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Unread 08-09-2010, 07:50 AM   #1
Faramir66103
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JK D44 rear axle in a TJ? talk me into/out of this

Hi Folks,

Our '99TJ is currently on a D35 rear with 3.73 gears running 33x12.5 BFG A/Ts. The new larger tires affected our power and gas mileage more than I expected and more than I'm willing to live with. My understanding is that the D35 isn't worth re-gearing. Also, as I understand it, the failure mode of the D35 ends up with the wheel sliding out of the tube and off the vehicle, where the D44 will keep the wheel on the axle and let me limp out on the front axle. I'd eventually like a rear, selectable locker, and disk brakes. So, I've been looking around for used D44s and found a JK axle somewhat near me. Here are the issues as I've been able to find them from various searches.

The spring perches, upper control arm brackets and track bar mount are in the wrong places though the lower control arm brackets are the same as the TJ. So new brackets will need to be welded on. What's this going to run me?

The JK axle uses a flange, not a yoke to connect to the drive shaft. I'm guessing there is an adapter of some kind that can be used to make this happen, or maybe a new rear drive shaft will be necessary. Any idea what this will cost?

The JK axle is 5 inches wider than the TJ. One could leave it that width or cut it down. If it's cut down, new axle shafts will be necessary, correct? What's a ballpark figure on new shafts?

The JK bolt pattern is different than the TJ. One could use spacers/adapters or have the rotor drilled for the new pattern. What else would need to be done to convert the bolt pattern so as to not use spacers/adapters? What would this cost me?

What else have I missed?

I know the Ford 8.8 is an option, and I'm researching that in parallel, but for some (most likely unreasonable reason) I'd really like to stick with Jeep parts. Is this nuts?

Before I make a decision I'm going to regret, I'd really appreciate some cooler heads to help me think this through.


Thanks,
Adam

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Unread 08-09-2010, 07:57 AM   #2
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How much fab work do you want to do?

I'd look for a TJ Rubicon D44. It's got what you want and it bolts in.

And yes, it's nuts to not use a part because it's not a "Jeep" part. The only thing that does is limit your options.
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Unread 08-09-2010, 08:09 AM   #3
97tjeff
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The JK D44 is extremely stout - I have a buddy on 37's that's not nice to his at all, and it just asks for more. As far as prices go for shafts, There are several companies out there that will build custom shafts for you, it all depends on what your budget is.

As far as the Flange driveshaft goes, I know that Rubicon Express makes a flange style driveshaft adapter.

I also know several folks running 8.8s, and there are good reasons for going that route too - there are plenty of aftermarket parts, you can find them with disc brakes, and they are TJ width, so you just cut off the brackets, weld new ones on, and you're ready to go.

It all depends on your budget and your know-how.
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Unread 08-10-2010, 08:13 AM   #4
Faramir66103
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Well, I decided to pass on the JK D44. I don't have the welding skills (though I want to learn), space, or equipment to do the work of converting the JK brackets myself, and to have someone else do it for me just pushed this axle out of contention. I'll keep an eye out for a TJ D44, and just be patient. Bolt up work I can do myself and really enjoy doing. I'm still looking at the 8.8 option, but there's a lot of info to absorb.

Thanks,
Adam
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Unread 08-10-2010, 08:54 AM   #5
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Quote:
Originally Posted by Faramir66103 View Post
Hi Folks,

Our '99TJ is currently on a D35 rear with 3.73 gears running 33x12.5 BFG A/Ts. The new larger tires affected our power and gas mileage more than I expected and more than I'm willing to live with. My understanding is that the D35 isn't worth re-gearing. Also, as I understand it, the failure mode of the D35 ends up with the wheel sliding out of the tube and off the vehicle, where the D44 will keep the wheel on the axle and let me limp out on the front axle. I'd eventually like a rear, selectable locker, and disk brakes. So, I've been looking around for used D44s and found a JK axle somewhat near me. Here are the issues as I've been able to find them from various searches.

What type of wheeling do you do and what percentage of the activity with the Jeep does that constitute?

If you had never succumbed to the Internet's BS about the 35, you would have no qualms about installing any of the various products out there that will take care of most if not all of your issues.

The first myth is that the 35 isn't worth re-gearing. That's pure BS.

