5.13 or 4.88 gears

Teeth may be smaller, but they see less stress from the lower ratio. Mechanical advantage is in favor of the gear teeth. Also, depending on how the teeth are sized, you may have more teeth engaged in a lower ratio than a taller one. It’s a non issue.
 
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They were completely wrong and behind on their knowledge of gears. They said the same thing about 4.88 when it first came out where they were obviously wrong there too. There are a lot of us running even a lower ratio in our axles, I'm running 5.38 and they have a sterling reputation for holding up to anything dished at them.

5.13 FTW ! Would have gone with the 5.38 but for keeping my Dana 30.
 
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I have a 03 sport 4.0L 5spd and I went with 4.88's and its been nice and its on 33s but once I put some 35s on I think it will still be a good choice. When I swap to jk axles or something thats when I would go with 5.13's. Hopefully offset some of that cost when I sell these axles since they are nice and loaded.
 
I have a 03 sport 4.0L 5spd and I went with 4.88's and its been nice and its on 33s but once I put some 35s on I think it will still be a good choice. When I swap to jk axles or something thats when I would go with 5.13's. Hopefully offset some of that cost when I sell these axles since they are nice and loaded.
Are you planning on bigger than 35's, for the JK axles?
 
What about fuel economy? Doesn’t seem like much difference in rpm on chart’s below, but would 4.88 be better?

Jeep and fuel economy don't belong in the same sentence. Unless of course the sentence is "Don't buy a Jeep if you want fuel economy!".
 
I have 4:88s in my crawler, 350 small block, turbo 350 with a 3.8 atlas, I like the extra wheel speed when I need to light it up a bit. They have been some tough SOBs.

There is like 1mph difference between 4.88/5.13 at 6000rpms in First gear with an ax15.
 
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back on topic sticking to stock engine and stock transmission, i was going to keep my current 4.56 ratio in anticipation of swapping to an auto, but i like overdrive too much and i'm going to stick with the manual..

since i habitually cruise at 80-85 and it's my dd, i'm thinking about 4.88 rather than the popular 5.13.. sure, i'll have a few more downshifts on hills etc but it'll be a bit less than what i'm currently doing and it won't act as angry when i'm at speed
 
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back on topic sticking to stock engine and stock transmission, i was going to keep my current 4.56 ratio in anticipation of swapping to an auto, but i like overdrive too much and i'm going to stick with the manual..

since i habitually cruise at 80-85 and it's my dd, i'm thinking about 4.88 rather than the popular 5.13.. sure, i'll have a few more downshifts on hills etc but it'll be a bit less than what i'm currently doing and it won't act as angry when i'm at speed

80mph my tach shows the first dot north of 3000 rpm. So, I am assuming 3200rpm. Thats with the 5.13 gears and the NV3550.
 
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back on topic sticking to stock engine and stock transmission, i was going to keep my current 4.56 ratio in anticipation of swapping to an auto, but i like overdrive too much and i'm going to stick with the manual..

since i habitually cruise at 80-85 and it's my dd, i'm thinking about 4.88 rather than the popular 5.13.. sure, i'll have a few more downshifts on hills etc but it'll be a bit less than what i'm currently doing and it won't act as angry when i'm at speed

Don’t pay money to go from 4.56 to 4.88……do 5.13 if you’re going to do it. Otherwise just stay on 4.56. A 7% gear reduction is not worth the cost of the regear.
 
Don’t pay money to go from 4.56 to 4.88……do 5.13 if you’re going to do it. Otherwise just stay on 4.56. A 7% gear reduction is not worth the cost of the regear.

yeah i wouldn’t if i was keeping my current Dana 30 and s35

swapping axles and the gears won’t carry over from one pair to the other so i gotta regear from the 3.73 in the swap axles
 
They were completely wrong and behind on their knowledge of gears. They said the same thing about 4.88 when it first came out where they were obviously wrong there too. There are a lot of us running even a lower ratio in our axles, I'm running 5.38 and they have a sterling reputation for holding up to anything dished at them.

They are not wrong that higher (numerically lower) gears are stronger. The more important question is are the lower gears strong enough for what we are asking of them? And the answer is for a 4.0 TJ with 35s and 5.38s they work just fine. Hell I would run 5.89 if I could find a set for a HP44.
 
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Teeth may be smaller, but they see less stress from the lower ratio. Mechanical advantage is in favor of the gear teeth. Also, depending on how the teeth are sized, you may have more teeth engaged in a lower ratio than a taller one. It’s a non issue.

On Dana axles they do get weaker as they lose the amount of pinion teeth contacting the ring gear as well as how small the pinion head itself is. If you want gears that get stronger the lower ratio you go that means something that uses hypoid gears like a 9 inch Ford.