place. With 39.5s I hit it a lot.

Also keep in mind that using that axle will require extensive bracing to the unibody if you want anything to hold up, and also you'll likely have to relocate the gas tank into the cab to clear the axle on uptravel (or see above regarding stupid amounts of lift).

As for the 37" military tires...you'll get what you paid for. You could definitely get away with running a stock D60 rear or an alloy'd D44 rear with those tires as you'll rarely get traction anyway.

edit: Here's how my axle turned out.

Ok, cool. I am glad I got to see how the set up looks lke. Biggest reason why I posted here first... Get all the knowlege first before moving

I had been poking around on the net and looked at Pirate4X4 for the write on on how to shave the 14 bolt, at best they only added 2 more inches to the clearence, and they still had to shave the ring 1/4"!

The gas tank is allready being planned for a fuel cell up inside the cab. I was doing that before I even looked at the axle for better departure angles and protection of the tank. Along with making room for a 4 link, kinda like what you have.