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Axle Upgrade vs. Full Swap?

894 views 13 replies 6 participants last post by  Spetie 
#1 ·
So here’s the deal,

I’m absolutely a window shopper and like to plan things out, so while I can say eventually I’ll get to this, I’m not where close to doing this anytime soon.

The goal of my ZJ is to do some mild/difficult type of off roading but will need to reliably pull a decent sized camper across the states.

Edit: none of the below is going to make any sense due to large gaps in knowledge lol.


All that being said the upgrades on my dream list include a re-gearing, WJ break upgrade, and eventual locker.

So the question I’m posing is... am I better off doing all these upgrades to my perfectly fine D44.

If I keep my current D44 I’m going to need to purchase the following to upgrade. (Junkyard pickups)
-WJ knuckles $24x4
-WJ calipers $20x4
-everything else needed for the WJ brake system.
-16 in wheels $50-60x4
-locker

Estimating 800-1k

Or (and I have no idea what I’m talking about from here on out)

Would it be more economical to snag a full D44 Axle from yard that already has the full brake setup already for $240 and possibly get lucky enough to find one with a LSD?

And if we’re considering swapping full axles for $240 would I be better off getting the Ford8.8?

Edit: I also already have JK 17in rims so I would save myself the cost of wheels as well since the WJ bolt pattern is the 5x5
 
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#2 ·
I'm guessing you forgot to mention some things.. You're talking about keeping your current rear D44a, and if so you'd upgrade the front D30 with the WJ knuckles & brakes? If you're planning on upgrading a D30, you definitely want to do that to an XJ HP D30, not a ZJ/TJ LP D30
I'm also wondering why would you need four knuckles (only two needed for a front axle) and four calipers? You don't need to change anything in the rear axle if you're doing the WJ knuckle/ brake/ steering swap - you only change the required parts in the front.

What is your tire size and lift height, what are you planning on doing? For most people, HP D30 + D44a (or Ford 8.8) is good for 33" tires on a ZJ. Some people have had luck with up to 35s with a turdy; both the D44HD & Ford 8.8 with alloy shafts can handle up to 35s pretty well even with V8 power.
HP D30 starts to become an issue if you have a front locker & short gears (4.56 or 4.88), have a built V8, do harder trails and occasionally need to use heavy foot. That will be guaranteed axle carnage, at which point I very highly recommend going with a front D44 and skip the turdy.


Many of the 15" x 8" 4"BS steel wheels fit over the WJ brake calipers after you grind a bit from the calipers edges - there's plenty of material there so no need to worry about grinding a hole into them or making them too weak.
Alloy wheels need to be 16".
 
#4 ·
I'm guessing you forgot to mention some things.. You're talking about keeping your current rear D44a, and if so you'd upgrade the front D30 with the WJ knuckles & brakes? If you're planning on upgrading a D30, you definitely want to do that to an XJ HP D30, not a ZJ/TJ LP D30
I'm also wondering why would you need four knuckles (only two needed for a front axle) and four calipers? You don't need to change anything in the rear axle if you're doing the WJ knuckle/ brake/ steering swap - you only change the required parts in the front.

What is your tire size and lift height, what are you planning on doing? For most people, HP D30 + D44a (or Ford 8.8) is good for 33" tires on a ZJ. Some people have had luck with up to 35s with a turdy; both the D44HD & Ford 8.8 with alloy shafts can handle up to 35s pretty well even with V8 power.
HP D30 starts to become an issue if you have a front locker & short gears (4.56 or 4.88), have a built V8, do harder trails and occasionally need to use heavy foot. That will be guaranteed axle carnage, at which point I very highly recommend going with a front D44 and skip the turdy.

