• Want to add an app icon for this forum to your mobile device's home screen? Check out this thread to see how.
  • Have an event you want to share? Check out the new forum event calendar and how-to use it in this thread here.
  • To both new members and existing members, please read this thread about posting your topics in the correct sub-forum. It makes my job (and my life) a lot easier!

Upgrade Decisions: Re-gear, axles, and lockers

Rick2004LJ

Member
Joined
Jun 11, 2018
Messages
56
Location
Texas
All of the following questions have probably been answered in other threads, but my search skills are lacking and I couldn't find anywhere my specific situation was addressed. Also let me know if this is better suited for the "How To" or "Resources" forums.

We are ready to do some upgrades to our trail rig to increase crawling capabilities. My original plan was to run what I have until I broke an axle or something else that forced me to dive into the gears and axles, but try as I might they have held together and I figure my luck is running out. Problem is I don’t have unlimited $$ so looking for a little advice on the options I am looking at and order of importance for our use.

Our Jeep is a dedicated trail rig that we trailer to destinations - only road use is short stints between trails etc. We mainly do rock crawling/obstacles (not a fan of mud/water/sand) and as we have gained experience we have really started pushing the Jeep (and our abilities) on harder trails/obstacles. Have worked up to Jeep Jamboree trail Ratings of 7 and up, going as hard as the trail guides will let me or tell me I have a chance to make it. We do 5-7 Jeep Jamborees a year plus other off-road parks and are headed to Moab spring break next year.

Rig - 2004 LJ (Not Rubicon), 42RLE Auto Trans, 4" suspension lift, stock axles D30F D44R with 3.73 ratio, Truetrac's front and rear, currently running 33" tires but will go to 35"s when current tires wear out.

Upgrades we are considering:
Axles & Re-Gear - The goal is purely trail capabilities - don’t care about RPM's/power for 65 MPH on the highway. We love the Auto Trans for crawling (we started in a JK 6 spd manual) but I really miss the control of 4WLo crawl speed (up & down slopes) we had with the stick. The most recommended upgrade is chromoly shafts and re-gear to 4.88 or 5.13. Another option is a Rubicrawler but have seen mixed info on how well it works on a non-Rubicon setup? Based on the above could I get away with the Rubicrawler as opposed to re-gear, and would it save me any $?

Lockers - Currently have Truetrac's F&R and they have served us well with only a few times/obstacles where I felt true lockers would have made things easier or allowed us to make an obstacle. But I do know that the harder we push it the more true lockers will be required. Several Questions:
If I can only afford true lockers on 1 axle do I go Front or Rear?
Since it is a pure trail rig can I get away with Automatic lockers (lunchbox, Aussie, etc.) - if so in both axles or just F or R?
Do selectable lockers provide a performance/capability upgrade, over automatics, that are worth the extra $$?
Does it make any sense to mix an Auto in 1 axle selectable in the other and if so, would it save me enough $$ to make a difference?

Are there any other "affordable" alternatives that could achieve both upgrades - like swapping out the stock axles with used Rubicon axles? Any other options?

I know that is a lot of words to wade through, but any info/advice would be greatly appreciated!
 

Jerry Bransford

TJ Guru
Supporting Member
Joined
Nov 9, 2015
Messages
12,546
Location
Escondido California
The first thing I suggest is to regear to 5.13. I'd suggest 5.38 for your future 35's but your front Dana 30 axle only goes to 5.13. Then, since you are doing and like doing rock crawling, I would swap those Truetracs for true lockers. Truetracs are NOT lockers and Truetracs do NOT work well (or work at all) on tougher rock crawling trails. Not... at... all. Once you get one of the tires on a Truetrac equipped axle off the ground it stops working and the tire in the air will just spin, even if you use the best possible braking techniques widely recommended to help a LSD/Truetrac "hook up" better. I finally had to give up on my Truetracs, they just weren't helping on my rock crawling trails. If you replace the f/r Truetracs with actual lockers, as I did on my previous TJ, it will make a DRAMATIC (!!!!!) improvement in how well your Jeep does on rock crawling trails. DRAMATIC!!!!
 

