Looking for input on an off-road capable, daily driver build

[ClayAkers]

Lots of great info here, folks! Thanks to everyone for the input and suggestions.

I’m thinking the Super 35 rear will save a good chunk, and will help me justify the extra for the disc brake conversion.

For those who have re-reared: How did you determine the optimal ratio?

If I’m correctly using the calculator on GrimJeeper, it looks like 4.56 will put me back to factory (42RLE w/33s). How much of a difference will 4.88 or 5.13 be?

 

[SvtLdr]

For those who have re-reared: How did you determine the optimal ratio?

If I’m correctly using the calculator on GrimJeeper, it looks like 4.56 will put me back to factory (42RLE w/33s). How much of a difference will 4.88 or 5.13 be?

Are you 100% sticking with the 33" tires? Or is there a chance you'll go bigger?

 

[Claytone]

Going just a bit past stock RPMs is a good idea. Your new tires are heavier, and the lift will add some wind resistance. A couple hundred extra RPM will help keep the power up.
Grimm showed my "return to factory" ratio was approx 4.2ish, I went with 4.56 vs 4.10. It drives great, and the power is good.

 

[Irun]

Never heard of a rubicrawler. What is it?

Having owned two Rubicrawlers, with a third waiting to be installed, they're not as good of an option, with stock 231 and 241 transfer cases, as most think. Here's a break down of all the ratio possibilities.

Ratio possibilities with a - Stock New Process 231/241 are a 2.72:1 and a 7.40:1

Stock NP Rocktrac are a 2.72:1, 4.0:1 and a 10.88:1 Atlas 2.0 are 2.0:1, 2.72:1 and a 5.44:1

Atlas 3.0 are 2.72:1, 3.0:1 and a 8.16:1

Atlas 3.8 are 2.72:1, 3.8:1 and a 10.44:1

Atlas 4.3 are 2.72:1, 4.3:1 and a 11.70:1

Atlas 5.0 are 2.72:1, 5.0:1 and a 13.60:1

Out of all of them, the Rubicrawler mated to a 2.0 Atlas, seen in red, is the best option. The problem here is this is a $5K+ upgrade!

The reason the others aren't a good option, above 5.44:1, is that the amount of torque applied with those ratios is so high you will break u joints, hub kits, and axle shafts. Provided you don't use the 10.88:1 option with the Rubicon 241, there is value though, because you get both the 2.72:1 and 4:1 option.

 

[ClayAkers]

Are you 100% sticking with the 33" tires? Or is there a chance you'll go bigger?

I like the 33s and will probably stay there. Probably. I can’t see going any bigger than 35s, but even that’s a stretch… literally. I’ve got short legs and it’s hard enough to get in the Jeep as it is XD

 

[ClayAkers]

Having owned two Rubicrawlers, with a third waiting to be installed, they're not as good of an option, with stock 231 and 241 transfer cases, as most think. Here's a break down of all the ratio possibilities.

Ratio possibilities with a - Stock New Process 231/241 are a 2.72:1 and a 7.40:1

Stock NP Rocktrac are a 2.72:1, 4.0:1 and a 10.88:1 Atlas 2.0 are 2.0:1, 2.72:1 and a 5.44:1

Atlas 3.0 are 2.72:1, 3.0:1 and a 8.16:1

Atlas 3.8 are 2.72:1, 3.8:1 and a 10.44:1

Atlas 4.3 are 2.72:1, 4.3:1 and a 11.70:1

Atlas 5.0 are 2.72:1, 5.0:1 and a 13.60:1

Out of all of them, the Rubicrawler mated to a 2.0 Atlas, seen in red, is the best option. The problem here is this is a $5K+ upgrade!

The reason the others aren't a good option, above 5.44:1, is that the amount of torque applied with those ratios is so high you will break u joints, hub kits, and axle shafts. Provided you don't use the 10.88:1 option with the Rubicon 241, there is value though, because you get both the 2.72:1 and 4:1 option.

Thanks for the breakdown! Instead of a rubicrawler, I think I’ll put that money towards something else.

