Front Axle Choices

[DaleII]

I've been researching the numerous choices in front axles swaps, and wanted to gather others inputs. The goal with this setup to to drive way too many miles. Hopefully at least 200k+ both on and off road across all types of terrain and back country.

My current long term build plans are:

• Diesel engine swap, looking for a good deal on an Isuzu 4BD1T with likely a 700R4 or 4L60e.
• Transfer case to be determined but might stick with upgrading my NP231J or if a NP241OR makes itself available for a reasonable price I'll buy that.
• I don't plan on going over a 35" tire size anytime in the future with this rig. I may entertain 37's one day but nothing more. This means lower gear options.
• Suspension will be modeled after the Savvy midarm kit. I would buy the kit, but want the experience of making one myself. I'll be studying up on suspension dynamics and probably trying to copy Blaine's dimensions. I also have my own lathe and tools to make a number of the components myself. Too bad they don't sell schematics!
• Selectable hubs on the front are mandatory. I might even convert to full floating in the rear with flanges.
• DIY highline fenders to help keep low center of gravity.
• DIY big brakes.
• Possible coil-overs if suspension needs warrant it.
• Keep a close to factory track width. I currently have aftermarket wheels with 31x10.50R15 tires that stick out slightly from my aftermarket fender flares. Being in Oregon we have four seasons and weather and I'm going to keep it street friendly. Stepping up to 12.50 width I might get a wheel with a larger backspace to keep the tires under the flares.

Now for the axle options. I have a LP Dana 44 in the rear. This will likely do everything I want it to. I will eventually install sleeves, truss, locker, and gears to suite. But for the front...

1. Build the HP 30 housing I have from an XJ non-disco model. I could purchase and utilize the REID 33/44 upgraded knuckles to achieve hubs and bigger breaks, but I don't have the option of anything lower than a 5.13 and the ring gear is smaller at 7.12". This would make an easy install initially but not so important with a future three link. I have no doubt with sleeves and a truss it'll be as strong as a I need.
2. Find an older ford HP 44 and narrow it to match the factory WMS-WMS of 60.5". If I found a '78-'79' HP 44 from an F250 it would have 3" tubes at 0.5" wall thickness. This would be plenty strong, have the gear options, brakes, and hubs, but these are increasingly hard to find and getting more expensive. I could still do the same with a F150 or full size Bronco or Jeep and achieve all the same. With narrowing, an axle with a cast wedge might even be viable. I could cut the wedge out and narrow at that location using a sleeve to keep everything straight?
3. Used Jeep Rubicon axles are still available, but I'm throwing away mostly everything but the housing to achieve my goals listed above. Doesn't seem worth it for the price they're going for.
4. JK axles are likely too wide. I've done some measuring and they would fit with the stock 7" backspacing wheels, but as soon as I go wider tires and wheels it'll push the tires outside of the flares. I might be able to make this work, but they are still cost prohibitive.
5. Aftermarket housing and add the outers from an older Ford/Chevy Dana 44 for the hubs and brakes. This option and any other variation of build and buy seem to be spending around $2,000 on just the housing even with buying a center and building everything else. Not to mention locker, gears, and axle shafts.

Does anyone have any thoughts on the above? Anything I missed? Is there any goal I should modify to make any axle more compatible? Is there any reason I shouldn't chop down a full size Ford axle and sleeve/truss it then add the locker and gears like I would have to do for any other option? If someone wants to toss me a reasonably priced Rubicon 44 front axle housing I'll be on my merry way.

Thanks for your time!
Dale

 

[jjvw]

My initial thought is that you need to settle hard on the tire size. Up to 35s and stock width will work. 35s and up will benefit from more width. These are two very different builds.

Get the concept of LCoG out of your thinking. With a tire size in mind, set a goal for suspension travel, both up and down, along with a belly height. Build to suit. The ride height and wheel clearances will be what it needs to be.

If you are going to copy the mid arm, then start understanding what purpose it serves. It isn't part of a LCoG build, whatever that term means to anyone.

 

[DaleII]

My initial thought is that you need to settle hard on the tire size. Up to 35s and stock width will work. 35s and up will benefit from more width. These are two very different builds.

Get the concept of LCoG out of your thinking. With a tire size in mind, set a goal for suspension travel, both up and down, along with a belly height. Build to suit. The ride height and wheel clearances will be what it needs to be.

If you are going to copy the mid arm, then start understanding what purpose it serves. It isn't part of a LCoG build, whatever that term means to anyone.

For the purpose of this thread 35” will be the max tire size. It’s the largest size that makes any sort of sense to drive long distance and still handle most off road obstacles.

Maybe LCoG is the wrong term. More applicable would be saying I have a 1.25” BL, plan on doing a custom front high like fenders, which equates to minimal lift being required to flex 35’s, to my knowledge. I routinely see 4” but I believe with the above listed I should be able to achieve an inche or two less.

I’ve seen the sort of build I want to do numerous times with almost this exact hardware. The equation lies in that they started with a Rubicon and I’m not. If I started with a Rubicon I wouldn’t be asking these questions. Starting with a Rubicon wasn’t an option over ten years ago. So here we are.

 

[jjvw]

Keep in mind that a stock TJ has about 4" of up travel. Even with highlines, if you want to maintain stock performance be prepared to chop up the body with your plan.

Anything other than short arms is unnecessary with an inch or two of lift.

 

[Chris]

I see no reason whatsoever to go with anything other than stock axles unless you're going bigger than 35s.

Fitting anything other than stock axles will be unnecessary, lots of extra work, and then you have to answer questions such as what about suspension? Will you do coilovers? If so, that's another huge can of worms.

If it was mine, I would stick with stock axles and just build them to suit.

This of course assumes you won't be going over 35", but as others have said, you need to make a 100% firm decision on what the max tire size is you plan to run, and build around that.

 

[DaleII]

I had the thought of using the HP 30 housing with the REID knuckles to achieve hubs and bigger brakes, but didn’t like the idea of potentially wasting the money on a locker and gears in case the ring gear suffers a failure. But as it turns out sourcing any other kind of 44 housing isn’t trivial.