What would you do? regear or not?

[LagunaJim1]

No. I think their positions are that:

1) running it stock with 35's instead of the 33's it came with from the factory is absolutely fine, and that 5th & 6th - as overdrive gears* in the first place - were designed to have little power but good gas mileage.

2) regear to 4.56, and that while I would appreciate a little more power in 4th and 5th gears it is not worth either the money or the effort.

3) regear to 4.88 is not a mechanically sound choice as it takes ratios too far out of design ranges.


*then he explained to me what overdrive means -- it is an effective gear ratio less than 1:1. I still thought it was an extra set of gears grafted onto the side of the regular transmission like in 1960 lol.

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[LagunaJim1]

Stealing this from another thread, I think this apparently-knowledgeable fellow is making the same point as my favored shop.

 

[LLRubylady]

Stealing this from another thread, I think this apparently-knowledgeable fellow is making the same point as my favored shop.

Thanks for the info.
I know they say 35s are ok in stock gears but the power loss is evident, to me at least.
I may just have to be happy with my 33s. And truthfully it’s all I need.

 

[LagunaJim1]

For me, anyway, it's not about whether there is a little power loss with the 35's -- but rather is there a reasonable (effective/worthwhile) solution to it in proportion to the loss.

I love the way my 35's look on my new Rubi - no lift and the proportionality of the 35's to the wheel wells is now PERFECT.

For that I lose a little bit of power. Ok. This is my third Jeep, I am aware they are not performance vehicles.

I spend 90% of the year with no doors no roof, and there is no other vehicle that gives me the jollies this thing does! I've owned 4 Jaguars, a Maserati, a Beemer, a Benz, and even a Bentley -- and my current and only car is a JL!

 

[jimlove9771]

All you guys. Some of you have JK’s because of the 6 gears and a few of you have the newer 8 gear auto tranny I don’t know what the JK’s need but I can speak to the JL’s. The decision between 4.56 and 4.88 comes down to this. 4.56 is great for all around up to 35’s. It will get better mileage, improve performance considerably and relieve the stress on your transmissions. For most I would recommend 4.56. Either way you will fin$ that you use all 8 gears whereas if you don’t you will never get a out of 5thToIf you want a bit more performance then 4.88. Either way unless you just drive very conservatively you should regear. I know it’s somewhere between 1900 and 2000 (I paid 1980) but in the long run you will be happier.

 

[LagunaJim1]

All you guys. Some of you have JK’s because of the 6 gears and a few of you have the newer 8 gear auto tranny I don’t know what the JK’s need but I can speak to the JL’s. The decision between 4.56 and 4.88 comes down to this. 4.56 is great for all around up to 35’s. It will get better mileage, improve performance considerably and relieve the stress on your transmissions. For most I would recommend 4.56. Either way you will fin$ that you use all 8 gears whereas if you don’t you will never get a out of 5thToIf you want a bit more performance then 4.88. Either way unless you just drive very conservatively you should regear. I know it’s somewhere between 1900 and 2000 (I paid 1980) but in the long run you will be happier.

Thank you for your post. FYI, I have a 2019 6-speed manual in my JL Rubicon 2 door with 3.6L engine. It's not a JK.

So running 35's and with the stock being 4:10 you like the idea of going to 4.56 or even 4.88? What happens on the freeway at 80 with the 4.88 ?

 

[vavaroutsos]

Yeah I'm running 35 in Nitto trail grapplers myself.
I would be surprised if 48 lbs would make that much difference as well.
maybe instead of going down, you should go up to 37's and then regear haha

It's not just 48 lbs, it's 48 lbs of rotating mass. This has much more effect than 48 lbs of gear or people. It requires angular acceleration of the tire/wheel, not just directional acceleration.

 

[vavaroutsos]

forgive the total noob question, but how is driving on the highway at 70 rpm with 4.88 and 35s? I was told roughly 2800 rpm? I have no reference of what the stock rubicon rpm are at that speed.

See my gearing spreadsheet. You should be about 2450 RPM in 6th gear.

 

[LLRubylady]

Well had my tires changed back to stock yesterday. I got home and started to cry when I looked at my Jeep.
My husband, good soul that he is, told me to make the regear appointment and get it done. So that’s what I’m doing first thing tomorrow.
I know they are a month out in booking so hopefully by end of May I can get done and get broken in to hit the beach in late June.
Ugh! Newbie mistakes.
Now I’ll have to sell a brand new set of bfg ko2’s. But I suspect they’ll go fast.

 

[LagunaJim1]

It's ok. We all learn. I lucked into a great custom shop that I know has my best interests (not theirs) at heart. Their advice is always excellent. I'm on my third Jeep with their help.

I sold my stock Rubicon tires for $800 on Craigslist. K02 315's with no lift rock on my Rubi, and I'm getting the 4.56 regear in a couple of weeks. The gears themselves are on backorder from Dana Spicer. $1800 installed.

 

[LLRubylady]

It's ok. We all learn. I lucked into a great custom shop that I know has my best interests (not theirs) at heart. Their advice is always excellent. I'm on my third Jeep with their help.

I sold my stock Rubicon tires for $800 on Craigslist. K02 315's with no lift rock on my Rubi, and I'm getting the 4.56 regear in a couple of weeks. The gears themselves are on backorder from Dana Spicer. $1800 installed.

It's ok. We all learn. I lucked into a great custom shop that I know has my best interests (not theirs) at heart. Their advice is always excellent. I'm on my third Jeep with their help.

I sold my stock Rubicon tires for $800 on Craigslist. K02 315's with no lift rock on my Rubi, and I'm getting the 4.56 regear in a couple of weeks. The gears themselves are on backorder from Dana Spicer. $1800 installed.

2 shops told me ho 4.88. Another said 4,88 but 4.56 would be ok too.

 

[LagunaJim1]

2 shops told me ho 4.88. Another said 4,88 but 4.56 would be ok too.

How big are your tires? 35 (K02 315's are 34.5) gets 4.56 in a manual transmission. 37" tires get 4.88 - again in the MANUAL trans 2019 Rubicon.

If you read all the comments, this is the clear consensus here: 4.56 for 35's.

 

[LLRubylady]

How big are your tires? 35 (K02 315's are 34.5) gets 4.56 in a manual transmission. 37" tires get 4.88 - again in the MANUAL trans 2019 Rubicon.

If you read all the comments, this is the clear consensus here: 4.56 for 35's.

Mine are 35 Nitto ridge grapplers. I think 4.56 should be fine. But the shop said I would only notice marginal improvement with the manual. I have steel bumpers and rock slide power steps but that isn’t a lot of extra weight.

 

[LagunaJim1]

Are you often on the highway (60-80mph) ? If so, then 4.56 is for certain for you

 

[vavaroutsos]

Mine are 35 Nitto ridge grapplers. I think 4.56 should be fine. But the shop said I would only notice marginal improvement with the manual. I have steel bumpers and rock slide power steps but that isn’t a lot of extra weight.

Don't forget that it is not a simple matter of making the final drive ratio (including tire size) the same as stock. The larger tires are heavier and have much more rotational mass due to the larger size and weight. If you want the Jeep to accelerate like stock, the final drive ratio will have to change. The downside is you will be at higher RPM on the freeway, but not that much higher. IMHO, 4.56 with the 35" Nitto and manual transmission is a waste of money. If you're going to pay for a re-gear, I would go 4.88.

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