Gearing.. How much of a seat-of-the-pants difference does it really make?

[TwelveGaugeSage]

It's largely the high speed desert running guys saying that. They max out top speed for 4 low on a Rubicon. Since we have nothing similar around my region of the east coast, I can't imagine running out of gear in 4L, but those that run out west do. That's why jeep gave them the Mojave.

My first thought is, well why not just use 4-hi, but I guess there are a few benefits to 4-low and having quick access to shorter gearing without hitting the T-case lever. I did a lot of rock crawling in Arizona, but never high speed off-roading. 4-low 1st gear can't be too short for me, lol. I love having a nice short 1st on an off-road motorcycle too. I wish my WR250R had a granny first.

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[Wheelin98TJ]

It’s all relative and should be need based. you gain faster acceleration and you may hold 8th gear longer but your 8th gear will be spinning at 3K RPMs vs 2K so why not just rock 6th at 3K and save the money if not towing ?

p.s. made up those RPMs for illustrative purposes

Less downshifting after a regear. Trans will run cooler.

Also, you keep all 8 speeds instead of turning your 8 speed into a 6 speed.

 

[Wildlifeguy]

Good comments. I'm just going to have to find a way to try it or bite the bullet and get it done knowing I won't be disappointed.
Regarding the low being too short: I have a scrambler that lives on a ranch as a hunting vehicle. Now it has a gearing problem with 2.73 axle ratio. It won't make even small hills in high gear unless I have some speed which can't happen on rough rocky terrain. It is also not nearly as easy to get it in and out of low as these new ones. I just keep it in 4L most of the time. The problem is on the one flat gravel road, I'm usually in 4th or 5th gear to keep the rpms from screaming at 2800 (that feels really high in the old 4.2's). In this case, a 4:1 transfer case gearing would probably be too low for me. However, I also have a couple of fairly steep rock climbs that first gear is a little too high and I have to go faster than comfortable. In this case, an axle ratio of 3.73 or 4.1 with transfer caseof 2.72 would probably be perfect for my needs and allow me to use high range 90% of the time and 4L as needed. Since I don't need the low as often, a 4:1 would probably be great. I know this is not the same as our new ones, but just some perspective. I can see on sand the 4:1 TC ratio in the JT may be too low trying to keep up some speed.

 

[DC3]

I just went through this same debate and did 4.56. At first, I was a little let down but I am glad I did and I think I will continue to appreciate the change over time. It was not a dramatic night and day difference. More of a "this makes a good thing better" difference.

My post on the topic

 

[hjdca]

I've read and read, I know the numbers and what they mean. I'm not really concerned about what ratio to go to. I really want to know how big of a difference you actually feel when going lower gears. Currently I have 35s on stock 3.73 gears. I bought it that way new off the lot and never drove one with stock size tires. I came from an ecoboost F150 with the 6 speed. I was used to it hitting top gear soon and set the cruise at 75 and it would not drop down a gear unless I was going up a mountain. It had a massive amount of low end torque. I've now had the gladiator for 5 months and around 6k miles. It feels adequate. On flat ground and no wind, it will cruise in 7th and occasionally 8th. Any hill and it's 6th or 5th. Against the wind, it wont go higher than 6th.. Passing on the highway seems perfectly fine to me. Off the line if just fine. Between 20-50 it feels a little sluggish.

Without considering any other driving conditions or future changes, how much difference would I feel going up to something like 4.56? Is this a night and day difference or just better? I wish I could find someone who has regeared take a ride with them to really feel the difference. Just trying to determine if I should prioritize this change.

I went with 5:13s and light 37" tires and rims (Goodyear Kevlar) on a 6 speed stick Rubicon and I am super, super happy. The best part about the gear change is the acceleration of the lower gears. My truck is really quick and can beat V8s from stop light to stop light - especially if I row the stick aggressively... - I am gone. Everybody talks about the fwy RPM, but, the real benefit for going to 4:88 or 5:13 is the torque multiplication and the acceleration of the lower gears. In addition, I do not have to be in 4Lo all the time when I am 4wheeling. 4Wheel high 1st gear is much more usable. 4Wheel low, 1st gear is also better for Rock Crawling. You can never have too low a 1st gear granny gear. IMHO, I would go minimum 4:88s, the fwy mileage will not make a difference between 4:56, and you will get better acceleration. 4:88s or 5:13s will be a night and day difference with acceleration.

 

[Aonarch]

The fact that you rarely hit 8th gear should make you think about a regear.

Your trans and mpg will thank you.

 

[Ted Striker]

The fact that you rarely hit 8th gear should make you think about a regear.

Your trans and mpg will thank you.

My thoughts as well. When I had my 37's installed on my Texas Trail with 3.73 gears, I would occasionally hit 8th gear on the highway unless it was completely flat and no wind. That's even with the Tazer updated to reflect the tire size change. Every little hill, it was dropping down into 7th or 6th even. Now that I've re-geared to 5.13, it pretty much stays in 8th while cruising and RPMs are around 2200-2300, again with the Tazer updated to reflect the gear change. To me, it was a huge difference.

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