What Gearing Should I Get?

[joshrude]

Regearing: I am currently running 33s with 3.45 gearing. I plan on getting 35s and a regear soon. So the question is do I get 4.88s or 5:13s? I have the manual transmission.

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[rustyshakelford]

4.88s with the 6 speed and 35s. Highway rpm would be really high on the highway with 5.13s. There would be a ton of power however but the noise and reduced mileage wouldn’t be ideal.

Brett

 

[scrape]

Rubi T-case first, gears later.

 

[ChattVol]

Regearing: I am currently running 33s with 3.45 gearing. I plan on getting 35s and a regear soon. So the question is do I get 4.88s or 5:13s? I have the manual transmission.

Most importantly...how do you use your jeep? Daily driver on the highway alot? How often do you wheel it? What type of terrain do you wheel?

 

[D60]

Most importantly...how do you use your jeep? Daily driver on the highway alot? How often do you wheel it? What type of terrain do you wheel?

This. And at what altitude do you normally operate? Here in Colo 5.13 would not be unreasonable. These engines like to spin anyway and the tiny drop in MPG would be worth it

 

[rustyshakelford]

Rubi T-case first, gears later.

I wouldn’t suggest this with the manual. They are much different than the auto and can’t compensate like the 8 speed. The t-case won’t help on the road at all. With a regear, the 2.72:1 t-case is respectable, obviously a 4:1 would be best but that’s a benefit you’ll only appreciate when you’re wheeling in 4LO

Brett

 

[Krondor]

I'm still looking at getting 4.88 next year and I'm running 315/70R17 with a manual. To keep stock ratios I'd actually only need a bit less than 4.56, so be careful how deep you go as has already been mentioned.

I do drive in Colorado and spend a bit of time roaming back and forth on pavement.

Here is another useful thread:

https://www.jlwranglerforums.com/forum/threads/gearing-calculator.38206/

 

[rustyshakelford]

I'm still looking at getting 4.88 next year and I'm running 315/70R17 with a manual. To keep stock ratios I'd actually only need a bit less than 4.56, so be careful how deep you go as has already been mentioned.

I do drive in Colorado and spend a bit of time roaming back and forth on pavement.

Here is another useful thread:

https://www.jlwranglerforums.com/forum/threads/gearing-calculator.38206/

Folks think getting gearing back to stock is ideal. I tend to disagree. Stock the jeeps are adequate. When you lift them, remove what little aerodynamic features they have, add big and heavy wheel/tire combinations you are going to need more power at a given speed. As your speed increases, the need for more power drastically goes up as well. These Jeeps aren’t really big power producers and like being a little higher in the powerband. What I’m curious about is how well the diesel handles the big tires on stock gears. It might be able to compensate really well. I love an auto with 37s to be running 5.13s, 40s do great with 5.38s. 4.88 is about the minimum I’d install on anything that’s not running stock tires.

Brett

 

[D60]

Keeping stock ratios is over-rated in many cases. You're not accounting for reduced aerodynamics due to an overall increase in ride height, increased mass of larger tires and aftermarket wheels, and any gear you might add to or bolt on the vehicle.

Going at least a little deeper than stock is VERY reasonable, so if the math tells you 4.56 then 4.88 is a good call.

If you drive on the highway A LOT and MPG is incredibly important to you, then maybe less gear is ok if you're trying to keep your RPM's down, but again the vehicle will be fighting more wind and likely handling more weight so it may simply use 8th a lot less, in which case you might as well have gone a little deeper in the diffs, anyhow.

I personally don't understand buying a Wrangler to be a gas saver and these little engines that put out more HP than torque can only benefit from gear reduction. But a normally aspirated engine will perform differently at sea level vs 11k' so if you're driving across TX mostly it's way different. I live at 6700 and in 3 of 4 of the cardinal directions I have to go UP first just to get out of town....8k to the West, 10k to the East and 11k to the North.

I'd go 5.13 then you're ready for 37/38's which is inevitable

I drove a Ford 351W all over the country spinning ~2700 at 70mph so if a little V6 wants to hold 3k on the highway I just don't see that as a problem.........plus these new engines are WAY more free-revving than the old V8 architecture. Of course after paying for gas at ~11mpg everything else seems like a gas saver!

That's just me - YMMV literally

 

[D60]

Folks think getting gearing back to stock is ideal. I tend to disagree. Stock the jeeps are adequate. When you lift them, remove what little aerodynamic features they have, add big and heavy wheel/tire combinations you are going to need more power at a given speed. As your speed increases, the need for more power drastically goes up as well. These Jeeps aren’t really big power producers and like being a little higher in the powerband. What I’m curious about is how well the diesel handles the big tires on stock gears. It might be able to compensate really well. I love an auto with 37s to be running 5.13s, 40s do great with 5.38s. 4.88 is about the minimum I’d install on anything that’s not running stock tires.

