6 speed gear decision input needed

[CorvZ061]

I’m about to get my wife’s Jeep regeared. Hers is also a 6 speed but a sport. Her Sport has my original Rubi axles under it with the stock 4.10’s. We recently did a small lift and 35x12.5-17 tires on my original Rubi wheels. Hers will never go bigger than 35’s and the 4.10’s just don’t cut it on the highway. We recently went to OKC from Amarillo and was in 5th pretty much the entire just to be able to go the speed limit of 75. 6th couldn’t maintain that speed even on flat road.

Those that have 35’s on a 6 speed, 4.88 or 5.13? I’m leaning towards 4.88 for the bigger pinion, but that’s not a huge deal on hers it’ll see some dirt roads and light trail use

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[roaniecowpony]

3.6?

That's a lot of gear at 75mph with 35s. You are kinda in a rpm range where you are starting to have plenty of power with 4.88s, but it's going to wind pretty tight. 5.13s may be a bit much for 35s.

 

[CorvZ061]

3.6?

That's a lot of gear at 75mph with 35s. You are kinda in a rpm range where you are starting to have plenty of power with 4.88s, but it's going to wind pretty tight. 5.13s may be a bit much for 35s.

Pretty sure 3.6 is the only engine option with a manual trans.

 

[roaniecowpony]

Pretty sure 3.6 is the only engine option with a manual trans.

Well, my thought is 4.56 would be about right. But, changing from 4.10 to 4.56 would be a subtle change. BTW, I'm on 37s with 4.88s with an auto.

 

[AVGeek99]

Strange that you have that level of issues running 35s with 4.10s. I put 40k miles with 35s on my otherwise stock 21 JLUR 6MT. I wouldn't say it was ideal in hill country, but it was perfectly acceptable 95% of the time. I rarely had no issues maintaining highway speeds in 6th gear on the interstate, except when I was in the mountains. The one thing that would give it trouble in flatter territory was a strong headwind, then it would struggle.

I lifted and regeard to 4.88s at 40k miles. Drove it for a few months before moving to 37s. I honestly can't say I liked 4.88s with 35s, too short, especially 1st. I was much happier when I finally put the 37s on. If I was never going to go bigger than 35s I wouldn't go higher than 4.56s. But that's a lot of money for only one gear step.

 

[Oletimer]

I had 4,88s with 35s on my last one. I think it was perfect.

 

[roaniecowpony]

Strange that you have that level of issues running 35s with 4.10s. I put 40k miles with 35s on my otherwise stock 21 JLUR 6MT. I wouldn't say it was ideal in hill country, but it was perfectly acceptable 95% of the time. I rarely had no issues maintaining highway speeds in 6th gear on the interstate, except when I was in the mountains. The one thing that would give it trouble in flatter territory was a strong headwind, then it would struggle.

I lifted and regeard to 4.88s at 40k miles. Drove it for a few months before moving to 37s. I honestly can't say I liked 4.88s with 35s, too short, especially 1st. I was much happier when I finally put the 37s on. If I was never going to go bigger than 35s I wouldn't go higher than 4.56s. But that's a lot of money for only one gear step.

I wonder if he got the torque management software for the clutch issue and it's restricting.

 

[Oletimer]

I wonder if he got the torque management software for the clutch issue and it's restricting.

mine i felt was the weakest thing I ever owned. I put 40 miles on it and decided I couldn't live with it. 4.10s with 35s
and I had already owned several jeeps.

 

[eastern]

Never met anyone regretting lower ratio, posts about wishing having lower ratio are numerous.

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