Build my 30 or swap for 44?

[Thunder Mass]

I got some good info a few months ago regarding running 33s on my 30/44 combo, which is very much appreciated. But, I'm leaning towards 35s now, and looking for a little bit more help in my decision. I was ready to go ahead and re-gear my 30/44 with Evolution chromoly ring/pinion, and shafts. Lockers are also a possibility, rear and maybe front. Hence the desire for the chromoly all around.

So I was talking to a guy at a local shop, whos LJ is pretty much everything I want mine to be. Only difference was, he doesn't recommend building the 30, as after the chromolys are put in, the ring is the new week point, and better break a shaft than a ring. Not a bad thought, I guess, but not sure I agree with letting the 30 break. Especially if I wanna lock it.

He did make one interesting point, though, that I'm a bit confused on: leave it 27 spline, because it'll give it some flex? 30 spline and there won't be any give? I dunno, interesting idea, just not sure if it works that way.

So, my options are to build my 30, or swap it. Either with a TJ Rubi; kinda hard to find, it seems. Or, buy/build an aftermarket one. I haven't spent much time looking into building, but if I get the axle housing, and I was going to get new shafts, ring/pinion, MAYBE an ARB locker (open diffs don't seem too expensive), knuckles from Black Magic/Vanco, what else is there I'd need to build?

Last questions are... would it even be worth doing a high pinion 30 swap? Would a Dana 44 front (TJ or aftermarket) be stronger stock than a built 30? Can I use an ARB compressor with Rubi lockers? I'll look into that one more on my own...

Thanks guys. Hopefully I can just build this soon and show it off! And wheel it, of course.

 

[Chris]

Waste of time and money if you ask me.

A Dana 30 is (when built) is more than up to the task of handing 35" tires. @Jerry Bransford and all those guys who wheel down in Johnson Valley are running a lot of Dana 30 axles on 35" tires without issue. My thought is that if it can handle that sort of rugged terrain on 35s, then anything we can do up here in the PNW pales in comparison (mostly).

Also, swapping a Dana 30 for a Rubicon Dana 44 front wouldn't gain you much other than a bigger ring and pinion.

An ARB compressor also will not work with Rubicon lockers. They require some super small amount of psi. Can't recall what it is, but it's something that you need the factory locker pumps for.

 

[Thunder Mass]

Waste of time and money if you ask me.

A Dana 30 is (when built) is more than up to the task of handing 35" tires. @Jerry Bransford and all those guys who wheel down in Johnson Valley are running a lot of Dana 30 axles on 35" tires without issue. My thought is that if it can handle that sort of rugged terrain on 35s, then anything we can do up here in the PNW pales in comparison (mostly).

Also, swapping a Dana 30 for a Rubicon Dana 44 front wouldn't gain you much other than a bigger ring and pinion.

An ARB compressor also will not work with Rubicon lockers. They require some super small amount of psi. Can't recall what it is, but it's something that you need the factory locker pumps for.

That's exactly what I was thinking. So many people here use built 30s on rougher terrain than I'll likely see, and they're holding up well.

Right, besides ring and pinion, the 44 isn't really much different.

Yeah, I thought I saw somewhere that the rubi lockers run on much lower PSI. Would be nice if they worked together, though I'd bet the ARBs are better, anyway.



Any opinion on sticking with 27 spline? Other than that question, I think I'll be fine with building my 30s. Thanks for the info.

 

[JDS123]

I've run an ARB locked front 30 with stock shafts and 33's for the last few years with no problems. I recently went to 35's and installed Revolution's 4340 big u-joint 27 spline shafts. I will let you know how it holds up once I get it wheeling.

Overall, I have a couple grand into my front 30 when you include brakes, shafts, gearing, and lockers. That is a little hard to swallow as I'm not 100% sure it is strong enough for my needs (even though many here say it is). I'm not so worried about the shafts, housing, ball joints, etc... as I am the ring and pinion. Only time will tell, I may be wrong.

