Help me make a decision on upgrading my axles

mjonesjr84

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I'm pondering swapping axles in my TJ instead of regearing/locking the factory Dana 30/35. I can pick up a set of TJ Rubicon axles for around $5k locally that are geared at 4.10 and air locked OR I can get a set of Dynatrac ProRock 44 front and a ProRock 60 rear from a friend that are out of a JK with 5k miles on them, geared to 4.88 with Eaton E-Lockers for $10k. I know that with the Dynatrac axles they are roughly 5" wider and will have to have the TJ brackets welded on.

Which would you do? I'm leaning towards the TJ Rubicon axles since they are bolt in and are the factory TJ width.
 
What size tires do you plan to run? Are the TJ D44s equipped with chromoly axle shafts and are the pumps included? If you need to regear, install new axle shafts, and source locker pumps the TJ D44s will be around $9,000.
 
What are you wanting to do with the Rubicon axles that you can’t do with your Dana 30/Dana 35 for less money?

What tire size are you planning? 4.10 with AX-15 is only good for a 29-31” tire.
 
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What size tires do you plan to run? Are the TJ D44s equipped with chromoly axle shafts and are the pumps included? If you need to regear, install new axle shafts, and source locker pumps the TJ D44s will be around $9,000.
I currently don't plan on going any bigger than 33's that are on it now. The Dana 44's are the stock OEM Rubicon axles and would come with the factory air pumps.
 
What are you wanting to do with the Rubicon axles that you can’t do with your Dana 30/Dana 35 for less money?

What tire size are you planning? 4.10 with AX-15 is only good for a 31” tire.
I currently have 3.73 gears and the NV3550 in my 2000. I'm happy with the 3.73 on the highway, but want a little more in town; that is why I was thinking 4.10's. From what I've been looking at, the 44's would be about the same cost to regear and lock my current 30/35 axle.

I mainly daily drive and mild off road the TJ. I don't "need" the Dynatrac axles nor at this point will I use them to their full potential. That isn't to say that down the road this won't be a dedicated trail rig.
 
I currently don't plan on going any bigger than 33's that are on it now. The Dana 44's are the stock OEM Rubicon axles and would come with the factory air pumps.

You want 4.88 gears.

It’s better to do it right the first time.

You’re best setup for cost, weight, efficiency, clearance, and capability is a Dana 30 (with chromoly shafts) and Super35 regeared and locked at 4.88.
 
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Why 4.88's? Won't those destroy any mpg on the highway?

You say 4.56 and 33's are perfect for the 5-speed.

No, it won’t destroy your mpg on the highway or in town. It may even improve, but any change will be so slight it will be imperceptible. Common myth. See other thread on same topic that happened yesterday and today about same AX-15 transmission.

4.56 is not enough for 33’s and either 5-speed transmission Jeep offered (AX-15 and NV3550)
IMG_3209.webp

See those rpm’s at 70mph? 2500’ish? That is not ideal. You want 2750rpm at 70mph to have best shift points and be right.
 
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No, it won’t destroy your mpg on the highway or in town. It may even improve, but any change will be so slight it will be imperceptible. Common myth. See other thread on same topic that happened yesterday and today about same AX-15 transmission.
I'm guessing the AX-15 and the NV3550 that I have are similar in gear ratios?

What about the width on the JK axles? If I go that route, I'll probably use 5x5 to 5x4.5 wheel adapters for now.
 
I'm guessing the AX-15 and the NV3550 that I have are similar in gear ratios?

What about the width on the JK axles? If I go that route, I'll probably use 5x5 to 5x4.5 wheel adapters for now.

Yes, the ratios in both 5-speeds are very similar. I’m saying that for a reason. Typical recommendation for the NV3550 and 33’s is 4.88, but for some idiotic reason people keep suggesting that the AX-15 and 33’s needs 4.56. It’s stupid. The numbers tell all in the earlier post. You want 2750rpm at 70mph for best all around driveability. Remember, this is not just about a 33” taller tire. It’s also heavier and wider and causing more road friction, so you need those deeper gears to help turn the tire against all those forces.

