That 6MT transmission: I really like it!

[Reinen]

I'm kind of a newbie with the gearing ratio. With a strong risk of looking completely stupid, what does it change, exactly?

As others have said, it changes the amount of rotations of the driveshaft to turn the wheel one rotation. On a Jeep, this is primarily done to give the engine more leverage to turn larger tires. A larger tire will move the vehicle further with 1 rotation, so adding larger tires and lowering the gearing ratio will return the engine RPM to Distance/Speed ratio closer to stock.

This isn't the only reason to change the gearing ratio. In contrast, my little brother had a GTO with a lowered gear ratio and stock tire size. This made his 0-60 time insanely fast and he could leave rubber on the road at will in any gear. However, his lowered gear ratio also meant he couldn't go faster than 65-70 on the highway without redlining his RPMs. It was a weird car to drive.

So, hilariously, my old YJ could win a race against his GTO if the distance was long enough and on a highway.

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[JLBoucher]

As others have said, it changes the amount of rotations of the driveshaft to turn the wheel one rotation. On a Jeep, this is primarily done to give the engine more leverage to turn larger tires. A larger tire will move the vehicle further with 1 rotation, so adding larger tires and lowering the gearing ratio will return the engine RPM to Distance/Speed ratio closer to stock.

This isn't the only reason to change the gearing ratio. In contrast, my little brother had a GTO with a lowered gear ratio and stock tire size. This made his 0-60 time insanely fast and he could leave rubber on the road at will in any gear. However, his lowered gear ratio also meant he couldn't go faster than 65-70 on the highway without redlining his RPMs. It was a weird car to drive.

So, hilariously, my old YJ could win a race against his GTO if the distance was long enough and on a highway.

Oh, thank you all.

So let's say i'm good with stock 32s. Should I keep the stock gearing ratio too? Because I really want to keep it as stock as possible. The only mod I really want to do is to put on winch on that thing.

 

[TheKeither]

Oh, thank you all.

So let's say i'm good with stock 32s. Should I keep the stock gearing ratio too? Because I really want to keep it as stock as possible. The only mod I really want to do is to put on winch on that thing.

That is going to be determined in how you like it when you drive it. Its taken me about a month to really understand how to drive my '21 Willy's Sport. I've found 3-3.5k to be optimal revs to shift. On the hilly roads here in Southern PA (Lancaster County), I will hang out between 4th and 5th depending on the road and speed. On the highway, once you're at or over 65 mph, then 6th can actually come to play, but only if you are wanting to maintain speed. You're not going to accelerate AT ALL in 6th, as you are at ~ 1800 rpm @ 70mph.

 

[JLBoucher]

That is going to be determined in how you like it when you drive it. Its taken me about a month to really understand how to drive my '21 Willy's Sport. I've found 3-3.5k to be optimal revs to shift. On the hilly roads here in Southern PA (Lancaster County), I will hang out between 4th and 5th depending on the road and speed. On the highway, once you're at or over 65 mph, then 6th can actually come to play, but only if you are wanting to maintain speed. You're not going to accelerate AT ALL in 6th, as you are at ~ 1800 rpm @ 70mph.

Yes, I've already seen that 5th and 6th are useless to pass anybody. I usually drop to 4th, even 3rd sometimes, if I want to pass somebody quickly. But hey, in 3rd or 4th, that thing goes!...and so does your gas!

 

[TheKeither]

Yes, I've already seen that 5th and 6th are useless to pass anybody. I usually drop to 4th, even 3rd sometimes, if I want to pass somebody quickly. But hey, in 3rd or 4th, that thing goes!...and so does your gas!

I often kind of shake my head when people are complaining about having to shift going up a hill.....

Ummm.....you bought a manual transmission.....IT REQUIRES YOU TO SHIFT!

I'm being flippant I know, and I get their point, but it does make me laugh.

PS - I for some reason didnt realize you already had your 21 Willy's so sorry for "man-splaining" the shifting points!

 

[Reinen]

Oh, thank you all.

So let's say i'm good with stock 32s. Should I keep the stock gearing ratio too? Because I really want to keep it as stock as possible. The only mod I really want to do is to put on winch on that thing.

A Rubicon comes stock with 32s and 4.10:1 gear ratio. That ratio would be "best". But changing the gear ratio isn't a simple swap. So the question is if the gear ratio is "good enough" for you with 32s. For many people it is and doesn't warrant the time & expense of changing the gear ratio.

To give you an idea of what it will feel like with larger tires, imagine your gears changing from gear 1, 2, 3 etc. to gear 1.2, 2.2, 3.2, etc. Certainly driveable but your gears might feel a little higher than they should be. You'll notice it the most in the lowest and highest gears. That makes some people change their gear ratio while others are fine with adapting their shift points.

 

[JLBoucher]

I often kind of shake my head when people are complaining about having to shift going up a hill.....

Ummm.....you bought a manual transmission.....IT REQUIRES YOU TO SHIFT!

I'm being flippant I know, and I get their point, but it does make me laugh.

PS - I for some reason didnt realize you already had your 21 Willy's so sorry for "man-splaining" the shifting points!

I had to shift down uphill with about any car I had so...I don't get the fuss either.

 

[jdubya421]

I had to shift down uphill with about any car I had so...I don't get the fuss either.

And most autos downshift 2 or 3 times when passing someone or or going up a hill that requires a downshift.