 

[SvtLdr]

I like the 33s and will probably stay there. Probably. I can’t see going any bigger than 35s, but even that’s a stretch… literally. I’ve got short legs and it’s hard enough to get in the Jeep as it is XD

It's always best to firmly decide on a tire size and build around that. This is essential for gear ratio selection. 5.13 is going to be the recommendation for 33" tires and your powertrain. Unfortunately, that will be the deepest gearing your axles can support. So going to 35's will provide less than stellar results on the highway.
https://wranglertjforum.com/threads...angler-tj-lj-and-other-re-gearing-faqs.17063/
That being said, I find it helpful to also consider your intended uses. If your Jeep sees more highway/ commuting use than it does off road then I tend to step down the gearing one notch to 4.88. You'll find others who say that 4.88 gears are ok if you're not heavy into rock crawling. If your Jeep is primarily used off road I'd go to the max with 5.13.

 

[NashvilleTJ]

Having owned two Rubicrawlers, with a third waiting to be installed, they're not as good of an option, with stock 231 and 241 transfer cases, as most think. Here's a break down of all the ratio possibilities.

Ratio possibilities with a - Stock New Process 231/241 are a 2.72:1 and a 7.40:1

Stock NP Rocktrac are a 2.72:1, 4.0:1 and a 10.88:1 Atlas 2.0 are 2.0:1, 2.72:1 and a 5.44:1

Atlas 3.0 are 2.72:1, 3.0:1 and a 8.16:1

Atlas 3.8 are 2.72:1, 3.8:1 and a 10.44:1

Atlas 4.3 are 2.72:1, 4.3:1 and a 11.70:1

Atlas 5.0 are 2.72:1, 5.0:1 and a 13.60:1

Out of all of them, the Rubicrawler mated to a 2.0 Atlas, seen in red, is the best option. The problem here is this is a $5K+ upgrade!

The reason the others aren't a good option, above 5.44:1, is that the amount of torque applied with those ratios is so high you will break u joints, hub kits, and axle shafts. Provided you don't use the 10.88:1 option with the Rubicon 241, there is value though, because you get both the 2.72:1 and 4:1 option.

The best option you described is the exact ratio set I run in my 4 sp Atlas, and it works great in my rig. Prolly cheaper than doing the Rubicrawler solution. The 4 sp atlas is basically an Atlas case with a 2.72 planetary in front of it - the same setup as a Rubicrawler in front of a 2sp Atlas. One advantage of going the Rubicrawler route to get there is that solution is a lot shorter than the 4sp.

And you are not kidding about the torque. In 5.44:1 in first gear, I’m putting about 50,000 foot pounds to the axle shafts.

 

[Apparition]

The best option you described is the exact ratio set I run in my 4 sp Atlas, and it works great in my rig. Prolly cheaper than doing the Rubicrawler solution. The 4 sp atlas is basically an Atlas case with a 2.72 planetary in front of it - the same setup as a Rubicrawler in front of a 2sp Atlas. One advantage of going the Rubicrawler route to get there is that solution is a lot shorter than the 4sp.

And you are not kidding about the torque. In 5.44:1 in first gear, I’m putting about 50,000 foot pounds to the axle shafts.

I'm looking forward to having one jeep with a Rubicrawler and another with an Atlas so I can compare them.

 

[Irun]

And you are not kidding about the torque. In 5.44:1 in first gear, I’m putting about 50,000 foot pounds to the axle shafts.

I learned the hard way that you can't use the 10.88:1 when you have a 241J. Brakes won't stop you and, at effectively 100,00+ ft lbs, stuff goes bang!

 

[ClayAkers]

I'm confused. I contacted a respected local shop about getting this work done, and got some info that leaves me scratching my head. Maybe y'all can help.

He's trying to steer me toward Eaton e-lockers vs ARB. (Maybe it's an availability issue.) He spoke highly of Eaton, but I'm still leaning toward ARB. Please let me know if you agree of disagree. (With the Dana 35 rear, I want to upgrade both front and rear with 30-spline lockers and axles.)

