My review of 5.13 gears with 33's and 42RLE

Strizzo said:
I like my 5.13 gearing. if/when i go to 35s i'll probably go ahead and do the HPTuners adjustments on the shift strategy to help. Hell I'm tempted to do it now so its not always trying to get into overdrive by 50mph. seems like the changes that make it hold onto lower gears longer and be a little more eager to drop a gear go a long ways towards making the driving experience much more satisfying.
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The HPTuners programming made a dramatic change in my 06.
 
NKlekas said:
When I wanted to re-gear with the 42RLE I was shocked at how low people told me to go. @Chris & @Jerry Bransford both claimed it would be the best set up with 33's and "OK" if I wanted to go to 35's in the future. (I am about 50/50 on going to 35's). I chose to listen to these guys and I'm very happy.

I've had 5.13's on my LJ for over a month and the gears have been paired with 33's for about 95% of that time. The previous owner had 32x10.5x16R on before me and the stock gears did very "OK" with that. I daily drive my Jeep and have taken it on a camping trip up to the Triny Mountains in Idaho, a round trip of about 450 Miles. So with daily driving and the trip, I have over 1,000 on the gears and figured id do a review to help people out given the 42RLE is a typical transmission in the later model TJ's.

I'll review aspects of the gears individually and driving experiences:

Daily Driving: My jeep is much more peppy and efficient. I never drove my LJ (Or any TJ) completely stock but it drives much better. Shifts smoother has better MPG and overall seems to like the gears more. It's just more pleasant to drive. The thing that sticks out the most is the fact that at a complete stop and in Drive I have to have my foot on the break because it will crawl on its own. It never did that with the old set up and I'm shocked at the amount of Tourqe I got back from the gears. I know this explanation isn't super detailed but I can't quite explain it...My jeep just drives better, that's all there is to it.

MPG: I'm not that surprised my MPG shot up. Unfortunately, I have a Roof Rack and my RTT on for pretty much the rest of the summer. However, I was able to get one full tank of gas tracked before the rack and tent went on...I track my fuel and with my old set up I averaged about 9.4 MPG (Since I bought it in December) daily driving. I should mention I have a hardtop and since I've owned the Jeep The heater has run about 80% of that time. Anyway, the one tank I tracked with the new gears came out to 14.7 MPG around town, an increase of over 5 Miles per gallon...I honestly think I could have gotten more if I had more tanks to track. I won't say much about my trips MPG because as you can see in the picture...I was pretty loaded down with gear and the wind was brutal on the way home. I averaged about 12.8 MPG with all the gear and my wife. I never took a camping trip like this with the old gears but the trips I did take it on...with no gear, rack, and wife ... it got about the same..slightly worse actually at about 12.2 MPG...So it's still impressive.

RPMs: Yes the RPMs run higher and that's the point. I won't say that much about my daily driving RPMs because where I live... I stay below 40 MPH 70% of the time and below 55 MPH 95% of the time. I rarely pay THAT close attention to them when I drive around town because I don't need to.
However, that's usually not why we re-gear our Jeeps...I posted two pictures from my trip below to give you an example of the RPMs. With all my gear and Jeep being even MORE top-heavy with the RTT I rarely go any faster than about 70-73 MPH. Even without the gear I never go fast than about 75-78 MPH. The first picture is what the RPMs look like at about 72 MPH in 4th (O/D) the second is when it downshifted into 3rd while still going 70. I LOVE the 2700-2800 range it sits at in 4th. Keeping the RPMs high has made it much more efficient and less mind-numbing shifting every 30 seconds.

The O/D Ratio & Shifting: Now, the re-gear doesn't fix the brutal O/D problem the 42RLE has. But, like stated above, it makes it MUCH more tolerable. The gears keep the RPMs higher and it helps with the shifting, performance, and fuel efficiency. I can attest to this pretty honestly given where I live. Nevada is America's most mountainous state and where I live in Elko (NE corner of the state) we sit at about 5,500 feet elevation. (Another reason why I was so picky with my gears). The 5.13s make driving through the hills and passes much more manageable and my jeep doesn't bog down nearly as much when the road gets steep or elevation shoots up. I feel like I have more "get-up" to tung me up the mountain.

Overall: I'm extremely happy I went with 5.13s given how I use my Jeep and where I live. Like Jerry and Chris have said time and time again on here, with the 42RLE and the nature of the 4.0 engine the deeper the gears the better. if you're thinking 5.13 is too much, don't, it's great and I 100% recommend it.

Hope this helps!!

View attachment 333914

View attachment 333916

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Great real-world review on your set-up. Very informative with the RPM and speed numbers. Now I wish someone would do a review of the 4.88 gears on 35s with the NV3550 5spd.
 
akajibio said:
Great real-world review on your set-up. Very informative with the RPM and speed numbers. Now I wish someone would do a review of the 4.88 gears on 35s with the NV3550 5spd.
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I could tell you.
 
Baby goes under the wrench this coming week. Really nervous that vibes are going to be a headache. Hopefully it will be just a matter of adjusting the DS angle, and then readjusting again once I swap over the Springs/Shocks and do the BL/ML.
 
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My vibrations changed depending on if the gas tank is full or close to empty....

There's always:
IMG_9360.webp
IMG_9358.webp
 
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Hasselblad said:
The folks installing it seem more concerned with the shaft RPMs moreso than the possibility of vibrations.
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Harmonic resonance from shaft rpms is a very real phenomena with the 42rle paired with the np241.
 
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Hasselblad said:
The folks installing it seem more concerned with the shaft RPMs moreso than the possibility of vibrations.
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With 33s and 5.13 gears, the front shaft is at or above the critical speed at around 70mph. I thought about aksing tom woods or adams if they'd make a shaft with the Rzeppa joint like the JK/JL have to see if it would improve things, but never got that far into it.
 
Strizzo said:
With 33s and 5.13 gears, the front shaft is at or above the critical speed at around 70mph. I thought about aksing tom woods or adams if they'd make a shaft with the Rzeppa joint like the JK/JL have to see if it would improve things, but never got that far into it.
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The service life of the u-joints are reduced at those rpms and angles. Accept it and deal with it.
 
Picking up the jeep this eve. The shop said during their once over they had ~2500 RPM at 65 MPH and ~2900 at 70.
(Assuming in 4th gear)

I may squeeze the card sooner than later and get 33s on her. Still a little rubber on the 32s, but can swap one to the spare
 
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rasband said:
More reason to convert to manual hubs!
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Very few mention that manual hubs do improve drivability just enough to be noticeable. The Jeep feels a bit more sprightly with the front wheels unlocked and not spinning the driveshaft.

Unfortunately, the rear driveshaft is unaffected. 😉
 
Hasselblad said:
Picking up the jeep this eve. The shop said during their once over they had ~2500 RPM at 65 MPH and ~2900 at 70.
(Assuming in 4th gear)

I may squeeze the card sooner than later and get 33s on her. Still a little rubber on the 32s, but can swap one to the spare
Click to expand...

FWIW, I just swapped tires. I took off the five old Falken WildPeak 33's with 70k miles on them and a little under 10mm of tread left and sold them for $550 on MP. Crazy but there was no less than a dozen people who wanted them. You could be on those 33's sooner than you think.
 
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MikekiM said:
FWIW, I just swapped tires. I took off the five old Falken WildPeak 33's with 70k miles on them and a little under 10mm of tread left and sold them for $550 on MP. Crazy but there was no less than a dozen people who wanted them. You could be on those 33's sooner than you think.
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Trevor, why the surprised face? You could be on 35s sooner than you think! 😉
 
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