Mr. Bills

TJ Addict
Joined
Nov 24, 2017
Messages
2,111
Location
Area Code 530
Speaking from the perspective of someone who owns an LJ Rubicon with 42RLE auto trans, Rubicrawler, 5.38 gears and 35" tires:

1. The Rubicrawler provides more options with the Rubicon NV241OR transfer case than with the non-Rubicon transfer case. Put it toward the bottom of your list after the other modifications. It is not a substitute for a re-gear.

2. The deepest gears you can run with your Dana 30 front axle are 5.13, so that is what you will want for your planned 35" tires.

3. A lunchbox locker in front and Detroit in the rear will work very well, but "switchable" lockers are very convenient - consider ARB or an Eaton electric locker.

4. The common wisdom is to add the rear locker first, but there is a school of thought that if one is only going to run one locker then it should be in the front. That same school of thought advocates rear lockers that can be switched off in order to run the front locker only. Based on the wheeling you describe, i.e., active participation in jamboree type events, you can go either direction but the "common wisdom" should work out just fine for you. I ran a Detroit/rear with Lockrite/front in one of my previous jeeps. I really liked that combination, but there were times that I wished I could turn the Lockrite off, so a switchable locker in front with Detroit in the rear could be a good combination for you.

5. Chromoly axle shafts are a natural upgrade at the same time as the re-gear, particularly if you are paying a shop to do the labor on the gears (which you should rather than DIY).

6. A brake upgrade should be toward the top of your list - I run the Black Magic/Vanco 16" Big Brake Kit on my LJ, worth every nickle.
 
Last edited:
  • Like
Reactions: taylormade73
OP
R

Rick2004LJ

Member
Joined
Jun 11, 2018
Messages
56
Location
Texas
Speaking from the perspective of someone who owns an LJ with 42RLE auto trans, Rubicrawler, 5.38 gears and 35" tires:

1. The Rubicrawler provides more options with the Rubicon NV241OR transfer case than with the non-Rubicon transfer case. Put it toward the bottom of your list after the other modifications. It is not a substitute for a re-gear.

2. The deepest gears you can run with your Dana 30 front axle are 5.13, so that is what you will want for your planned 35" tires.

3. A lunchbox locker in front and Detroit in the rear will work very well, but "switchable" lockers are very convenient - consider ARB or an Eaton electric locker.

4. The common wisdom is to add the rear locker first, but there is a school of thought that if one is only going to run one locker then it should be in the front. That same school of thought advocates rear lockers that can be switched off in order to run the front locker only. Based on the wheeling you describe, i.e., active participation in jamboree type events, you can go either direction but the "common wisdom" should work out just fine for you. I ran a Detroit/rear with Lockrite/front in one of my previous jeeps. I really liked that combination, but there were times that I wished I could turn the Lockrite off, so a switchable locker in front with Detroit in the rear could be a good combination for you.

5. Chromoly axle shafts are a natural upgrade at the same time as the re-gear, particularly if you are paying a shop to do the labor on the gears (which you should rather than DIY).

6. A brake upgrade should be toward the top of your list - I run the Black Magic/Vanco 16" Big Brake Kit on my LJ, worth every nickle.
Thanks for the great input! I am a little ignorant on the different lockers/brands etc. - are both the Detroit and Lockrite you describe an "automatic locker? Is there any difference in the way they work?
Also good info on the brakes and I have heard this from many folks, just wish I had got the message before I redid mine. I replaced the stock brakes with new regular calipers/rotors/pads from Black Magic. Made a HUGE difference over stock but wish I had gone with the Big Brake kit.....
 

Steel City 06

TJ Addict
Joined
Mar 12, 2019
Messages
1,523
Location
Pittsburgh, PA
Do your regears and lockers at the same time. When lockers are installed, the gears must be set up again. So the cost of putting in gears at the same time as the lockers vs lockers alone is pretty much the cost of the ring and pinions themselves. Doing them separately is going to cost you on the order of an extra 1k in labor in the long run.