Many of the 15" x 8" 4"BS steel wheels fit over the WJ brake calipers after you grind a bit from the calipers edges - there's plenty of material there so no need to worry about grinding a hole into them or making them too weak.
Alloy wheels need to be 16".
Ah, see this is where my ignorance kicks in, I thought the WJ break upgrade was all the way around on both axles not just the front. Honestly I'm really surprised with the amount of reading/videos I've watched that I haven't seen this called out. Most of the time when I'm watching the videos they just do 1 side because it'd be redundant to even do the 2nd side of the axle. That clears up a lot tho and I see where the confusion would be when I'm talking about swapping out the rear axle to save money on a front end brake upgrade lol. Have I mentioned I'm still pretty new to all of this, because if I haven't I'm very new to all of this haha. I retain information pretty well so if it sounds like I know what I'm talking about take it with a grain of salt that it's very possible I'm missing something. (And it's usually the basic thing that people feel they don't need to mention about things lol)

All that being said I didn't realize you could shave the calipers down, which is great news because there is a nice set of Roadian AT Pro RA 8's at my junkyard with a lot of tread on them and their 31x10.5/15 which I believe will fit on to my stock ZJ rims. Although I have no experience with the brand I'm not sure I'm going to be able to swing the duratrac's any time soon.

Ultimately the lift will be around 2-2.25in and running no larger than 31's what I'm worried about is once I start off roading I'll get bit by the bug and want to keep getting into harder and harder things and if I can prevent buying the same thing twice I'd like too.
 
#3 ·
As far as I know, the rear disks on a ZJ and a WJ are pretty similar in size. The real upgrade comes from the WJ brake swap on the front D30 axle. The rear D44 on a WJ is not a direct swap onto a ZJ because the suspensions are completely different, the axles are different widths, and the bolt pattern is different (although you said you'd be swapping rims so that part is irrelevant). At that point, it'd be easier to do an 8.8 swap because you'll have to weld new brackets on either axle and the 8.8 is more widely supported than the D44a that is in the ZJ and WJ.

Timo knows quite a bit about the WJ brake swap as he's done it on his rig. FWIW, If I were in your position, I would fix up the front with the WJ brake upgrade, keep the ZJ D44a, and regear both axles under your current budget. I assume you're talking a lunchbox style locker for the D44a. The 8.8 axle is superior when it comes to aftermarket support for lockers, axle shafts, carriers and the like, but idk how big you're thinking on modifying this rig. Since you're regearing I assume it's for bigger tires+lift but I don't know how big. Tire size and lift would dictate the direction the most I think. A really solid combo is a D30 HP up front and 8.8 in rear but it seems overkill if you're only doing light off-roading. Overall it's how much you want to spend and where you see yourself going with it.
 
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#5 ·
As far as I know, the rear disks on a ZJ and a WJ are pretty similar in size. The real upgrade comes from the WJ brake swap on the front D30 axle. The rear D44 on a WJ is not a direct swap onto a ZJ because the suspensions are completely different, the axles are different widths, and the bolt pattern is different (although you said you'd be swapping rims so that part is irrelevant). At that point, it'd be easier to do an 8.8 swap because you'll have to weld new brackets on either axle and the 8.8 is more widely supported than the D44a that is in the ZJ and WJ.

Timo knows quite a bit about the WJ brake swap as he's done it on his rig. FWIW, If I were in your position, I would fix up the front with the WJ brake upgrade, keep the ZJ D44a, and regear both axles under your current budget. I assume you're talking a lunchbox style locker for the D44a. The 8.8 axle is superior when it comes to aftermarket support for lockers, axle shafts, carriers and the like, but idk how big you're thinking on modifying this rig. Since you're regearing I assume it's for bigger tires+lift but I don't know how big. Tire size and lift would dictate the direction the most I think. A really solid combo is a D30 HP up front and 8.8 in rear but it seems overkill if you're only doing light off-roading. Overall it's how much you want to spend and where you see yourself going with it.
Excellent! Thanks for the info after reading what you and Timo, replied to that all makes a lot more sense. Thanks for getting back to me on this. Ultimately the for now goal is to get up and running on 31's with a 2-2.5in lift.
 
