Rubicon Re-Gearing Advice

[J.Cain]

Is there anyone local to the Parker, Colorado area that offers regearing for a 2004 Rubicon (I'd be purchasing Revolution gears with master install kit)? I'm thinking 4.56 or 4.88 with 33's (possibly 35's in the future) and NV3550 (unless someone believes a different gearing option would be better). It is not a daily driver just the occasional trip to the mountains and road trip to Nebraska to play in the sand hills. If anyone does regearing or knows of someone who knows their stuff and is willing I'd be interested in speaking with them and helping out to keep costs down. I know may way around Jeeps have done a fair share of work on them over the years but I do not have the knowledge or proper tools for setting up gears and removing/pressing bearings.

Thanks,
Jeremy

 

[Jerry Bransford]

Go for the gear ratio that will fit the tire size you believe you'll end up with. In your case it's sounding like 35's are in your future so I'd definitely go with 4.88 which will still work fine with 33's. It's definitely better to be slightly overgeared than slightly undergeared. I do know of a superb gear guy but he works out of Riverside County CA so that'd be a bit of a drive for you.

 

[RINC]

Go Big Or Go Home. 5.38 R&P

 

[Jerry Bransford]

Go Big Or Go Home. 5.38 R&P

I run 5.38 with my 42RLE and 35's but I wouldn't advise going that deep for the OP's NV3550 and 35" tires.

 

[RINC]

I run 5.38 with my 42RLE and 35's but I wouldn't advise going that deep for the OP's NV3550 and 35" tires.

Forgive me Jerry. I am day drinking.

 

[J.Cain]

I run 5.38 with my 42RLE and 35's but I wouldn't advise going that deep for the OP's NV3550 and 35" tires.

5.38’s is too steep for my use for sure. The Jeep is overkill for my use for sure but I’m wanting to build a reliable rig that is still streetable and able to make a 250mi trip to Nebraska twice a year Spring / Fall trips.

 

[BC Moto]

I have the 4.0l nv3550 and I was on 33s and I would recommend the 4.88s and it was great with 33's

 

[GregBelleville]

Go for the gear ratio that will fit the tire size you believe you'll end up with. In your case it's sounding like 35's are in your future so I'd definitely go with 4.88 which will still work fine with 33's. It's definitely better to be slightly overgeared than slightly undergeared. I do know of a superb gear guy but he works out of Riverside County CA so that'd be a bit of a drive for you.

Jerry who do you recommend in Riverside area for gears if you don't mind me asking?

 

[J.Cain]

I have the 4.0l nv3550 and I was on 33s and I would recommend the 4.88s and it was great with 33's

I appreciate the insight, I must be mindful of our elevation and how that negatively effects overall performance. Sea level 4.10’s would probably be okay but at 5,600’-10,000’ 4.10’s and probably 80hp to the tires is horrible.

 

[Jerry Bransford]

Jerry who do you recommend in Riverside area for gears if you don't mind me asking?

Martin at https://mobilegearinstallers.com/ who is an absolute guru of regearing. He's also usually significantly less costly than what 4x4 shops charge who frequently hire Martin to do their gearing.

 

[MutantNinjaTJ]

Forgive me Jerry. I am day drinking.

You can't drink all day if you don't start early

 

[GregBelleville]

Jerry I think you left out a response to my question

 

[Jerry Bransford]

I appreciate the insight, I must be mindful of our elevation and how that negatively effects overall performance. Sea level 4.10’s would probably be okay but at 5,600’-10,000’ 4.10’s and probably 80hp to the tires is horrible.

Having ignored the advice to go for 4.56 for when I was regearing for 33's over 24 years ago I went with 4.10 instead, I was afraid of the 4.56 street rpms. Stupid, stupid, stupid. I knew within a couple days I had made a big mistake by having only gone with 4.10 as I constantly had to downshift to even go up the mildest of very slight grades in my part of California. And this was with me living at near sea level. That's why I constantly say now that it's far better to be slightly overgeared than even slightly undergeared.

 

[97TJNM]

Forgive me Jerry. I am day drinking.

Now it makes sense why your posts are particularly spicy today!

 

[jjvw]

Daily driver experience here. For 33s you definitely want 4.88. If you will end up with 35s, then you want 5.13.

 

[Jerry Bransford]

Jerry I think you left out a response to my question

Something else beside my answer in the #10 post above? P.S. You make me want to go mix up an Old Fashioned.

 

[jjvw]

I appreciate the insight, I must be mindful of our elevation and how that negatively effects overall performance. Sea level 4.10’s would probably be okay but at 5,600’-10,000’ 4.10’s and probably 80hp to the tires is horrible.

I can't think of a time in the last 150k miles of driving at any elevation, speed or road type where I thought less gearing would somehow be preferable.

 

[jjvw]

Go Big Or Go Home. 5.38 R&P

RPM calculations for a 35" tire...

NV3550/33.875"/4.88=2832rpm @ 75mph
NV3550/33.875"/5.13=2977rpm @ 75mph
NV3550/33.875"/5.38=3122rpm @ 75mph

All of these are lower rpm than a stock TJ with the 3 speed automatic fresh off the assembly line.

 

[GregBelleville]

Something else beside my answer in the #10 post above? P.S. You make me want to go mix up an Old Fashioned.

Thanks Jerry, at first I wasn't seeing your response, just the quote of my post.

I gave Martin a call just now, seems like a very knowledgeable guy, although he was highly wary of my current plan to put a no slip lunchbox in my Dana 30. He basically said I'm definitely going to break something having the front axle locked 100% of the time and was either advocating I go with limited slip in the front or get a selectable locker which I don't want to do due to the cost.

 

[Jerry Bransford]

Thanks Jerry, at first I wasn't seeing your response, just the quote of my post.

I gave Martin a call just now, seems like a very knowledgeable guy, although he was highly wary of my current plan to put a no slip lunchbox in my Dana 30. He basically said I'm definitely going to break something having the front axle locked 100% of the time and was either advocating I go with limited slip in the front or get a selectable locker which I don't want to do due to the cost.

Martin's a gear guru, not a locker guru.

But he's not that far off where it comes to running a front locker on the factory 27 spline carbon steel shafts goes. For 33's or 35's with a front locker, especially with 35's, it's highly advised to upgrade the front shafts to 4340 chromoly. Any kind of locker, whether it's an automatic like the No-Slip or a selectable can still break the axle shaft's ears that hold the u-joints if you're on a tougher trail. Once you do that you can run any kind of front locker you want.

By the way my favorite front lunchbox locker was the No-Slip, it's a great locker. Just upgrade the front axle shafts to 4340 chromoly and you'll be good to go even with 35's and a front locker.

This is what happened to one of the ears on my front shaft after a couple years running the No-Slip and 35's. You can see the ear snapped at the point the arrow it pointing to while running an extremely difficult trail called Sledgehammer. It was ok until that trail.

Once I replaced my front shafts with 4340 chromoly life was good, never another problem with either axle with both axles running non-selectable automatic lockers and chromoly shafts.

If you upgrade to chromoly shafts up front you'll not have any more problems and you will enjoy the No-Slip. I really loved mine, I couldn't even tell it was there until I shifted into 4x4.