 

[omnitonic]

I really love the 6-speed off-road, but the 6-speed with the 3.6 and the standard tall final drive is getting to be a pretty tedious combination on the highway. I never downshifted so much in my life, and I drive 18-wheelers for a living. Hills around here, my big truck can pull in 10th or 11th gear, and my little truck can pull in 6th, but I keep finding myself with semis ramming up my back door in this Jeep. I need to retrain myself to just go to 4th or even 3rd and be done with it. These top two gears are really, really tall, and you need more ass than this thing has to turn them on a grade.

Mind you, I'm still thinking about selling the little truck. Having a big motor with lots of power isn't everything.

 

[DanW]

Hello there, bonjour.

Before ordering, i've read many times that the 6MT transmission was kind of messy or cumbersome to deal with.

Two weeks after delivery, i'm sincerly wondering why these comments were made. That 6MT's just fine! Okay, I admit the 5th and the 6th gear are useless when you're not on the highway. But i'm curious to know why or how some folks didn't like it.

Oh. One negative: no dead pedal is kind of frustrating at the beginning. But I got used to it just fine.

So, if you're one of those who regret that 6MT option, what's the issues you came up with?

Mine has felt great from day 1. No issues. 3.3 years and 46k and I love it like the day I drove it home. No regrets here. In fact, in within a year, my wife is wanting me to order a white Sport for her with.....a manual transmission! I'll lift it with 35's and will throw 4.56 gears in it, which will put the 6th gear ratio into a good place.

 

[jdubya421]

I really love the 6-speed off-road, but the 6-speed with the 3.6 and the standard tall final drive is getting to be a pretty tedious combination on the highway. I never downshifted so much in my life, and I drive 18-wheelers for a living. Hills around here, my big truck can pull in 10th or 11th gear, and my little truck can pull in 6th, but I keep finding myself with semis ramming up my back door in this Jeep. I need to retrain myself to just go to 4th or even 3rd and be done with it. These top two gears are really, really tall, and you need more ass than this thing has to turn them on a grade.

Mind you, I'm still thinking about selling the little truck. Having a big motor with lots of power isn't everything.

You have a willys, what size tires, is it the stock tire size? Because if your gears are matched to your tires this isn't the case. I routinely pass people in 6th and I can drive the 1.5 hours to a nearby city I drive to often in 6th without ever shifting.

 

[omnitonic]

You have a willys, what size tires, is it the stock tire size? Because if your gears are matched to your tires this isn't the case. I routinely pass people in 6th and I can drive the 1.5 hours to a nearby city I drive to often in 6th without ever shifting.

My gears are as matched to my tires as the factory made them.

I spent some time really digging into this. I decided to delete a big glob of calculations, but the bottom line is that at a target speed of 70 mph, the 3.6 isn't making very much torque at the RPM it turns to deliver that road speed through these gears. The solution is to make it turn faster, either by downshifting, or by hitting the bottom faster and speeding up the hill. It probably climbs hills like a scalded dog in 6th gear if you run 80 mph.

My truck's added weight probably cancels the added power, both vehicles happen to have exactly the same diameter tire, and the real deciding factor here is just a 3.73 vs. a 3.45.

I would probably be a lot happier with the way the Jeep performs as a daily driver if I spent the money to swap to 3.73 or 4.10 gears. I have zero interest in doing this, however. I will just have to deal with it some other way. I can go up the hills more slowly, or I can row through a bunch of gears every day.

 

[jdubya421]

My gears are as matched to my tires as the factory made them.

I spent some time really digging into this. I decided to delete a big glob of calculations, but the bottom line is that at a target speed of 70 mph, the 3.6 isn't making very much torque at the RPM it turns to deliver that road speed through these gears. The solution is to make it turn faster, either by downshifting, or by hitting the bottom faster and speeding up the hill. It probably climbs hills like a scalded dog in 6th gear if you run 80 mph.

My truck's added weight probably cancels the added power, both vehicles happen to have exactly the same diameter tire, and the real deciding factor here is just a 3.73 vs. a 3.45.

I would probably be a lot happier with the way the Jeep performs as a daily driver if I spent the money to swap to 3.73 or 4.10 gears. I have zero interest in doing this, however. I will just have to deal with it some other way. I can go up the hills more slowly, or I can row through a bunch of gears every day.

I didn't realize Willys came with 3.45s and 32s. That's fairly under-geared. Looking at 1820rpms at 70mph in 6th, vs 1860 for a sport, or 2123 for a rubi. I drove for over a year with 3.45 gears and 33s and I couldn't stand it, basically left it in 4th gear unless above 80 (which I really don't ever drive that fast).

 

[omnitonic]

I didn't realize Willys came with 3.45s and 32s. That's fairly under-geared. Looking at 1820rpms at 70mph in 6th, vs 1860 for a sport, or 2123 for a rubi. I drove for over a year with 3.45 gears and 33s and I couldn't stand it, basically left it in 4th gear unless above 80 (which I really don't ever drive that fast).

I was curious, so I dicked around with the new Jeep configure tool. Every configuration with the 6MT that isn't a Rubicon comes with all the same gearing problems my Willys has. They're all set up for Florida or Kansas, but not for the Virginia/West Virginia border.

Oh well, at least I'm in good company, I guess.

 

[SpeedKills]

I have both a 6 speed JK and a 2019 JL. The clutch is weird on the JL. I can't get a feel for it. We changed to a rock crawler exhaust so we can hear revs better to compensate.
The JL shifter is much better than the JK. I just installed a B&M shifter in the JK and the JL is still better.
It needs 3.73 or lower gears with 33" tires.
If I had to do it again I'd get the auto.

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