4.88 or 5.13 - pulling camper, heavy 37s and steelie wheels

[Rummie]

Help me decide. Here is my particular situation:

2020 Rubicon. Will be on 3 1/2" MC GC lift. 37" Nitto Trail Grapplers. Wheel Vintiques steel smoothies. All the usual winch/recovery gear/tools/extra gas, including a full height rack, etc. We will push the limits of the payload when the camper is back there.

Mostly driven around town with some local highway driving on occasion. Two or three times a year we head out west into the mountains pulling a 3500 lb camper. We hit lots of trails.

We will also be pulling the camper around Florida.

From what I have read 4.88 will get me back to stock. But given the heavy tires/wheels and all the equipment I'm thinking 5.13 may be a better option in my case. Thoughts?

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[Billet Wilson]

4.88 would feel like 1 gear deeper than stock since 4.56 is equivalent to stock. Ive ran 4.88 gears for the past 6 months and Im about to do 5.13s. 4.88 does hold 8th longer, but it still falls out of 8th more frequently than I like. For your use case I would definitely go 5.13s. You would only see around 115 rpms higher which would help when towing, around town, and be worth the slight mpg hit on the few long trips you do take.

 

[LostWoods]

4.88 would feel like 1 gear deeper than stock since 4.56 is equivalent to stock. Ive ran 4.88 gears for the past 6 months and Im about to do 5.13s. 4.88 does hold 8th longer, but it still falls out of 8th more frequently than I like. For your use case I would definitely go 5.13s. You would only see around 115 rpms higher which would help when towing, around town, and be worth the slight mpg hit on the few long trips you do take.

And 4.88/37 is the same as the max tow stock ratios... Personally, that was a sweet spot for a daily driver but if I were knowingly towing on the regular, it's not where I'd want to be. Especially with how deep the OD is on the 8AT, the only reason I'd avoid 5.13s is that I believe they lose a pinion tooth from 4.88 and are therefore weaker.

 

[Billet Wilson]

And 4.88/37 is the same as the max tow stock ratios... Personally, that was a sweet spot for a daily driver but if I were knowingly towing on the regular, it's not where I'd want to be. Especially with how deep the OD is on the 8AT, the only reason I'd avoid 5.13s is that I believe they lose a pinion tooth from 4.88 and are therefore weaker.

I went with 4.88 gears in both my JK & JT because I've always heard 5.13s were weaker. I feel like 4.88 in the JT is still one gear set to high so I dug into this issue. There are TONs of guys running 5.13s who beat the hell out of their Jeeps hard-core rock crawling or pulling heavy loads and they never have an issue. So theoretically 4.88 are stronger but in reality not so much so to be of any concern.

Factory 4.10 gears on 33" tires is equivalent to 4.56 gears on 37" tires. All of my Jeeps have been Rubicons so this is what my comments are based around.

 

[KurtP]

Help me decide. Here is my particular situation:

2020 Rubicon. Will be on 3 1/2" MC GC lift. 37" Nitto Trail Grapplers. Wheel Vintiques steel smoothies. All the usual winch/recovery gear/tools/extra gas, including a full height rack, etc. We will push the limits of the payload when the camper is back there.

Mostly driven around town with some local highway driving on occasion. Two or three times a year we head out west into the mountains pulling a 3500 lb camper. We hit lots of trails.

We will also be pulling the camper around Florida.

From what I have read 4.88 will get me back to stock. But given the heavy tires/wheels and all the equipment I'm thinking 5.13 may be a better option in my case. Thoughts?

5.33 Would be my recommendation.

I think 4.88 brings 37’s to stock ratio. 5.13 is a touch advantage; 5.33 is really gonna help when youre loaded and towing with heavy tires. Imo.

im going 37 and 5.13 and i dont tow.

 

[JTPatriot]

I would do 5.13's. I am running 37's with 4.88's and pull a 3500 lb. camper on occasion. I so wish I would have gone 5.13's originally. Went back and forth on my decision and from what I read at that time it was 4.88. For just over 100 rpm's more I should have done the 5.13's. Feel it would pull better and hold 8th longer when just highway driving no load.

 

[WK2JT]

5.13’s at a minimum. I have 5.13’s on 37’s and wish I had gone 5.38. It’s mostly fine, but the moment you hook-up a trailer or hit the mountains, especially with all the extra weight, you’ll wish you had 5.38’s.

