Gearing for 33s

[YonderNorthwest]

31s finally gave up on me. Sidewall just cracked while driving down the road. Pulled the trigger on a set of 33x10.5x15s.

I'm still on my 3.73 factory gearing behind an AX15 5spd. Dana 30 front, 44 rear. General consensus seems to be that I want 4.56 or 4.88 gearing for that combo. I tow a ~1,500 lb trailer often, so I'm opting to go the deeper route.

Can someone point me in the direction of which kits I should be considering? I believe I need thick cut gears for at least the rear, and from lurking in another thread recently, I've learned that Revolution seems to be the only manufacturer I should be considering (Yukon no bueno).

 

[thedustyboot]

I have the 4cyl SE Dana 35/30 with 33's. I went with Yukon 4.88 and I'm pretty happy with it. I think at the time of purchase I wasn't able to find 5.13's or they were just out of stock (very few brands have 5.15 for Dana 35/30).

Do you do much highway driving? Where I live the fastest highway speeds are 50-55mph. I've had these Yukon gears in my jeep for three years now with close to 15,000km on them and they've been flawless.

TL;DR just go with the 4.88

 

[Hamfists]

I’m running 4.56 gears with the ax-15 , and 33s if I were to do it again I would have used 4.88 gears , it’s fine until I need 5th gear

 

[Wildman]

Check out @Woodrow build since he's got close to the same engine & you guys are neighbors....

https://wranglertjforum.com/threads/woodrows-97-green-tj-moderate-build.51602/

And YES I'd recommend 4.88 gears if you plan on sticking with 33" tires. If there's a chance you'll go to 35's then 5.13's

 

[AndyG]

If there is ever a choice between 2 gear ratios that are close, choose the higher number.

In a Jeep, just a tad more can really help more often than not.

 

[JMT]

488 for 33’s and the AX-15 all the way!!!

 

[AndyG]

5.13 for 35’s and the AX-15 all the way!!!

Good point- so often folks would save a ton if they would just do what is inevitable-

As author Stephen Covey said, begin with the end in mind.

 

[JMT]

Good point- so often folks would save a ton if they would just do what is inevitable-

As author Stephen Covey said, begin with the end in mind.

Then I went back and re-read he wanted 33’s, but I think you’re right. Just go to 35’s and be done with it.

 

[Wildman]

Then I went back and re-read he wanted 33’s, but I think you’re right. Just go to 35’s and be done with it.

That depends on what he's going to do with it...

 

[AndyG]

That depends on what he's going to do with it...

It really does get down to staying the course. We see it all here-

Going big, sizing down, going back stock …. The cost of gearing is such a big financial commitment. You really do need to decide what you’re going to do with the rig long term-

You see a lot of hesitation when people start to re-gear and that is one reason.

The 42RLE is the tricky one in my opinion- in some scenarios I’d be happier to gear shorter and kill the overdrive.

 

[Wildman]

It really does get down to staying the course. We see it all here-

Going big, sizing down, going back stock …. The cost of gearing is such a big financial commitment. You really do need to decide what you’re going to do with the rig long term-

You see a lot of hesitation when people start to re-gear and that is one reason.

I'd swore when I was building my Jeep the first time I'd never go larger than 35's... So instead of building 1tons I built the axles I had.... And here we are with me wishing I'd gone bigger...

So it's why I always ask are your "SURE" you're going to stay with XX size tires. What are you planning on using it for.

 

[AndyG]

I'd swore when I was building my Jeep the first time I'd never go larger than 35's... So instead of building 1tons I built the axles I had.... And here we are with me wishing I'd gone bigger...

So it's why I always ask are your "SURE" you're going to stay with XX size tires. What are you planning on using it for.

We all go from not knowing where to start, to not knowing when to quit.

 

[JMT]

That depends on what he's going to do with it...

I’ve never experienced the need to vary on gear ratio relative to flat roads vs hilly vs mountainous. I’ve lived in all three and never saw the need to be undergeared. The moment you need the gear and it’s not there you have to downshift and the rpm’s launch into 4k+ territory. So, go deep or go home!!!

 

[Wildman]

I’ve never experienced the need to vary on gear ratio relative to flat roads vs hilly vs mountainous. I’ve lived in all three and never saw the need to be undergeared. The moment you need the gear and it’s not there you have to downshift and the rpm’s launch into 4k+ territory. So, go deep or go home!!!

I can't say what one with 33's & 5.13 would be like... I thought I was doing good with my 4 angry squirrels and 4.88's with 33's so I'd think with the 4.0 they'd be great. But that's only if he's staying there. And depending on how much highway driving he does.

GrimmJeeper gearing calculator is still the best option for figuring out what you might want & then asking.

 

[Wildman]

4.88 on the left & 5.13 on the right

 

[YonderNorthwest]

I'd swore when I was building my Jeep the first time I'd never go larger than 35's... So instead of building 1tons I built the axles I had.... And here we are with me wishing I'd gone bigger...

So it's why I always ask are your "SURE" you're going to stay with XX size tires. What are you planning on using it for.

I had told myself I was going to stick with 31s when I bought the last set 4 years ago. I was typically the guy pulling others out when they got stuck; no need to go bigger. Then I started pulling the M416 (Dinoot) on all my offroad adventures. Now I'm regularly the weakest link when in either snow, sand, or steep grades in loose shale.

Part of the reason I sprang for 33s with this new set is because of my current gearing. 3.73s paired with 31s is fine. 3.73s with 31s while towing a trailer up the pass blows. Regarding to 4.11 from 3.73 while staying on 31s is a waste of money. Now regearing to 4.88s, body lifting, motor mount lifting, tummy tucking, SYEing and throwing in some aluminum under armor is money well spent, am I right?

 

[Wildman]

I had told myself I was going to stick with 31s when I bought the last set 4 years ago. I was typically the guy pulling others out when they got stuck; no need to go bigger. Then I started pulling the M416 (Dinoot) on all my offroad adventures. Now I'm regularly the weakest link when in either snow, sand, or steep grades in loose shale.

Part of the reason I sprang for 33s with this new set is because of my current gearing. 3.73s paired with 31s is fine. 3.73s with 31s while towing a trailer up the pass blows. Regarding to 4.11 from 3.73 while staying on 31s is a waste of money. Now regearing to 4.88s, body lifting, motor mount lifting, tummy tucking, SYEing and throwing in some aluminum under armor is money well spent, am I right?

Well look hard at if you want your RPM's @ 2800 or 2950 when doing 70 MPH... The nice thing about going to 5.13's would be when towing and it'll give you that little bit more when going over a pass. And NO running your 4.0 @ 2950 won't kill it.. You can always slow down to 65 MPH too.

Even with 31's you'd want to go to 4.56 gears.

 

[L J]

5.13

~150 rpm (4.88 vs 5.13) is going to be all but imperceptible

 

[MikekiM]

I did 4.56 with 33's, AX15, 30/44. I have no plans to go to 35's.

Daily driven. zero complaints. Well,, maybe 1% of my brain explores "what if I had done 4.88"?

 

[Harold&Cat]

A year ago we set our Jeep up with 4.88 gears and 33 inch tires . After running the 33's for a year I decided that I didn't like the handling . I went back to 32 inch tires and the lighter tires sure made it handle better . The 4.88 gears and 32 inch tires work well with the 42rle .
All of this was just to point out that not everyone likes the bigger tires . I suppose it just depends on how you use your Jeep . We do moderate trails and also use it to run around town .