Also, I was thinking 5.13 gears for my 4.0L with 42RLE and 33" tires (based on Grim Jeeper). The guy at the local shop is saying that's overkill and that 4.10 would be plenty, but he wouldn't recommend anything deeper than 4.88. (Again, maybe a supply issue?) I need to be able to run 75mph for hours to get out of Texas wheel in CO, UT, CA, etc. Basically, anywhere I want to go is going to put me on the Interstate for hours, so I want a Jeep that can do that while still being fun off-road. (Highway speed of at least 75mph is the priority.)

For those not familiar with the area, there's almost no public land in TX and it takes about 8 hours to get out of the state heading west toward NM, CO, UT, etc, so having good road manners and gas mileage is a must.

In summary, I want to know if I'm crazy wanting to go with 5.13 gears and ARB lockers in my non-Rubicon TJ (4.0L, 42RLE, NP231, 33" tires)?

Or am I dealing with someone trying to make a sale when supplies are tight?

 

[psrivats]

In summary, I want to know if I'm crazy wanting to go with 5.13 gears and ARB lockers in my non-Rubicon TJ (4.0L, 42RLE, NP231, 33" tires)?

I have a 4.0/42RLE rubicon with 33" BFG KO2s and 5.39 gears are pretty awesome with it. I had 4.88s before which was insufficient and I don't think 5.13 would have been nearly as good as what I have today. I would not recommend anything under 5.13 unless you ONLY drive on very flat roads all the time.

 

[steelhd]

You’ll get turned away at the Jeep Jamboree for the rubicon trail. They have a requirement now that you have to have a minimum of 37’s.

He wrote Jeepers Jamboree, not Jeep Jamboree. They are different.

 

[steelhd]

... (based on Grim Jeeper) ...

In summary, I want to know if I'm crazy wanting to go with 5.13 gears and ARB lockers in my non-Rubicon TJ (4.0L, 42RLE, NP231, 33" tires)?

You arent crazy, you used Grim Jeeper to do your homework based on comparisons against your current setup and deciced what you want for how you use your Jeep.

 

[Claytone]

It’s a common thing for folks the get wound up about low gear ratios. My lifetime hot rodder buddy thought I was crazy for going to 4.56 with my setup till I showed him the numbers.

 

[jjvw]

5.13 is the best you can do for 33s and the 42rle with your axles.

As far as lockers, I have had no problems with my ARB. Eaton is probably fine, too.

 

[L J]

Also, I was thinking 5.13 gears for my 4.0L with 42RLE and 33" tires (based on Grim Jeeper).

you are correct

The guy at the local shop is saying that's overkill and that 4.10 would be plenty,

We see it all the time with guys reporting what a shop told them. Either the shop doesn't know the 42rle or they are stuck in old thinking.

 

[Jodh]

OP sent you a PM about new axles for sale.

 

[ClayAkers]

UPDATE: Just got the Jeep back from the shop on Saturday and here's the final build:
5.13 Yukon gears
30-spline, G2 chromoly axles front and rear
ARB air lockers front and rear
ARB CKMA12 compressor
ARB diff covers

I can't believe how much better (and quieter) it rides and drives. It's like a brand new vehicle. And, while it was certainly very capable off road before, it does so much more now. Can't wait to get it on the Rubicon in a month!

 

[cpwolf]

UPDATE: Just got the Jeep back from the shop on Saturday and here's the final build:
5.13 Yukon gears
30-spline, G2 chromoly axles front and rear
ARB air lockers front and rear
ARB CKMA12 compressor
ARB diff covers

I can't believe how much better (and quieter) it rides and drives. It's like a brand new vehicle. And, while it was certainly very capable off road before, it does so much more now. Can't wait to get it on the Rubicon in a month!

You are familiar with Hidden Falls Adventure Park out on 1431 just outside of Marble Falls right? It's not the Rubicon Trail, but if you want to see how your new setup is going to go, it's a good time...and they have a full competitive skeet range there too, so fun all weekend, ha.