The JK axles will by no means be a bolt on affair. It’s a lot of work. One easy piece is moving from 5x5 to 5x4.5 with an adapter. JK axles are wider. Typically used for going to 37’s.
 
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I'm pondering swapping axles in my TJ instead of regearing/locking the factory Dana 30/35. I can pick up a set of TJ Rubicon axles for around $5k locally that are geared at 4.10 and air locked OR I can get a set of Dynatrac ProRock 44 front and a ProRock 60 rear from a friend that are out of a JK with 5k miles on them, geared to 4.88 with Eaton E-Lockers for $10k. I know that with the Dynatrac axles they are roughly 5" wider and will have to have the TJ brackets welded on.

Which would you do? I'm leaning towards the TJ Rubicon axles since they are bolt in and are the factory TJ width.

I’m not going to engage anyone calling opinions stupid. I’ll give my opinion, and you can use any or none of it.

I went from 30/35 with 4.10’s and 33’s and put in Rubicon 44’s with lockers and 4.88’s. I put 35’s on, and it’s good, but not hugely different.

4.56 or 4.88, I think people are over thinking things sometimes.

I would wager a drink that no one on 33’s is actually that measurement, that goes into the calculator to get those numbers. I bet if they measure from center hub to ground it would be less than 50% of a 33, so essentially they should be inputting 32’s or even 31.5’s before making all kinds of declarations.

If you want to get that exact, that’s what you have to do.

The 44/60, JK, no way I’d do that, too much work and going custom for me personally.

The Rubicon axles at 4.10 would probably do you really well.

You can also sell your current axles and bring down the Net cost. Unless you regear yourself, it ain’t cheap to put new gears and axles and labor into the 30/35, not cheap at all with labor.
 
Rubi axles are nice. But not 5k$ nice. They have weak aging lockers that can't be fixed. I will consider mine liabilities until i get arb's and chromoly shafts.
I was thinking that getting the Rubicon 44's and putting an e-locker in it and maybe upgrading gears would get me close to the cost of the Dynatrac JK axles.
 
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I’ve never tried 4.88’s, but 4,56 on 33’s with the NV3550 is great. Could 4.88 be better? Idk, maybe? Arguing about the difference is kinda silly. It’s a difference of 7%.

But can I just say that the prices being quoted in this thread are insane. $10k for what amounts to factory axles??
 
I’ve never tried 4.88’s, but 4,56 on 33’s with the NV3550 is great. Could 4.88 be better? Idk, maybe? Arguing about the difference is kinda silly. It’s a difference of 7%.

But can I just say that the prices being quoted in this thread are insane. $10k for what amounts to factory axles??

I hear you, but look at the pricing. To regear, get a Super 35 Revolution parts etc, you’re looking $2,250-$2500 for that axle.

I didn’t go price the entire Dana 30, but it’s close. That’s about $5k.

If you buy the 44’s you can sell you 30/35, even at a crazy $5k you end up better $ wise.






https://wranglertjforum.com/threads/super-35-cost.69877/
 
I hear you, but look at the pricing. To regear, get a Super 35 Revolution parts etc, you’re looking $2,250-$2500 for that axle.

I didn’t go price the entire Dana 30, but it’s close. That’s about $5k.

If you buy the 44’s you can sell you 30/35, even at a crazy $5k you end up better $ wise.






https://wranglertjforum.com/threads/super-35-cost.69877/

And you wind up with bad gearing and shitty lockers. It isn't a good comparison.
 
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So I've decided to buy a new set of axles from ECGS. I'm going with Dana 44's front and back with 4.88 gears and ARB lockers. The rear I am going to go with the upgraded SET 20 bearings and disc brakes. The fronts I'm going to get new knuckles and bearings from them so they are 100% bolt in.
 
Just for the record, I would like to state that 4.10s and 33s sucks… even with no elevation change at low altitude.
I'm currently running 33's with 3.73 gears. It isn't horrible, but not great either.
 
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