[andyknight3]

Hi all,

I'm looking to start collecting parts to put together an axle swap and was hoping for some advice on the best path forward. The goal is to eventually run 35s. I know this stuff has been covered but every jeep/jeeper's situation is a little different and I have a few specific questions.

I currently have the stock narrow track D30 and AMC20 (upgraded to 1 piece shafts). I'm running 31x10.5s on stock wheels and 1.25 (2.5 of total width added per axle) spydertrax wheel spacers at each corner to keep the tires off the leaf springs at full lock. I don't mind continuing to run wheel spacers in the future if need be. Based on how the 31s sit there's no way I would be able to fit 35s without giving up turning radius and constantly having the tire into the springs/frame when flexed.

Between the width issues and 35s pushing the limits of the D30 I'm mostly looking at D44 swaps from FSJs. I already have a D44 from an 86' CJ7 lying around for the rear (54.5 wms). For simplicity and cost reasons I would like to use it if I can but could always sell it and source something else if needed. I can get a wagoneer front axle, cut it down to CJish width (I believe it comes out to roughly 57.25") which would probably best match the width of CJ7 D44 I already have but I am concerned that it won't give me enough tire to spring clearance for 35s. I could also outboard the springs and run the wagoneer axle as is (about 60") although that doesn't help with tire to spring clearance at all just may be a little easier to do and gives a little extra track width. The other option I've been looking at is cut down a Wide Track FSJ D44 from a J truck to bolt to the CJ (I believe it comes out to about 61") which would give more clearance for 35s as there is a greater distance between wms and spring but would leave my front axle 6 1/2 inches wider then the rear (4 inches wider w/ spacers in the rear). Are there any issues with width differences that large? I'd rather not outboard the springs and run a Wide Track FSJ axle at full width as I'd rather not go quite that wide and would then definitely need to source a new rear axle.

Basically boils down to 3 questions:

1: Will 35s clear the front leaf springs at full lock if I run a wagoneer axle or do I have to run a WT FSJ axle?

2: What is the max width difference I can get away with between my front and rear axle? Obviously having a front axle slightly wider is normal and even desirable but how much wider can it be without causing any problems?

2: Should I keep the CJ7 D44 I already have or am I better off sourcing a different rear axle?

Thanks so much for all the help and advice, it is greatly appreciated.

 

[Hurricane4]

My ‘79 CJ5 has 31X10.50 BFG ATs on OEM 15X8 white spoke wheels. No wheel spacers - no lift. Stock suspension. Stock narrow track D30 & AMC 20. My front tires do not rub the leaf springs at full lock. What is the backspacing on your wheels? Should be around 3.50 to 3.75 inches.

 

[andyknight3]

Not sure on the exact backspacing but I can check. They’re the stock steelies that’s came on the jeep (as far as I know). They are not the wagon spoke type wheels. When I first put the 31x10.5 they rubbed on the springs pretty bad whenever I took at sharp turn or pulled tight into a parking space. Could just be the way the steering stops were adjusted by the PO. Either way I opted for spacers instead of adjusting the steering stops as to not lose any turning radius.

I also meant to mention that I’m running YJ 2.5” lift springs up front which are slightly wider than stock CJ springs although the tires rubbed on the stock springs before I made the switch. I went to the YJ springs and the wheel spacers at the same time and have had no issues at all since.

 

[Hurricane4]

OK - The stock steel wheels were either 15X5.5 or 15X6. That’s a large tire to mount on that narrow of a wheel. A wider wheel will “push” the tire outward.

 

[andyknight3]

Just popped off the spare and measured the backspacing - looks like 3 1/2 inches (give or take a smidge for measuring error).

In my head the wheel was a 15x7 but I think I probably just read that somewhere.

I know that a bigger wheel will move the tire out some and probably explains why I was rubbing with 31s I doubt it’d move it out enough for 35s, but let me know if I’m wrong!

 

[Axhammer]

The FSJ Dana 44 @ 57” WMS is a good option in my opinion for the front to handle 35’s. As far as the 35’s rubbing the springs or frame? I can’t answer that, but I would think it wouldn’t be much worse or different than 33’s on a WT 30/AMC 20/Dana 44 setup.

