Hey guys I have had my TJ for a little over a year now and I’m really starting to get into modifying the rig, Looking to re gear and add a selectable locker very soon and looking for some input. As of right now I have Dana 30/Dana 44 axles with stock 3:73 gears in em, rolling on 35” rubbers and a 42rle auto. What is the best gear to go with for my current setup? Again this is a daily driver mostly around town with occasional highway trips to go up north or to the trails. Also locker preference ARB? Eaton E locker? Yukon? Looking for pros and cons between air and electric selectables. Thanks.
Re-gearing advice for 35s, 42RLE transmission, and lockers
- Thread starter Ryan
- Start date
Ideally you'd put in 5.38 gears, but the deepest you can go with that Dana 30 is 5.13, so that's what you'll be stuck with.
I have 5.38 gears in my Rubicon with 35s and the 42RLE, and it's perfect. 5.13 will be close enough!
As for lockers, if you plan on driving it on-road, I highly recommend a selectable locker. Either ARB or Eaton E-Lockers, one or the other.
They've both been proven. If you plan on running on-board air, then the ARB makes more sense. If you don't plan on running on-board air, you might want to go with the E-locker, but again, they are both excellent choices.
I have 5.38 gears in my Rubicon with 35s and the 42RLE, and it's perfect. 5.13 will be close enough!
As for lockers, if you plan on driving it on-road, I highly recommend a selectable locker. Either ARB or Eaton E-Lockers, one or the other.
They've both been proven. If you plan on running on-board air, then the ARB makes more sense. If you don't plan on running on-board air, you might want to go with the E-locker, but again, they are both excellent choices.
X2 on doing the lockers at the same time. You will have to pay for it twice if you do the lockers separately from the gears.
As @Chris noted, 5.38 is the most appropriate axle ratio for the 42RLE transmission mated with 35" tires but 5.13 is the deepest ratio available for your Dana 30 front axle so that is your best choice.
There are pros and cons to air activated vs. electrically activated lockers. If you already have or intend to install an onboard air system then ARB air lockers are the logical choice.
I like the concept of electric lockers (less plumbing, no air storage needed), but there are reports of a slight lag in engagement with Eaton lockers because one must roll forward a few feet before the locker engages. However, I would not let those reports dissuade me from installing one. I have experience with a factory electric rear locker in another 4WD vehicle I own and the very slight lag in engagement is easily compensated for by not waiting until one is already in trouble or stuck before turning it on.
There are pros and cons to air activated vs. electrically activated lockers. If you already have or intend to install an onboard air system then ARB air lockers are the logical choice.
I like the concept of electric lockers (less plumbing, no air storage needed), but there are reports of a slight lag in engagement with Eaton lockers because one must roll forward a few feet before the locker engages. However, I would not let those reports dissuade me from installing one. I have experience with a factory electric rear locker in another 4WD vehicle I own and the very slight lag in engagement is easily compensated for by not waiting until one is already in trouble or stuck before turning it on.
I would always have a locker on when off-road, so the slight lag time for an e-locker is irrelevant. I agree with @Mr. Bills 100%
Agreed on the 5.13 recommendation, don't let some clueless shop yahoo talk you into 4.88 which would just cause the engine to lug with 35" tires... personal experience there. I'd recommend 5.38 except your Dana 30 can only go to 5.13, as said above.
If you can afford ARB, that's definitely the way I'd go. Just make sure the shop you choose to install them has lots of experience installing them. They require expertise and a shop that has plenty of experience with other lockers but insufficient experience with ARB would not be a good choice.
If you can afford ARB, that's definitely the way I'd go. Just make sure the shop you choose to install them has lots of experience installing them. They require expertise and a shop that has plenty of experience with other lockers but insufficient experience with ARB would not be a good choice.
Not quite enough rpms but it's better than it would be with 4.88. I'm running 5.38 with 35's and at 70 mph it's right at 2600-2650. I'd rather it was 2700-2750 like I had when I was running my previous 5-speed with 4.88 and 35" tires.
5.13 is barely even adequate for 35's when you have the 42RLE transmission. I'd be recommending 5.38 for you if your front axle wasn't a Dana 30 that can't be geared any lower than 5.13.