Personally if I didn't have a Rubicon I would go with Eaton Elocker4 (4-pinion e-lockers) due to the ease of installation over air lockers. My 2nd choice would be an air locker like an ARB.

Go straight to 5.13, especially if you plan to go with 35s.
 

Irun

Member
Supporting Member
Joined
Oct 31, 2019
Messages
90
Location
Virginia
As has been said, go gears, shafts and selectable lockers first. If possible, the best time to do all this is when you re-gear, because everything will be out anyway. If you can't afford to do it all at the same time, ask yourself these two questions:

Can I wait until I have the funds to do all three at the same time?
If I can't wait, because I need gears, am I willing to spend more money to do it in stages?

As for the option of looking for Rubicon rears, these are getting harder to find, costly to acquire, and will likely require work and money. Having been down this path, your 30/44 combo will hold up fine to 35"tires, provided you upgrade them.

Lastly, as was also stated, skip the Rubicrawler for now. I have one in my '04 LJ, but the real benefit of having it is when it's mated to a 241OR transfer case.
 
Last edited:

AndyG

TJ Expert
Supporting Member
Joined
Jul 30, 2018
Messages
4,350
Location
Alabama
The first thing I suggest is to regear to 5.13. I'd suggest 5.38 for your future 35's but your front Dana 30 axle only goes to 5.13. Then, since you are doing and like doing rock crawling, I would swap those Truetracs for true lockers. Truetracs are NOT lockers and Truetracs do NOT work well (or work at all) on tougher rock crawling trails. Not... at... all. Once you get one of the tires on a Truetrac equipped axle off the ground it stops working and the tire in the air will just spin, even if you use the best possible braking techniques widely recommended to help a LSD/Truetrac "hook up" better. I finally had to give up on my Truetracs, they just weren't helping on my rock crawling trails. If you replace the f/r Truetracs with actual lockers, as I did on my previous TJ, it will make a DRAMATIC (!!!!!) improvement in how well your Jeep does on rock crawling trails. DRAMATIC!!!!
This is the man to listen to .
 
OP
R

Rick2004LJ

Member
Joined
Jun 11, 2018
Messages
56
Location
Texas
Thanks for all of the reply's! So if I am hearing y'all correctly (as well as other stuff I have read) -
Axle - Upgrade/sleeve Chromoly axle shafts
Re-gear - do it and go with as high as I can get in my axles which I think is 5.13.
Lockers -
Cheapest option would be put an Auto Locker in the front (Aussie most recommended?) and leave TrueTrac in the back, assuming existing Truetrac will work with new gears (?).
Good option Aussie Auto in the front and a Detroit Auto in the rear.
Better option - Auto Aussie in the front and Selectable in the Rear.
Best - Selectable Front & Rear
Since I really dont need on-board air (not airing down/up regularly) Eaton E-Lockers are the way to go?

Sound right?
 
  • Like
Reactions: Steel City 06

Jerry Bransford

TJ Guru
Supporting Member
Joined
Nov 9, 2015
Messages
12,546
Location
Escondido California
Thanks for all of the reply's! So if I am hearing y'all correctly (as well as other stuff I have read) -
Axle - Upgrade/sleeve Chromoly axle shafts
Re-gear - do it and go with as high as I can get in my axles which I think is 5.13.
Lockers -
Cheapest option would be put an Auto Locker in the front (Aussie most recommended?) and leave TrueTrac in the back, assuming existing Truetrac will work with new gears (?).
Good option Aussie Auto in the front and a Detroit Auto in the rear.
Better option - Auto Aussie in the front and Selectable in the Rear.
Best - Selectable Front & Rear
Since I really dont need on-board air (not airing down/up regularly) Eaton E-Lockers are the way to go?

Sound right?
Sounds about right to me. I'd definitely replace that rear TT with a true locker. If you don't see snow and ice where you wheel I personally would choose a Detroit Locker. If you get into snow and ice I'd go with the Eaton E-Locker. :)
 
  • Like
Reactions: Steel City 06