A Ford 8.8 from an explorer can be cut to about 57” WMS width easily. Buy some new aftermarket axles with 5 on 5.5 pattern and you would have a good matching rear end for 35’s. I know you can get 411 gears for the 8.8.

I’m not sure what gear ratios are available in the two axles, or what ration you plan on running? You could do a little research and find out pretty easy.

Pictured below is a 8.8 housing I narrowed to 57” for my CJ-7. It’s still in progress, but it’s not hard to do if you have a welder and basic skills.

 

[Hurricane4]

The amount of the tire “buldge” on a narrow wheel may be causing part of the problem. Follow what Axhammer posted. Very good info.

 

[andyknight3]

Thanks for the replies! I'm planning on running 4.10s so shouldn't be too hard to find whatever axle I end up with. I thought about the 8.8 and while it would be stronger, the D44 I already have seems cheaper and easier and will probably hold up to 35s just fine. Additionally I'm a little skeptical of the overall strength of shortening the 8.8 like that as I've read cutting and welding the axle tubes together can be a a little sketchy, although I'm certainly open to being convinced otherwise.

 

[Axhammer]

Thanks for the replies! I'm planning on running 4.10s so shouldn't be too hard to find whatever axle I end up with. I thought about the 8.8 and while it would be stronger, the D44 I already have seems cheaper and easier and will probably hold up to 35s just fine. Additionally I'm a little skeptical of the overall strength of shortening the 8.8 like that as I've read cutting and welding the axle tubes together can be a a little sketchy, although I'm certainly open to being convinced otherwise.

Start with an 8.8 out of a F-150. Cut and narrow to width you want, narrow both tubes. Weld on Ford 9” large wheel bearings ends. Order new aftermarket axles with 5 on 5.5.

Or you could do the same with an AMC-20 out of a FSJ. The AMC-20 with thicker tubes and new aftermarket axles would be strongest of them all. Just another option.

 

[andyknight3]

That makes sense - I was thinking cutting a section from the middle of the tubes and butt welding it back together. Doing it with the 9 inch bearings seems much easier/stronger. Still I'm not sure I would bother shortening an 8.8, at that point it seems like it would make more sense to cut down a D44 from a J truck to 61" wms and then just put an 8.8 from an explorer (59 1/2" wms I believe) with axle shafts drilled for 5x5.5 in the back. Just leaves 1 axle to cut and modify instead of 2.

Are you suggesting the 8.8 because you think it will fit better or because you don't think the CJ7 D44 I have isn't strong enough for the rear?

 

[80cj]

The amount of the tire “buldge” on a narrow wheel may be causing part of the problem. Follow what Axhammer posted. Very good info.

That's a good point and wider wheels will lessen the buldge thus less interference with springs.

 

[andyknight3]

That's a good point and wider wheels will lessen the buldge thus less interference with springs.

That makes total sense and I definitely plan on going to a bigger wheel when I move up to 35x12.5s although I expect I’ll still need some more width out of the axles to clear them.

 

[Axhammer]

If you can cut & weld the FSJ front Dana 44 to 57” WMS width, you can cut & weld the 8.8 as well. The skill set is about the same. That’s why I tossed it out there.

I guess that OEM 1986 WT Dana 44 would be the cheapest way to go, as long as you already have it.

The front track wider than the rear track was common on some rigs back in the day. As long as that didn’t bother you, the front FSJ Dana 44 cut down to 57” WMS width, and the rear Dana 44 at 55” WMS width would be fine for a CJ-7 on 35’s.

I believe the 8.8 is stronger than a Dana 44, so that’s the direction I would go, if I was dead set on running 35’s.

I like the 8.8 because they are pleantifull & cheap at the Pick-N-Pull or CL.

The AMC 20 gets a bad reputation from the two piece axles AMC used in the CJ-7’s. The AMC 20’s from a FSJ are much better, but are a little wide for a CJ-7, unless you cut & narrow it.

You could always go Dana 60, but might be overkill for 35’s.

 

[andyknight3]

I do really like the 8.8 and the security of having a reared that's probably a little bit more then what I need. Probably a little cheaper and easier to use the D44 what I have but the words "cheap" and "easy" don't exactly go with "jeep." Besides, by the time I sell the D44 I can buy an 8.8 and have some leftover for upgrades.