 

[Phljeeper]

I think everyone is asking too much of a gear change. And a 3500 lb camper should not be an issue even with stock 4.10s. Sure 4.88 or 5.13 would be better but I don’t think it will change the game when towing. A supercharger or hemi swap would change the game and the real issue is a lack of torque on the 3.6 engine. For what it’s worth I went 4.88 with 37s and tow a 5,200 lb camper and feel it does relatively well. I haven’t towed with 5.13s to compare but I am not convinced I would notice a difference.

 

[KurtP]

Another thing to consider: ive never once in a truck, car, or motorbike ever heard of someone lamenting that they are turning 100rpm higher than theyd like.

you can find posts all over about people regretting not gearing down enough. It makes a big difference one way and almost no difference the other.

$.02

 

[AustinL911]

With the 8sp? No doubt; 5.13.

 

[LostWoods]

I think everyone is asking too much of a gear change. And a 3500 lb camper should not be an issue even with stock 4.10s. Sure 4.88 or 5.13 would be better but I don’t think it will change the game when towing. A supercharger or hemi swap would change the game and the real issue is a lack of torque on the 3.6 engine. For what it’s worth I went 4.88 with 37s and tow a 5,200 lb camper and feel it does relatively well. I haven’t towed with 5.13s to compare but I am not convinced I would notice a difference.

I mean the whole idea of gearing here is to get into the power band. The power is plentiful in the scope of what this truck was intended to do once you get to it, it's just not there off the line like a V8.

 

[WK2JT]

I think everyone is asking too much of a gear change. And a 3500 lb camper should not be an issue even with stock 4.10s. Sure 4.88 or 5.13 would be better but I don’t think it will change the game when towing. A supercharger or hemi swap would change the game and the real issue is a lack of torque on the 3.6 engine. For what it’s worth I went 4.88 with 37s and tow a 5,200 lb camper and feel it does relatively well. I haven’t towed with 5.13s to compare but I am not convinced I would notice a difference.

I’ve driven a rig with 5.38’s. While not night/day difference, you can tell, especially when pulling hills.

Cost of mods is another thing to consider:
Gear change - Approx $2,500 installed
Supercharger - Approx $8k installed
Hemi swap - just buy a Ram or wait

 

[Trippin01]

So, with all the advice out there, and 99% of it real good. I'm going to go with the 4.88's. I run 34" tires when I pull my trailer and around town, if I'm forced to drive around town, which isn't often (JT is a 3rd vehicle) I run 37's with no trailer when I want to hit MOAB, or Ouray, or other similar trails, and when I have the ultra light RTT on. I just can't see wearing down $350ea 37" tires when I pull the off road trailer. (18' Jayco Baja @ 4k lbs) I have 2 sets of wheels to, so they are matched to the tires. The 34's do look a little whimpy with the 4.5" lift tho. Definitely a 1st world problem. Great thread!

 

[iadslgladiator]

Or you could go diesel, leave everything stock, and not sacrifice anything....., fuel mileage or power/performance. Sorry, couldn't help myself.

I had a gasser (manual 6spd) totally different I know. But with 37x13.50 nittos. It definitely needed 5.13's. just have to get used to your engine turning a lot of rpms and fuel mileage sucking

 

[KurtP]

I ended up going 4.88’s on my 37’s. 4.56 is actually stock eq, 4.88 one deeper, 5.13 two deeper.

I am a sample size of one, and this is just my opinion.

-I dont tow, but if I did id go 5.13.

-4.88 i think is great for my purposes daily driving and overlanding. I also think 4.88 with a blower will be sublime.

As ive gone through these threads here and on JL and seen who is happy or unhappy with what and why, this is my general sense.

How happy people are or arent seems to depend entirely on how accustomed they are to high-cog count transmissions. My 4.88/heavy 37’s with a load holds 8th gear readily. I talk to another Jt owner who tows who says the same. As hills come, depending on a number of factors, it will downshift in accordance with those factors.

I see a lot of people who are unhappy with gears because the truck still downshifts after regear.

I think MOST people on 37’s should go 5.13 or 5.38 because of this. They are used to driving low cog count transmissions, or perhaps engines with much more low end tq. We are neither of these things. 8 and 10 speed transmissions are gonna shift. That’s just the way it is. Those taller cogs are to get you flat cruise efficiency. The method works.

A lot of people seem to want to get to 8th gear and sit there no matter what. To overcome a tall geared transmission, you’re going need to gear super deep to over come those gears and the tires.

Imo, 4.88 is the minimum for 37’s. But i think as C load range 37’s become available, it is going to be an increasingly great option, and it works great for me now. It mixes good acceleration with good economy.

I think a lot of folks need to adjust to high cog transmissions a little more; or if they know they can’t, gear super deep to 5.38.

Just my $.02

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