Axle Ratio Change For Manual Transmission Gladiator.

[mrhemi]

Fist of all, I appreciate all of the knowledge shared on this forum.

I do not wish to start another gear ratio change thread as I know there are many already. I have read them and cannot find what I am searching for.

My Gladiator: 2022 Altitude (not a High Altitude). 3.6 Pentastar, 6spd. manual.
We all know the piss poor ratio selections in the supplied Aisin D478 trans. so no need for further debate there. I knew what I was getting into when I bought the Jeep. The clutch recall has recently been performed. Marginal improvement that I commented on in another thread. What I am proposing or inquiring about, for a manual trans Gladiator, has anyone changed from the supplied 3:73 ratio to a 4:10 ratio? My Jeep will not be driven off road much, if at all, so I am looking for an improvement in all around drive-ability. My tire size will remain at the stock (for a Willys) 255/75R17. Since the 3.6 has such a wimpy torque curve, it must be kept above 2000 rpm to have any throttle response. I would much prefer to have a trans with a single OD and more useful ratio selections, but the D478 is what it is. I ran the proposed ratio change through a gear ratio calculator and the results for the 4:10 ratio appear to offer better sizing for my purposes, though not huge. Keep in mind I am not looking for installing larger tires. I have attached a copy of the calculator sheet. The change appears to put the rpm s in the 2000+ range for improvement in torque curve position, without suffering hugely on economy (if at all). This also will give a bit of an improvement in trailer towing (not looking for a weight increase) as well as the ridiculous reverse ratio.

So, has any member done this and can comment on results? Any recommendations on a suitable shop in SW Ontario or the Detroit Michigan area?

My wife and I have 6 manual trans vehicles, 5 that we drive regularly. The Jeep Gladiator is by far the worse combination. The fleet and ranking follows if anyone is interested:
2023 Subaru WRX- pure pleasure to drive, right off the boat.
1969 Dodge Charger R/T- rebuilt a couple of times over the years, but a pure pleasure as well.
2013 Subaru BRZ (supercharged)- it required some external clutch mods and fluid change to get to where it is.
2014 Dodge Challenger SRT CORE- shifter changed to a Barton and a fluid change (which helped a bit). The Barton shifter throw reduction is too excessive as supplied. Barton will not make a longer shifter handle for me so that is a diy project on my plate.
2022 Jeep Gladiator- terrrible, hence the posting.

Thanks in advance.

Cheers,

mrhemi

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[Bbannongmu]

Probably not going to hear about many 4.10 gear changes. It’s just not enough to be meaningful and costs the same. My stock manual Rubi was not adequate - should have been 4.56 gears. Easier way might be to find Rubi take off axles and replace them. Good luck ! by the way the stick clutch also sux - I went @Centerforce Clutches and it’s much better !!!

 

[Thunderspud]

Can't comment on the actual swapping of the gears as my Rubicon with the 6spd came with 4.10s from the factory. I believe all of them did. I regularly tow a small (sub 1500lbs) offroad trailer and can't say that I have any real complaints with the MPG or gearing compared to when driving it without the trailer. I don't really notice it back there.

That said, the gear spacing is still gonna be such that 5 and 6 are essentially identical. There is a chart floating around somewhere here that illustrates this.

 

[Flyboy2109]

Man, do I agree with you, the ratios in this 6 are pretty bad. I never get to sixth...

My 1965 Barracuda with three on the tree was so much better.
My 1990 Dakota 5 speed is so much better
My 2004 Cad CTS V 6 speed Tremec is so much better.

Gotta wonder who chose this POS transmission? I wasn't going to have the auto...but I sure don't like this. Should be a lot tighter for the small displacement. Not good engineering, it is a poor match.

 

[Mightytalldude]

The manual was really "matched" to the Rubicon trim 4:10 axles on stock 32" tires. Any other trim, it's useable, but you better drive it like a sports car, higher revs, and not a truck. I have a Sport S, running 255/85R17 pizza cutter Mickey Thompson, and I'm planning to change to 4:88, plus add some lockers, to help the manual with the 35" tires, and its double overdrive 5th and 6th. That seems to be the best between usability and fuel efficiency.

 

[mendiola21]

My 6Speed Rubicon had the upgraded Falken Peak M/Ts from the factory and I did not like those very much either. I think 4.56 would have been the better selection stock with the 6Speed. I did recently go 5.13s with the 37s and they are perfect combination for me.