 

[Jerry Bransford]

That's exactly what I was thinking. So many people here use built 30s on rougher terrain than I'll likely see, and they're holding up well.

Right, besides ring and pinion, the 44 isn't really much different.

Yeah, I thought I saw somewhere that the rubi lockers run on much lower PSI. Would be nice if they worked together, though I'd bet the ARBs are better, anyway.



Any opinion on sticking with 27 spline? Other than that question, I think I'll be fine with building my 30s. Thanks for the info.

Good quality 4340 alloy 27 spline inner/outer shafts for your front Dana 30 like from Revolution Gear are more than up to 35" tires, a front locker, and tough trails. That's exactly what I replaced my broken passenger-side OE Dana 30 shaft with and no more problems after that.

And yes, the Rubicon lockers run on 5 psi vs. the ARB's 90 or so psi. I'd definitely take ARB's air lockers over my present Rubicon lockers.

 

[Chris]

That's exactly what I was thinking. So many people here use built 30s on rougher terrain than I'll likely see, and they're holding up well.

Right, besides ring and pinion, the 44 isn't really much different.

Yeah, I thought I saw somewhere that the rubi lockers run on much lower PSI. Would be nice if they worked together, though I'd bet the ARBs are better, anyway.



Any opinion on sticking with 27 spline? Other than that question, I think I'll be fine with building my 30s. Thanks for the info.

The other thing you have to remember about the front axle (and why you don't need as beefy as front axle for the front as you do for the rear), is that the TJ is still primarily a RWD vehicle. The majority of power is going to the rear wheels, which is why the rear axle usually always has to be stronger than the front.

Yes, if I was going through the effort of putting in new axles in a non-Rubicon model, I would ditch the factory lockers and just put ARB lockers in there. Those locker pumps on the Rubicon models go bad, and since Mopar no longer makes replacements, you have to source used ones, and they've become astronomically expensive last I heart.

With 35" tires it certainly wouldn't hurt to go with 30 spline axle shafts. The outer axle shaft remains 27 spline, but the inner is upgraded to a 30 spline.

I had wondered if it would be beneficial to have 30 spline outers as well, but that would require aftermarket hubs and other stuff.

I actually read something Blaine had written a while back in response to this, mentioning that 27 spline outers are fine, as that's not really a common break point you see on TJs, even with 35s.

However, I think that a 27 spline alloy axle shaft would actually be fine for the front axle.

 

[derekmac]

And yes, the Rubicon lockers run on 5 psi vs. the ARB's 90 or so psi. I'd definitely take ARB's air lockers over my present Rubicon lockers.

Have you had any/many issues with the Rubi lockers?

 

[Jerry Bransford]

Have you had any/many issues with the Rubi lockers?

So far just a leaky air bladder inside one of the actuators, that was 8-9 years ago. Other than that no.

 

[derekmac]

So far just a leaky bladder inside one of the actuators, that was 7-9 years ago. Other than that no.

Knowing what you put your Jeep through, that makes me feel good about mine.

If one were to fail, would you find a stock replacement or switch to an ARB?

 

[Jerry Bransford]

If one were to fail, would you find a stock replacement or switch to an ARB?

That depends on my financial condition at the time (I am retired) and how cheaply a used Rubicon locker could be obtained. If $$$ is no problem at the time I'd definitely replace it with an ARB.

 

[Thunder Mass]

I've run an ARB locked front 30 with stock shafts and 33's for the last few years with no problems. I recently went to 35's and installed Revolution's 4340 big u-joint 27 spline shafts. I will let you know how it holds up once I get it wheeling.

Overall, I have a couple grand into my front 30 when you include brakes, shafts, gearing, and lockers. That is a little hard to swallow as I'm not 100% sure it is strong enough for my needs (even though many here say it is). I'm not so worried about the shafts, housing, ball joints, etc... as I am the ring and pinion. Only time will tell, I may be wrong.

