37s No regear question

[Sikjeep2]

I ran 2 years with 4.10s and 37s. Regeared to 5.13 and regretted it, was way over geared was in 8th gear by 45mph. Now jumped to 40s and runs much better.

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[JTGuy]

My 37 BFG KO2s weigh 1 pound more each than my 315s did. They ride great and track straight . They are actually better than the 315s were in every way, IMO. With 4.88s I am doing 80 MPH at 2400RPM. in 8th. Travels easily at 80 if I want.

 

[OHJeeper]

Like a few others on this thread, I ran 37's for 2 years with 4.10's, but I drive a 6MT so my experience was different. I rarely saw 5th and never saw 6th gear. On the trails, I would stall frequently even with the Rubicon's crawl ratio - this will not apply to your 8 speed auto, though.

I finally went to 5.13's right after Christmas and I am SOOOO happy I did.

This doesn't mean you should, everyone's experience and preferences are different.

 

[Camaroboi13]

37s and 8 speed auto on 3.73s and love it. I see 8th gear every day. Why?

Because diesel.

 

[TheRealGinjaNinja]

37” KO2s in the context of this thread should be treated as slightly larger 35s. They run extremely small and light.

 

[kevman65]

I've got a '20 Rubi, will be putting on a 3" lift sometime this year (after it warms up) and will be going to 37" KO3's. I will run my 4.10's for a while and see how I like it.
I may go to 4.88's, but no more. The pinion gets weaker above 5.

 

[Deadpool392]

I've got a '20 Rubi, will be putting on a 3" lift sometime this year (after it warms up) and will be going to 37" KO3's. I will run my 4.10's for a while and see how I like it.
I may go to 4.88's, but no more. The pinion gets weaker above 5.

That was true of the rear pinion on my JKU, it broke a nice chunk off and had to be re-done. Ring was fine though.

Where are you going to get the KO3’s? I thought they were a Bronco or Ford only tire, but I could be wrong.

 

[kevman65]

That was true of the rear pinion on my JKU, it broke a nice chunk off and had to be re-done. Ring was fine though.

Where are you going to get the KO3’s? I thought they were a Bronco or Ford only tire, but I could be wrong.

Release date May 2024, so no rush getting the lift on. Would look kinda like skipping legs day forever with 35's under a 3" lift.

 

[JTGuy]

The BFG 37s are really a 35+ at only 36.5 true.

 

[Deadpool392]

Almost all manufacturers 37 inch offerings measure at 36.xx, that’s just the way it is. The real kicker is, once they are mounted and under the weight of the vehicle, some won’t measure 36 inches even…

 

[Sw00per]

I've got a '20 Rubi, will be putting on a 3" lift sometime this year (after it warms up) and will be going to 37" KO3's. I will run my 4.10's for a while and see how I like it.
I may go to 4.88's, but no more. The pinion gets weaker above 5.

Looking forward to hearing about this in the future.

 

[aevgladitorrubi]

One day I'm ready to pull the trigger on 35s and the next I'm back to 37s.

I see a lot of threads saying don't dare go 37s without a regear. Then also others saying no problem.

This is a daily driver, so the question is how hard on the transmission and engine are 37s really? Is it worth the concern? Thanks!

With an ecodiesel you can-- no issues

 

[Camaroboi13]

The BFG 37s are really a 35+ at only 36.5 true.

35.5 once they’re on the vehicle… just saying ?

 

[Vtur]

I'd be more concern with lugging the motor. Regear is always recommended. Those who regretted are usually went to low.

 

[mendiola21]

Like a few others on this thread, I ran 37's for 2 years with 4.10's, but I drive a 6MT so my experience was different. I rarely saw 5th and never saw 6th gear. On the trails, I would stall frequently even with the Rubicon's crawl ratio - this will not apply to your 8 speed auto, though.

I finally went to 5.13's right after Christmas and I am SOOOO happy I did.

This doesn't mean you should, everyone's experience and preferences are different.

What type of tires and wheels are you running for reference? I am going 5.13s with my Toyo MTs 37x13.5xR18 on Fuel Beasts

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