Brett

Plus if you're starting with a Rubi (which I believe the OP is not), it's laughable to open up the diffs and go to all the work and expense (even if you DIY the parts ain't cheap) of a swap to go 4.10 to 4.56. It's not even worth the time until you start talking 4.88, at which point the relatively small jump to 5.13 just makes more sense IMO. Starting with a Sport at 3.45 muddies the waters a bit.

 

[joshrude]

4.88s with the 6 speed and 35s. Highway rpm would be really high on the highway with 5.13s. There would be a ton of power however but the noise and reduced mileage wouldn’t be ideal.

Brett

That's exactly what I was thinking. But I do go wheeling fairly often and will *eventually* go to 37s.

 

[scrape]

I wouldn’t suggest this with the manual. They are much different than the auto and can’t compensate like the 8 speed. The t-case won’t help on the road at all. With a regear, the 2.72:1 t-case is respectable, obviously a 4:1 would be best but that’s a benefit you’ll only appreciate when you’re wheeling in 4LO

Brett

Off road is where a manual needs gearing the most. Even JKs with 3.21s and a higher 1st gear are perfectly streetable with 35s. But off road they are a mess.

Unless you want to personally regear this guy for 1k OTD then I would seriously think about the value proposition of throwing money into sport axles.

Deals like this are out there, and then when everyone else realizes you can buy rubi axles for 4500 brand new from the dealership, the used take off market will come down.

 

[rustyshakelford]

Off road is where a manual needs gearing the most. Even JKs with 3.21s and a higher 1st gear are perfectly streetable with 35s. But off road they are a mess.

Unless you want to personally regear this guy for 1k OTD then I would seriously think about the value proposition of throwing money into sport axles.

Deals like this are out there, and then when everyone else realizes you can buy rubi axles for 4500 brand new from the dealership, the used take off market will come down.

For a customer we work with I never suggest regearing a sport axle. Rubi takeoffs are always my first stop. This guy was asking about ratios. The drivability of a manual with larger tires is terrible, even worse when you have a sport or sahara. Since 99% of jeeps spend 99% on the road the gears in either axle are more beneficial than a tc. Even a 4:1 tc with 35/37 and 3.45 gears isn’t great by any stretch. Considering a take out tc is around 1500 plus labor to install I still wouldn’t suggest that unless the customer was adamant about their time off road. Even then we’re asking for issues with the current set up. For the op, they can spend 2k on gears and get the drivability back.

Brett

 

[scrape]

For a customer we work with I never suggest regearing a sport axle. Rubi takeoffs are always my first stop. This guy was asking about ratios. The drivability of a manual with larger tires is terrible, even worse when you have a sport or sahara. Since 99% of jeeps spend 99% on the road the gears in either axle are more beneficial than a tc. Even a 4:1 tc with 35/37 and 3.45 gears isn’t great by any stretch. Considering a take out tc is around 1500 plus labor to install I still wouldn’t suggest that unless the customer was adamant about their time off road. Even then we’re asking for issues with the current set up. For the op, they can spend 2k on gears and get the drivability back.

Brett

That’s fair, it really comes down to one’s subjective preference on what is “good driveability” and what is not. 35s on a sport might mean you lose 6th gear but it still drives just fine if you pretend it is a 5 speed with slightly taller gears. That’s my opinion though, I know some people are pretty anal about being able to use every gear like stock.

The way I look at it is, I’ve never had anyone ever come back to me and tell me that they regret a deeper Tcase in a manual rig. I’ve had plenty of people tell me they regret putting money into their stock axles.

If you want to wheel a manual rig with 35”+ tires in any serious fashion you are going to want both a Tcase and deeper axle gears. So my recommendation is always to do the Tcase first because it is way more future proof. Then when you figure out exactly which direction you want to go with your build as far as axles/lockers, you can do everything at the same time and avoid wasting money.

Just my opinion, and if nothing else, something to consider and rule out.

 

[Az-jewel]

This has been very helpful!!
I have a 6-speed Sport with 35’s on the Mooar lift. It’s been rough, especially wheeling it! Steep inclines and rocks are extra challenging with NO power!! In 4lo in 2nd gear I can usually get up a steep rock without stalling. But I sacrifice some control because I need to be on the gas too much to crawl up. I am going to 4.88 next week and can.not.wait!!!

I debated 5.13 as I may eventually go to 37’s, but was thinking the 4:1 transfer case would help if I did that? Eventually I want lockers, but for now the e-brake and LSD are doing ok.

I priced getting it all done now, and just can’t swing it. Regearing will be most impactful for me so I’m doing it first.
I have been out off roading 2-3 times a week lately with our gorgeous AZ weather and this confinement.

I will probably swap out the front axle (might truss it, but probably not) and add lockers and the transfer case down the road.

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