That's my worry too, as the guy at the shop. But at the same time, just because the ring and pinion are the weak points, doesn't mean they're too weak, I suppose. Maybe I'm wrong too. But, sounds like it's working for you. Thanks.

Good quality 4340 alloy 27 spline inner/outer shafts for your front Dana 30 like from Revolution Gear are more than up to 35" tires, a front locker, and tough trails. That's exactly what I replaced my broken passenger-side OE Dana 30 shaft with and no more problems after that.

And yes, the Rubicon lockers run on 5 psi vs. the ARB's 90 or so psi. I'd definitely take ARB's air lockers over my present Rubicon lockers.

I would like to go to Moab, maybe next year. But aside from that, I've seen where you go with your 30, and it's way more challenging than I'll likely see up here. If yours is holding up with all of that abuse, I feel pretty confident in my. Thanks.

And 5 vs 90? That's crazy.

The other thing you have to remember about the front axle (and why you don't need as beefy as front axle for the front as you do for the rear), is that the TJ is still primarily a RWD vehicle. The majority of power is going to the rear wheels, which is why the rear axle usually always has to be stronger than the front.

Yes, if I was going through the effort of putting in new axles in a non-Rubicon model, I would ditch the factory lockers and just put ARB lockers in there. Those locker pumps on the Rubicon models go bad, and since Mopar no longer makes replacements, you have to source used ones, and they've become astronomically expensive last I heart.

With 35" tires it certainly wouldn't hurt to go with 30 spline axle shafts. The outer axle shaft remains 27 spline, but the inner is upgraded to a 30 spline.

I had wondered if it would be beneficial to have 30 spline outers as well, but that would require aftermarket hubs and other stuff.

I actually read something Blaine had written a while back in response to this, mentioning that 27 spline outers are fine, as that's not really a common break point you see on TJs, even with 35s.

However, I think that a 27 spline alloy axle shaft would actually be fine for the front axle.

Right, as long as I don't lose RWD, the 30 will only see 50% power at most. I thought about skipping the chromoly rear, but I'd rather just do it.

I didn't wanna assume that the Rubi lockers weren't as good, but I assumed they weren't as good. That's good to know. And I think I'll just go with 30 spline. Thanks.

 

[Chris]

Right, as long as I don't lose RWD, the 30 will only see 50% power at most. I thought about skipping the chromoly rear, but I'd rather just do it.

I didn't wanna assume that the Rubi lockers weren't as good, but I assumed they weren't as good. That's good to know. And I think I'll just go with 30 spline. Thanks.

I'd put chromoly shafts in the rear. Better safe than sorry, especially with 35s.

I've talked to a lot of hardcore wheelers who wheel with the factory Rubicon lockers. Most of them seem to say that there is no doubt an aftermarket locker such as an Eaton or ARB is undoubtedly better, but the factory Rubicon lockers are actually better than most would think, and should remain trouble free as long as you don't beat the snout out of the Jeep.

 

[Jerry Bransford]

I didn't wanna assume that the Rubi lockers weren't as good, but I assumed they weren't as good. That's good to know. And I think I'll just go with 30 spline. Thanks.

I don't believe the significant added expense of going to 30 splines up front is warranted, not even close. It's not just the cost of the 30 spline shafts, you have to convert the hubs to 30 spline too to see any benefit of 30 spline shafts. Converting the hubs to 30 spline is not inexpensive. Milemarker's 30 spline unit bearing hubs are not worth installing which leaves you with converting to manual hubs up front to be able to run 30 spline shafts which is not cheap or easy at all.

I pounded on my front Dana 30 after converting it to 4340 alloy 27 spline shafts with 35" tires and an automatic front locker and it was solid afterward. Those shafts were stronger than the front OE carbon steel 30 spline shafts that come in the Rubicon's Dana 44.

 

[Thunder Mass]

I'd put chromoly shafts in the rear. Better safe than sorry, especially with 35s.

