What gears to choose?

[joe b]

I have a 93 yj sahara with the 4.0 and 5 speed.
Currently has 3.07 gears.
The stock tire size was 205/75r15.
I have installed a 2 1/2 inch lift and 31x10.50x15.
I need to change the gears and dodge some math and found out 3.55 gears should put the jeep back to stock configuration.
But I have also heard of alot of people runding 4.10 gears.
I'm primarily going to be using the jeep to commute to work and plan on taking it on road trips.
Planning on running trails but nothing crazy.
Planning to drive from Missouri to Colorado and run some trails.
Any thoughts on 3.55 vs 4.10 gears.
Any help is appreciated please.

 

[DOWNS]

You COULD go 3.73 gears. 3.73 was a factory installed option on some packages and gear sets are available. Would be a good middle ground. 4.10s would be streetable daily on 31s in my opinion, assuming you don't drive 80-85+ everywhere you go.

 

[machoheadgames]

I did 4.10s with the 4.0 5-speed on 31s and it was pretty good but I often wished for 4.56 actually. A TJ rubicon comes with 4.10 and 30.5s so it’s not that crazy.

Currently in the process of regearing to 4.11 on a different axle and I’m going to run 235/75R15.

Definitely don’t go with 3.55, going “back to stock” is really not the right way to choose gears as 3.07 was a poor performing combination from the factory. I firmly believe nothing should be based on 3.07 ever.

If it were me and I were keeping 31’s, I’d be doing 4.56 for sure. 4.11 if rpm is going to bother you. It’s about 2550 vs 2850 at 70 (4.10 vs 4.56 respectively).

If it helps, tons of 5 speed guys on the TJ forum do 4.88 for 33’s and 5.13 for 35’s with the 4.0. That correlates to 31’s on 4.56, it’s pretty close to the same result. Everybody that does one of those combos seems to love the results.

 

[T-Rex Jeepster]

Running 3.07's on 31X10.5 15's with a 4.0...Does good on the highway but really disappointing in the hills. Having a house built now so I'm kinda' caught up with stuff, But really thinking about going to a 5.3/327 Chevy small block when I get settled in to the new place....

 

[joe b]

I did 4.10s with the 4.0 5-speed on 31s and it was pretty good but I often wished for 4.56 actually. A TJ rubicon comes with 4.10 and 30.5s so it’s not that crazy.

Currently in the process of regearing to 4.11 on a different axle and I’m going to run 235/75R15.

Definitely don’t go with 3.55, going “back to stock” is really not the right way to choose gears as 3.07 was a poor performing combination from the factory. I firmly believe nothing should be based on 3.07 ever.

If it were me and I were keeping 31’s, I’d be doing 4.56 for sure. 4.11 if rpm is going to bother you. It’s about 2550 vs 2850 at 70 (4.10 vs 4.56 respectively).

If it helps, tons of 5 speed guys on the TJ forum do 4.88 for 33’s and 5.13 for 35’s with the 4.0. That correlates to 31’s on 4.56, it’s pretty close to the same result. Everybody that does one of those combos seems to love the results.

Well I was given a free set of front and rear axles with 3.55 gears.
Can't beet the price.
Going to run the 3.55 for now and see how they do on trip

 

[machoheadgames]

Well I was given a free set of front and rear axles with 3.55 gears.
Can't beet the price.
Going to run the 3.55 for now and see how they do on trip

Run the 3.55s for now and you can build the 3.07 axles to deeper gears in the meantime if you want.

3.55 & 31’s is what I had when I bought my jeep and I was not a fan. Though to you, it will feel like a significant improvement over 3.07. It’s still quite sluggish though and 5th is too tall for anything but flat ground. I have to agree though that for free it’s a lot better than 3.07.

 

[TRevs]

I have 3.55 stock gears and am on 30’s; it’s good enough not great.