Joemac
New Member
Ryan,
I need some first-hand advice. What did you decide to do with your rig? I plan on similar use as you (but I’m in Texas) mainly flat land, road driving, some highway (60-70mph), maybe a summer trip to TX hill country, Colorado mountain trails. I have a 2006 LJ (non Rubi) w/ 42RLE, Dana 30/44, running 315/70-17’s (34.5”). I took advice of websites & axle shop & regeared to 4.56; its terrible & $2k wasted.
What did you go with? 35’s & 5.13’s? How does she do on road? How are RPM’s? Is it too low/loose starting on wet/slick pavement? (Don’t want it squirrelly if my kid is driving). How is it off-road in low gears? ANY advice greatly appreciated.
4.56 is a terrible choice for that setup.
You should be running 5.13 gears and nothing else.
Didn't somebody recently post that revolution or some other brand was making a 5.36 for the dana 30?
If they are, it's news to me! If that is the case, then that is undoubtedly the gear he should be running over 5.13. I just say 5.13, because to my knowledge that is as deep as you can go with that Dana 30, unless Revolution just announced that game changer.
The deepest you can re-gear your rig with its current Dana 40/44 axle assemblies is 5.13:1. That is the ratio you should choose.
My first hand experience is this:
When I purchased my LJ Rubicon with 42RLE transmission and "metric 35" tires (34.5") it had 4.88 gears. Performance was sluggish and overdrive was nearly useless.
During my gear ratio decision-making process I drove my gear installer's jeep, equipped identically to yours with Dana 30/44 axles, 4.0, 42RLE transmission, 34.5" tires, but with 5.13 gears. The gearing was much better, but I was still manually shifting out of OD more than I liked so I knew 5.38 would be a better choice for me.
I re-geared to 5.38 and never looked back. The ratio keeps the engine in its power band which makes it more responsive and more efficient. Just last weekend I did a 600 mile trip that included quite a bit of twisty 2-lane mountain road and many hours of Interstate driving at 75 mph on flat land. It reaffirmed my gear ratio decision.
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Note: If it is correct that there are vendors now offering 5.38 gear sets that fit a non-Rubicon TJ Dana 30, then the 5.38 ratio is what I would recommend over 5.13. However, if there are no such gear sets and 5.13 is as deep as you can go I wouldn't lose sleep over it.
Joemac
New Member
@Ryan,
I need some first-hand advice. What did you decide to do with your rig? I plan on similar use as you (but I’m in Texas) mainly flat land, road driving, some highway (60-70mph), maybe a summer trip to TX hill country, Colorado mountain trails. I have a 2006 LJ w/ 42RLE, Dana 30/44, running 315/70-17’s (34.5”). I took advice of websites & axle shop & regeared to 4.56; its terrible & $2k wasted.
What did you go with? 35’s & 5.13’s? How does she do on road? How are RPM’s? Is it too low/loose starting on wet/slick pavement? (Don’t want it squirrelly if my kid is driving). How is it off-road in low gears? ANY advice greatly appreciated.
Thanks for the advice guys. Mr. Bill, correct me if I’m wrong but I think the rubi t-case is geared different? Mine’s non-Rubicon. I’d love some feed back on my above driveability questions from @Ryan or someone with the same 42RLE transmission, t-case & 5.13 gears.
You stand corrected. The transfer case low range ratio is irrelevant to the axle re-gearing analysis for everything except perhaps a dedicated trail-only rig. You want to base your axle gearing on the top transmission gear ratio and the tire size in high range, which is 1:1 for both the NV231 and NV241OR. In your case the only numbers you need are the 0.69:1 OD ratio of the 42RLE and your "metric 35" tires. If this doesn't make sense try using the Grimm Jeeper calculator inputting the 231 transfer case and again inputting the 241 and you will see that it makes no difference on the highway.
Also, in Post #17 I did provide you with first hand experience of the driveability of the 4.0/42RLE/5.13/metric 35 combination in my gear installer's personal jeep. Even though the transfer case low range ratio is irrelevant, please note that my gear installer's jeep is a non-Rubicon with the same transfer case as yours evidenced by the Dana 30/44 axles, hence the 5.13 gears.
Mr. Bills said:
The bottom line is that 5.13 will be the most frequently recommended ratio for your jeep, or 5.38 if in fact there is now a supplier for that ratio in the TJ Dana 30.