 

[Sandman 4x4]

Fist of all, I appreciate all of the knowledge shared on this forum.

I do not wish to start another gear ratio change thread as I know there are many already. I have read them and cannot find what I am searching for.

My Gladiator: 2022 Altitude (not a High Altitude). 3.6 Pentastar, 6spd. manual.
We all know the piss poor ratio selections in the supplied Aisin D478 trans. so no need for further debate there. I knew what I was getting into when I bought the Jeep. The clutch recall has recently been performed. Marginal improvement that I commented on in another thread. What I am proposing or inquiring about, for a manual trans Gladiator, has anyone changed from the supplied 3:73 ratio to a 4:10 ratio? My Jeep will not be driven off road much, if at all, so I am looking for an improvement in all around drive-ability. My tire size will remain at the stock (for a Willys) 255/75R17. Since the 3.6 has such a wimpy torque curve, it must be kept above 2000 rpm to have any throttle response. I would much prefer to have a trans with a single OD and more useful ratio selections, but the D478 is what it is. I ran the proposed ratio change through a gear ratio calculator and the results for the 4:10 ratio appear to offer better sizing for my purposes, though not huge. Keep in mind I am not looking for installing larger tires. I have attached a copy of the calculator sheet. The change appears to put the rpm s in the 2000+ range for improvement in torque curve position, without suffering hugely on economy (if at all). This also will give a bit of an improvement in trailer towing (not looking for a weight increase) as well as the ridiculous reverse ratio.

So, has any member done this and can comment on results? Any recommendations on a suitable shop in SW Ontario or the Detroit Michigan area?

My wife and I have 6 manual trans vehicles, 5 that we drive regularly. The Jeep Gladiator is by far the worse combination. The fleet and ranking follows if anyone is interested:
2023 Subaru WRX- pure pleasure to drive, right off the boat.
1969 Dodge Charger R/T- rebuilt a couple of times over the years, but a pure pleasure as well.
2013 Subaru BRZ (supercharged)- it required some external clutch mods and fluid change to get to where it is.
2014 Dodge Challenger SRT CORE- shifter changed to a Barton and a fluid change (which helped a bit). The Barton shifter throw reduction is too excessive as supplied. Barton will not make a longer shifter handle for me so that is a diy project on my plate.
2022 Jeep Gladiator- terrrible, hence the posting.

Thanks in advance.

Cheers,

mrhemi

Yea it’s posts like this that I had no problem ponying up for the automatic 8 speed, I find very well suited to driving comfort, performance and mileage, with the Adaptive Cruise Control System, I can set it as close to the vehicle in front, at my desired overall speed and as traffic builds and slows, so does my Gladiator at a set distance, in long stop and go traffic, as long as the stop is no more than 5 seconds the system automatically follows the car ahead at a pace of two car lengths. Very safely and not a foot on any peddle or hand on any shift! The best system I’ve ever had in long stop and go traffic, that actually maximizes the mileage in the worst conditions.

 

[mrhemi]

Thanks to those who replied. much as I expected, no one will do a swap to a 4.10 ratio from 3.73.

What I should have also asked was anyone's experience with a Gladiator that came with 4.10 axles (Rubicon?)

 

[Flyboy2109]

The manual was really "matched" to the Rubicon trim 4:10 axles on stock 32" tires. Any other trim, it's useable, but you better drive it like a sports car, higher revs, and not a truck. I have a Sport S, running 255/85R17 pizza cutter Mickey Thompson, and I'm planning to change to 4:88, plus add some lockers, to help the manual with the 35" tires, and its double overdrive 5th and 6th. That seems to be the best between usability and fuel efficiency.

I have a question: since I have the same Sport S outfit as you do. Does the 4:88 gear set go right into the Sport S pumpkin/housing or does one simply have to buy a whole rear end and housing?

Thanks, I am on the learning curve...

 

[Mightytalldude]

I have a question: since I have the same Sport S outfit as you do. Does the 4:88 gear set go right into the Sport S pumpkin/housing or does one simply have to buy a whole rear end and housing? Thanks, I am on the learning curve...

Same housing. Reason why I'm waiting, is to do lockers and gearing at same time, save labor costs.

 

[Mulinomafia]

I had 5.13 with 40’s and a MT. Switched to 5.38 asap.

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