Re-gearing for 35s (need some build advice)

[97TJNM]

Also, regarding gear ratios: I have a 97, 4.0, manual (AX-15) that originally had 3.07 gears. I'm now on 35's, and I swapped in a set of axles that was already geared to 4.88. Now, is it a huge improvement over the 3.07? Yes. Am I generally happy with the 4.88? Yes. If I ever regear will I stay with 4.88? NO!

If I ever regear, I'll jump to 5.13 without hesitation. The 4.88 does fine around town, and I can't complain about their performance in the rocks, but I live in northern NM, in the mountains, and my jeep needs more gearing pulling hills on highways. With 4.88s I can cruise at 75 all day long on flat highway, but when I hit those steep mountain grades, I'm downshifting in a hurry and losing speed. If it's a particularly steep or long grade, I'm often in 3rd gear going 45 by the time I make it to the top.

Take it from a guy who has a nearly identical setup to you, and who lives in similar terrain. Go 5.13. You won't regret it.

 

[RockyMountain_TJ]

5 speed? AX-15? And they want to talk you down. Even if it was the NV3550 that is crazy. They should try living with it with your transmission for 6 weeks. They'd be regearing it themselves to 5.13.

I can barely survive on 4.56 with 35's and the 6-speed. I should have 5.13's all the way. There is no question here, and I have no idea why they would try to talk you down. It is your Jeep. Do what is right.

Think about this. Are those guys Jeep enthusiasts and purists? Do they sit around 365 days a year reading people's experiences and learning from the best? Do they really know all they claim to know just because they are named "The EDGE"? FUCK THAT.

I think the funny part is that their logo is literally a ring and pinion.

 

[ColoJeep]

Most of your driving is at 80-85? Really?

I've had my TJ at 90 m.p.h. once in 15 years , It felt and sounded like a B-17 in a 85 degree dive with the balls to the wall .

 

[jjvw]

My 4.88's work great for me on 35's but I get some added benefits from having the Rubicon TC

5.13 would still be nicer on pavement regardless of the transfer case.

 

[Jerry Bransford]

I've had my TJ at 90 m.p.h. once in 15 years , It felt and sounded like a B-17 in a 85 degree dive with the balls to the wall .

X2, I'm not buying his is driven that fast that often either.

 

[macleanflood]

97 4.0 AX-15 did 4.88s and wish I had done 5.13s.

Road to town is 50-60 mph and I'm either at 3k in 4th...which is pretty typical...or 2400 to 2500 in 5th which can get luggy coming out of turns and up hills.

-Mac

 

[Ocho]

X2, I'm not buying his is driven that fast that often either.

go fuck yourself

 

[Ocho]

I've had my TJ at 90 m.p.h. once in 15 years , It felt and sounded like a B-17 in a 85 degree dive with the balls to the wall .

shallower gears and sound deadening help with the sound immensely. Armorlite and a headliner in the Trektop NX are hearing saviours.

Can’t help you with the feel since that’s setup. mine feels solid up to 95

 

[ColoJeep]

shallower gears and sound deadening help with the sound immensely. Armorlite and a headliner in the Trektop NX are hearing saviours.

Can’t help you with the feel since that’s setup. mine feels solid up to 95

3.73 gears at the time , with the factory hardtop . It was relatively stable for a 93.4 " wheelbase . However, you are living on borrowed time in a Jeep at that speed. My 71 C-10 is far more comfortable at 115 and even that is kinda dumb . God let us invent CTS-V 's for high speed cruising.

 

[Ocho]

3.73 gears at the time , with the factory hardtop . It was relatively stable for a 93.4 " wheelbase . However, you are living on borrowed time in a Jeep at that speed. My 71 C-10 is far more comfortable at 115 and even that is kinda dumb . God let us invent CTS-V 's for high speed cruising.

yeah I'm not out there driving 95 in my rig, it was a curiosity play to check for vibes. tires have a max posted speed of 100 and I have zero intentions of testing that limit I got it up to 100 once when it was stock with a hardtop and that was an experience for sure.

I go out to the thermal track to get the speed demon out of me so I get to 150+ speeds in very stable cars but 80-85 is pretty standard without congestion on the freeways out here regardless of vehicle. passing box trucks that are going 75 isn't out of the norm. my jeep feels great at those speeds so that's how I drive. follow the rabbit and enjoy the ride.

 

[BlueC]

Just an observation, most of the guys suggesting 5.13s over 4.88 seem to be living at higher altitudes.

 

[jjvw]

Just an observation, most of the guys suggesting 5.13s over 4.88 seem to be living at higher altitudes.

Irrelevant. Mine has spent plenty of time at lower altitudes and never have I thought the gearing should be higher.

 

[BlueC]

God let us invent CTS-V 's for high speed cruising.

That's my thoughts. I had mine upto 80 mph once, but it's just not the vehicle for that. I'll run down the highway at 70, but my Jeep is just much better at 60 and lower. If I want to go faster, I drive something other than my Jeep.

 

[Ocho]

Just an observation, most of the guys suggesting 5.13s over 4.88 seem to be living at higher altitudes.

looks like it's more of a grade thing to me. the 405 is flat AF. if I had to go over the grapevine even once a week I'd be geared lower.

 

[jjvw]

I've had my TJ at 90 m.p.h. once in 15 years , It felt and sounded like a B-17 in a 85 degree dive with the balls to the wall .

In the world of relatable references, mine feels like a tank in the battlefields on the Somme!

 

[jjvw]

looks like it's more of a grade thing to me. the 405 is flat AF. if I had to go over the grapevine even once a week I'd be geared lower.

Denver is as flat as Kansas is.

 

[NashvilleTJ]

In the world of relatable references, mine feels like a tank in the battlefields on the Somme!

Probably your springs….

 

[Ocho]

Denver is as flat as Kansas is.

Denver sucks

 

[Ocho]

That's my thoughts. I had mine upto 80 mph once, but it's just not the vehicle for that. I'll run down the highway at 70, but my Jeep is just much better at 60 and lower. If I want to go faster, I drive something other than my Jeep.

I don't disagree with any of that. driving 60 on the freeways out here is more dangerous than driving 80 though.

every once in a while my girl will leave her s5 at my place when she's out of town.. it's such a treat to cruise in it feels indulgent.

I only have one vehicle though so I'm stuck with what I've got

 

[jjvw]

Denver sucks

Yes. But that is beside the point.