Quote:
The spring perches, upper control arm brackets and track bar mount are in the wrong places though the lower control arm brackets are the same as the TJ. So new brackets will need to be welded on. What's this going to run me?

The JK axle uses a flange, not a yoke to connect to the drive shaft. I'm guessing there is an adapter of some kind that can be used to make this happen, or maybe a new rear drive shaft will be necessary. Any idea what this will cost?

The JK axle is 5 inches wider than the TJ. One could leave it that width or cut it down. If it's cut down, new axle shafts will be necessary, correct? What's a ballpark figure on new shafts?

The JK bolt pattern is different than the TJ. One could use spacers/adapters or have the rotor drilled for the new pattern. What else would need to be done to convert the bolt pattern so as to not use spacers/adapters? What would this cost me?

What else have I missed?

I know the Ford 8.8 is an option, and I'm researching that in parallel, but for some (most likely unreasonable reason) I'd really like to stick with Jeep parts. Is this nuts?

Before I make a decision I'm going to regret, I'd really appreciate some cooler heads to help me think this through.


Thanks,
Adam
Adam, I don't believe that the JK rear is 5" wider. I believe the track width is 5" wider, but I'll check today for you and find out in case you find another one you're looking at.
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Unread 08-10-2010, 01:59 PM   #6
Faramir66103
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mrblaine,

Thanks for the info. My TJ is a daily driver and for 9ish months out of the year, I work 6+ days a week, so it doesn't see much in the way of offroad driving. During the summer, I try to take it trail riding a couple of times a month and do one or two larger trips to Colorado, the continental divide, etc. to do more difficult stuff. I recently completed a trip west of Colorado Springs wheeling around the Collegiates, Tincup Pass, St. Elmos etc. with my three soon to be teenage nephews. This trip is becoming an annual rite with us and I'd like to be able to tackle more difficult trails. My concern is mostly with what happens in a failure. Due to my own nature and the nature of my schedule, I often wheel alone, or at least without another 4x4. I know this is considered a major no no, and don't want to start a discussion on this. I'd love to spend less and know I'll be ok even in the event of an axle shaft break. If you could explain, or point me to a decent explanation of how to accomplish the upgrades of my D35 without spending as much or more than I will on a used D44, I'd really appreciate it.

Thanks,
Adam
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Unread 08-10-2010, 02:17 PM   #7
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Faramir66103,

i stumbled upon these 8.8s not too long ago on the forum if you interested

Jeep Forum: Bolt In Tj Ford 8.8 Axle Asemblies

ECGS website
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Unread 08-10-2010, 02:28 PM   #8
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Ford 8.8 is also gong to require all new brackets that must be welded on, so if you can't do the work some one else will, but the track width is the nearly the same, and the bolt pattern is the same, so that's the bonus. I think if you want bolt in a TJ D44 is what you want. Another thing you may want to look at is a C-clip eliminator kit for your D35, this would eliminate the axle walking out if the shaft did brake, plus the kits come with upgraded shafts. A D35 is a decent axle and allows a lot of ground clearance, when compared to even a D44. If you never plan to go bigger than 35s a D35 with the proper upgrades is a good choice. C-clip eliminator kits run around $500 if I remember right, you don't get a locker, but it will make the axle much stronger.
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Unread 08-10-2010, 02:37 PM   #9
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It may not be a bad idea to keep an eye out for a set of axles that someone has taken out in order to upgrade. When looking for axles I kept my eye out for a D44 front/D44 rear, D44 rear/D30 front, or a good deal on an 8.8 with or without a suitable front.

I finally came across a D44 and D30 already regeared with 4.88s for under $1000. This is not ideal for everyone but it allowed it to fit into the build and budget. This may be a solution for you considering the Jeep is for the most part primarily a DD. You still could add lockers, upgrade the shafts, etc. as the build progresses or you needs/wants change. Regearing alone will probably cost big bucks!

Seems to me that this route may be more suitable for you. In the long run, you will have to choose on what best suits your needs/wants/preferences. As to what that may be, that's why we are here to help guide you along in the right direction and give you some options to choose from.

Keep an eye on this forum as well as others, especially local forums if they are available.

Here a couple I have handy:
www.novajeepers.com
rubicon owners forum . com (just put it together without the spaces. For some reason, JF was being weird and it would appear ************.com. Do not know why though.)