If I do go with the 8.8 then I suppose it's just a matter of deciding where I want to end up as far as total width in picking a front axle.

 

[CSP]

If you can cut & weld the FSJ front Dana 44 to 57” WMS width, you can cut & weld the 8.8 as well. The skill set is about the same. That’s why I tossed it out there.

While the skills are about the same, an alignment bar and the correct pucks is an absolute must to get the ends on straight for a rear axle.

 

[andyknight3]

Yes! It seems relatively straightforward to do but I see no good way to do this without a jig and they’re cheap enough. I have a deal pending on a j10 D44 and an explorer 8.8. Right now I’m planning on probably cutting down the D44 and running the 8.8 at stockish width but haven’t decided on going the 9 inch bearing end setup or the Yukon ultimate 88 kit.

 

[whodatschrome]

If I were rolling 35” tires, I’d do whatever it takes to go with about 60” wide axles. The extra stability is nice both on and off road. Plus there’s more room between the tires and leaf springs. A FSJ Dana 44 can be the donor. As for the rear axle, well the guys over in the TJ forum seem to think that a wrangler Dana 35 can be built to be stronger than a D60, but I’ll let you argue with them on that option. Maybe a rear D44 out of a Scout (right bolt pattern)? The 8.8 is strong, but I don’t like how the lip on the housing hangs down (wrong bolt pattern). Another option is a Ford 9” (right bolt pattern). I can’t remember what widths they came in though.

 

[andyknight3]

I’ve come to agree on the width - trying to make use of the CJ-7 D44 I already have was nudging me towards staying narrow but the more I’ve thought about it and based on what others have said on the forum I think that with 35s I’m better off with a little more track width. Not all FSJ axles are the same and cutting the J10 Dana 44 seems like a better option then running a Wagoneer D44 because a cut J10 axle nets a similar wms width (61” vs 60”) but has greater wms to spring clearance. The stock explorer 8.8 is about 59.5. I don’t know anything about the wrangler 35 so can’t speak to that at all. A scout d44 would be a fine swap but they’re not nearly as plentiful or as cheap as the 8.8 and the 8.8 is stronger anyways. A 9 inch would be an even stronger option but I rarely see them the right width and I don’t love the low pinion (I’ve got plans for a Dana 300/doubler swap and want to keep options open for a 5 speed and worry about a very short driveshaft operating at an extreme angle) and for 35s the 8.8 ought to be plenty strong. Bolt pattern is easy enough to change - the Yukon ultimate 88 kit comes drilled for 5x5.5 or I go the 9 inch bearing end route and ordering custom shafts anyway…

 

[whodatschrome]

I’ve come to agree on the width - trying to make use of the CJ-7 D44 I already have was nudging me towards staying narrow but the more I’ve thought about it and based on what others have said on the forum I think that with 35s I’m better off with a little more track width. Not all FSJ axles are the same and cutting the J10 Dana 44 seems like a better option then running a Wagoneer D44 because a cut J10 axle nets a similar wms width (61” vs 60”) but has greater wms to spring clearance. The stock explorer 8.8 is about 59.5. I don’t know anything about the wrangler 35 so can’t speak to that at all. A scout d44 would be a fine swap but they’re not nearly as plentiful or as cheap as the 8.8 and the 8.8 is stronger anyways. A 9 inch would be an even stronger option but I rarely see them the right width and I don’t love the low pinion (I’ve got plans for a Dana 300/doubler swap and want to keep options open for a 5 speed and worry about a very short driveshaft operating at an extreme angle) and for 35s the 8.8 ought to be plenty strong.

The only reason for going with a 300 and a doubler would be for going super slow. The only terrain I personally would be driving that slow is either rocks or more rocks. And if that’s the same case for you, I’d tend to look to go a little bit wider than 60”...maybe 63” to 65”?

FYI, I have a Klune V behind my D300.

 

[andyknight3]

That’s a fair point and the merits of a doubler/Dana 300 is a subject for a whole other thread. I’ll be the first to say that I probably don’t really “need” one - I just really like the setup and the options it gives.