I've talked to a lot of hardcore wheelers who wheel with the factory Rubicon lockers. Most of them seem to say that there is no doubt an aftermarket locker such as an Eaton or ARB is undoubtedly better, but the factory Rubicon lockers are actually better than most would think, and should remain trouble free as long as you don't beat the snout out of the Jeep.

Exactly. I MIGHT be overbuilding slightly, but I'd rather overbuild than under build.

I was really thinking about the Eaton E lockers, partially because of the price the ARBs including the compressor. But there are mixed reviews on how the Eatons unlock and lock again when changing direction. And while I like the idea of the manual Ox lockers... there's iffy opinions on them as well. So I feel like I really should do ARB. I could do auto in the front, but I think I'd prefer manual all around.

I don't believe the significant added expense of going to 30 splines up front is warranted, not even close. It's not just the cost of the 30 spline shafts, you have to convert the hubs to 30 spline too to see any benefit of 30 spline shafts. Converting the hubs to 30 spline is not inexpensive. Milemarker's 30 spline unit bearing hubs are not worth installing which leaves you with converting to manual hubs up front to be able to run 30 spline shafts which is not cheap or easy at all.

I pounded on my front Dana 30 after converting it to 4340 alloy 27 spline shafts with 35" tires and an automatic front locker and it was solid afterward. Those shafts were stronger than the front OE carbon steel 30 spline shafts that come in the Rubicon's Dana 44.

I didn't realize the hubs would have to be changed as well; shows what I know. I'll have to change the Revolution I'm looking at. Thanks for that. I do think it would be cool to do manual locking hubs, though, in the future.

Nice. I feel pretty confident about this again. Thanks.

 

[Chris]

Exactly. I MIGHT be overbuilding slightly, but I'd rather overbuild than under build.

I was really thinking about the Eaton E lockers, partially because of the price the ARBs including the compressor. But there are mixed reviews on how the Eatons unlock and lock again when changing direction. And while I like the idea of the manual Ox lockers... there's iffy opinions on them as well. So I feel like I really should do ARB. I could do auto in the front, but I think I'd prefer manual all around.

My intention has always been to get Eaton E-Lockers if the factory Rubicon lockers ever fail. I hear good things about them!

 

[Jerry Bransford]

I do think it would be cool to do manual locking hubs, though, in the future.

Keep in mind that manual hubs only do one thing your present unit bearing hubs don't do... they can be unlocked. They don't help improve mpg, they don't help while offroading, and they don't help while driving around town. Their only real benefits are they are rebuildable and they give a means to run 30 spline shafts.

 

[Thunder Mass]

My intention has always been to get Eaton E-Lockers if the factory Rubicon lockers ever fail. I hear good things about them!

I might be overthinking it, but I don't like how they unlock when changing direction. Sorry, don't wanna say they're bad. And, my opinion is based on others, not my own. I'm still thinking about them as well. Haven't decided yet.

 

[Thunder Mass]

Keep in mind that manual hubs only do one thing your present unit bearing hubs don't do... they can be unlocked. They don't help improve mpg, they don't help while offroading, and they don't help while driving around town. Their only real benefits are they are rebuildable and they give a means to run 30 spline shafts.

I've heard the MPG argument before, and even IF it does help, it'll be minor, and it'll take a very long time to see returns, if ever.

My interest in them was mostly if I broke something in the axle, I could unlock the hubs and still drive without the axle chewing itself up even more. Another reason why I wanted my front axles stronger is IF I really messed up my rear I could unlock it and have a FWD Jeep. Temporarily, of course. But maybe that's a bad idea?

 

[Jerry Bransford]

You can drive in FWD on the street without beefing it up at all, it's more than strong enough for that in stock form.

Mpg gains were common with older axle/bearing designs like with the early CJs but there are no mpg benefits with a TJ. I drive my TJ about equally with my front hubs locked/unlocked and there's no difference in mpg or in anything I can feel. I have to look at my hubs to see if they're locked or not.

 

[Thunder Mass]

Sorry, I shouldn't have said FWD. I meant FRONT wheel drive. If something blew up in the rear axle.