#6 ·
As much as I love the WJ brake swap (I do!) and the associated steering upgrade (also great!), if you're just planning on 2" and 31s for now and don't plan to wheel hard... I wouldn't bother unless you plan to tow stuff. The WJ swap is a fair amount of work and expense, and while they're not the greatest the ZJ brakes are generally good enough for 31s. The inverted-Y steering isn't perfect either, but it does do a good job of keeping the tierod out of the rocks and again it's strong enough for 31s.

Personally, I'd say make sure your existing knuckle pad ears are fixed up (fill in the wear spots with weld, file flat) and install some good-quality pads. That's a low-cost option that makes the best of your existing hardware and you can always upgrade to WJ stuff later if you feel you need it.

Have a read through my brake install thread to get an idea of cost and level of effort.
 
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#8 ·
As much as I love the WJ brake swap (I do!) and the associated steering upgrade (also great!), if you're just planning on 2" and 31s for now and don't plan to wheel hard... I wouldn't bother unless you plan to tow stuff. The WJ swap is a fair amount of work and expense, and while they're not the greatest the ZJ brakes are generally good enough for 31s. The inverted-Y steering isn't perfect either, but it does do a good job of keeping the tierod out of the rocks and again it's strong enough for 31s.

Personally, I'd say make sure your existing knuckle pad ears are fixed up (fill in the wear spots with weld, file flat) and install some good-quality pads. That's a low-cost option that makes the best of your existing hardware and you can always upgrade to WJ stuff later if you feel you need it.
Yea, the end game will be towing a good sized camper from Southern Mo to AZ, WY, and a few other places during the summer. On the flip side of that we have a lot going on right now with the purchase of a house so the camper stuff I'd say we are a solid year or so out from jumping into. I got my Kolak lift kit in last week but haven't gotten the time to install yet (it's the worst coming home every night seeing all those boxes in the garage).
 
#7 ·
5.2 V8, 31s and stock gears will work just fine, buy high quality front rotors and pads and enjoy :thumbsup: I honestly would't worry about braking power, WJ steering and brakes are a big improvement but by no means necessary on 31s.

I would't have done the swap for 32s, but I had already bought all the parts for my XJ that was on 35s before I started a different kind of build on it. That being said, improvement in braking power and steering feel was a huge improvement over the stock setup.
 
#10 ·
Az has some great wheeling many thousands of miles. in fall through spring( not in the summer). best time to go through and catch events free or pay. Trails here are Az1.0-5.0. anything over 3.5 is getting rather rough even in a Wrangler with lockers on 33s.

If in the area of parker all the way to kingman, west AZ. we run trails during this time easy to hard. here is a local trail they filmed and the first 5 seconds is the best of it. trail is rated 3 but there is things that are much harder on the way 4.-5 ways. Here is a friend we call Fast Freddy doing what i know has only been done by few people to send that. Miller Fall Az4+/5. seen a lot of buggies back off it when the pull up and see it. anyway its just at the very start of this film took, he all most missed the shot. cool trail too. not to hard unless you go many of the "hard ways".

 
#11 ·
Az has some great wheeling, in fall through spring( not in the summer). best time to go through and catch events free or pay. Trails here are Az1.0-5.0. anything over 3.5 is getting rather rough even in a Wrangler with lockers on 33s.

If in the area of parker all the way to kingman, west AZ. we run trails during this time easy to hard. here is a local trail they filmed and the first 5 seconds is the best of it. trail is rated 3 but there is things that are much harder on the way 4.-5 ways. Here is a friend we call Fast Freddy doing what i know has only been done by few people to send that. Miller Fall Az4+/5. seen a lot of buggies back off it when the pull up and see it. anyway its just at the very start of this film took, he all most missed the shot. cool trail too. not to hard unless you go many of the "hard ways".

Oh man! Thanks for this I'll be saving this for sure. I'm glad you took the time to read through the asinine original post to see the conversation below lol. My bro just bought a house in Scottsdale and once their done building it we will have a place to stay when we head that direction. He's got a 2019 GC with all the fixin's but I doubt he will do much more than drive in the rain out there. Lol
 
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