Hope this helps.
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Unread 08-10-2010, 02:51 PM   #10
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Quote:
Originally Posted by Faramir66103 View Post
mrblaine,

Thanks for the info. My TJ is a daily driver and for 9ish months out of the year, I work 6+ days a week, so it doesn't see much in the way of offroad driving. During the summer, I try to take it trail riding a couple of times a month and do one or two larger trips to Colorado, the continental divide, etc. to do more difficult stuff. I recently completed a trip west of Colorado Springs wheeling around the Collegiates, Tincup Pass, St. Elmos etc. with my three soon to be teenage nephews. This trip is becoming an annual rite with us and I'd like to be able to tackle more difficult trails. My concern is mostly with what happens in a failure. Due to my own nature and the nature of my schedule, I often wheel alone, or at least without another 4x4. I know this is considered a major no no, and don't want to start a discussion on this. I'd love to spend less and know I'll be ok even in the event of an axle shaft break. If you could explain, or point me to a decent explanation of how to accomplish the upgrades of my D35 without spending as much or more than I will on a used D44, I'd really appreciate it.

Thanks,
Adam
What locker or will you need a locker? If you are stepping up to harder trails, you should have it locked.
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Unread 08-10-2010, 06:35 PM   #11
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For what you are doing, I think Id just super 35 what you have with an arb and do the regear. I can't see spending the money on any jeep to regear and not add a switched locker - unless you only drive on the pavement.

When I was first starting out, I bought a set of 4.10 4cyl TJ axles instead of regearing. I got them for like $400. I ran 32's. Before I read all the internet hype about the d35 (and didn't know any better) I even ran a powertrax no slip locker in it. I never did break it. Then I started doing harder trails and some of my buddies were busting their locked d35 on 33's and 35's. So, when I went to 33's I super 35'd it. Never did bust it.
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Unread 08-11-2010, 08:22 AM   #12
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Coop, thanks for the advice and kind words. I've decided to be patient (man that's hard) and continue to research. If I find a D44 that fits my needs, is close enough to be practical and is a decent price, I'll probably go that route. I'm also reading more about the D35 upgrades, which are impressing me the more I read about them. I'll keep my eyes on those forums you posted and see what I can find on local forums. I've been watching Craigslist in both this area and around my families areas for good finds.

mrblaine, I absolutely would like a selectable locker, and like the mechanical simplicity of the Ox locker. The fact that the Super 35 kits come with a locker and upgraded shafts for roughly the same price as a used D44 are major advantages in my book.

Will the Super 35 kit and selectable locker work with a C-Clip Eliminator? Could someone point me to an explanation of how the C-Clip Eliminator kits work or explain it here?

I also ought to mention that on my bigger trips I pull a modified military M416 trailer with all the equipment, tools, food, water and other supplies. It doesn't do the harder trails, but it does go up the moderate trails to the campsites.

Also, I don't see this Jeep going to larger than 33" tires for many, many years. If, someday, it becomes a trail only rig, then all bets are off.

Thanks Folks,
Adam
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Unread 08-11-2010, 09:46 AM   #13
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You can get the c-clip eliminator and the super 35kit together. because you do not plan on going larger than 33s for some time i would just do that, you could also put some superior chromo shafts up front for a little extra insurance.
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Unread 08-11-2010, 01:28 PM   #14
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Ok, probably exposing my ignorance here, but . . . Would a C-Clip Eliminator added to a given locker be the same as the Super 35 with that same locker so far as axle strength goes? What I'm thinking is the Superior C-Clip Eliminator with an Ox Locker. It seems that this combination is only about $200 more than a Super 35 with the same locker and c-clip axles.

Thanks,
Adam
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Unread 08-11-2010, 02:38 PM   #15
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Originally Posted by Faramir66103 View Post
Ok, probably exposing my ignorance here, but . . . Would a C-Clip Eliminator added to a given locker be the same as the Super 35 with that same locker so far as axle strength goes? What I'm thinking is the Superior C-Clip Eliminator with an Ox Locker. It seems that this combination is only about $200 more than a Super 35 with the same locker and c-clip axles.

Thanks,
Adam
check the spline counts, if you are wanting a super35 cclip eliminator you will have 30spline shafts and locker. if it is just a regular cclip eliminator kit it will have 27 spline shafts and locker.
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