3.07 to 4.10 gears with 31x10.5 tires (My opinion)

cpleasant · 05-06-2007, 11:38 PM

Don't know if this is where it should go, or if anyone even wants to hear it, but here it is anyway.

If there is anyone planning on doing this (I did so because I knew the Rubi's came stock with a similar combo, so I know it would be ok. Plus, alot of people here gave it good reviews. Finally I knew it would do ok with 33's when I finally go up that high, that is if it ever happens between school and part time work

) Here is my opinion after a weekend on Baltimore's streets and Maryland's highways.

Basically, it will be like each gear moved down one. 5th is like 4th, 4th like 3rd, and so on. Starting in second (which I tried just to see what it would do) is exactly like starting in first with the 3.07's was. Just imagine shifting through 1st-4th gears on the 3.07's. That is what 2nd-5th is with the 4.10's is like.

It has great get up and go (my 02 x also had great pep with the stock tires when it was new, although I have heard people say otherwise about their stock rigs). No more stepping on the gas in first and waiting for it to get up enough a** to get going. You want it to move, it does so happily.

The top end does run a bit high RPM wise. At 65mph (I believe. From what I'm being told 4wd.com's, where I ordered my parts from, speedo gear chart is off. Won't be able to give exact numbers until I get a hold of a GPS unit) RPM was at about 2250 in 5th on the NV 3550. Don't remember where it was previously, but it was under 2000.

Around town (45 mph and under), gas milage should be the same, if you take into account the fact that to cruise at the RPM you are used to you will have to shift one gear higher. On the highway (50 and up), it feels like there should be a 6th gear (even the Jeep thinks so. The shift up arrow keeps coming on even when in 5th). So along with the higher RPM goes lower gas milage. Not really too bad (burned just under 1/4th tank on a 90 mile trip. Normally burned between 1/8th and 1/14th of a tank) but noticable in these days of $3 gas..

I no longer have to shift out of 5th at all. Acceleration is awesome on any hill. No more down shifting to 4th, or even 3rd sometimes, to pass, go up a hill, or to fight the wind.

In all, I like it alot. It has great power, although it does run a little higher RPM wise than I like on the highway. If you plan on going 31's and staying that way and you drive alot on the highway, 3.73's might be better. But if you like the low end power and you may consider going up one day, 4.10's are powerful with the 31's, would be great with 32's, and would do pretty good with 33's (at least it seems like it shouldn't be any worse than the 31's with the 3.07 gears was).

Whenever I find some mud (havent had time to in a LONG time due to school, work, and a horrible ex. School is done until Aug. The ex is done forever

) I'll let you know how it does there. I'll also post how the front and rear TrueTracs do as well.

If anyone found this useful, or if there is any questions, let me know. I'll answer any that come up. I know I had a few that I would have felt a little better about had there been someone with prior experience to walk me through it.

halltrail · 05-07-2007, 07:36 AM

Hey thanks....for the input. Ive got 3.07's and 31's now. I have an auto though. I going to 3.73's for now....unfortunately, I know I will be putting on 33's in 6 months.

defleppardsg · 05-07-2007, 07:59 AM

I found this very useful, thanks a lot for taking the time to post these results. I've also got 31's with 3.07s now and for a while, but I would like to regear one of these days too, in order to be able to really creep over rocks without nearly stalling. Problem is I do a lot of highway back and forth to school and its a compromise to regear and raise the rpms/worsen the mileage.

I didnt blindly buy this jeep but I certainly didnt know most of the info that I know now from this forum, and I really wish that I had gearing in mind when I bought it so I wouldnt have to wind up paying to regear to (3.73's) what many jeeps have stock.

Dogman · 05-07-2007, 09:02 AM

Quote:

Originally Posted by halltrail

Hey thanks....for the input. Ive got 3.07's and 31's now. I have an auto though. I going to 3.73's for now....unfortunately, I know I will be putting on 33's in 6 months.

Why would you regear to 3.73 if you know that you're going to 33s in 6 months?

cpleasant · 05-07-2007, 09:30 AM

From what I've been told 33s are a little more forgiving on auto trannys because of the torque converter. I've been told that 4.10's work great for 33s with an auto but 4.56 is optimal for a manual. Therefore 3.73s shouldn't be nearly as much of a dog for his as they would be for me.

Dogman · 05-07-2007, 11:16 AM

Quote:

Originally Posted by poopoo

From what I've been told 33s are a little more forgiving on auto trannys because of the torque converter. I've been told that 4.10's work great for 33s with an auto but 4.56 is optimal for a manual. Therefore 3.73s shouldn't be nearly as much of a dog for his as they would be for me.

Right, common recommendations are 4.10 for the 3 speed and 4.56 for the 4 speed auto/5 speed manual. He said he's going to 3.73 for now and then installing 33s in 6 months

pendleton · 05-07-2007, 11:22 AM

I will most likely be running 4.10's and 31's for a while when I do the 8.8 swap. This information is good to hear. Thanks a bunch. I'm just scared that after running the 31's for a while with 4.10's, I'll be wanting more power when I step up to 33's on the same gears.

cpleasant · 05-07-2007, 07:02 PM

After 60k miles of nearly 20mpg and 180 miles a weekend of higghway driving Im starting to wish I had a 6th gear. But I don't miss struggling to pass or even to keep speed.

halltrail · 05-07-2007, 09:55 PM

Dogman,

Good question...the only reason im going to 3.73 is that im buying a set of axles d30/35 with 3.73 gearing for about a 1/3 of the cost to regear. Id prefer the 4.10 and a dana 44...but havent had any luck finding any much less affordable right now.

badoosh27 · 05-07-2007, 10:08 PM

I have 3.07's and 32's right now and theyre not that bad...i dont know what the stock tires felt like with the 3.07, but it does feel a bit sluggish with the 32's. I want to go to 4.10's, but need some money. thanks for the input tho and keep us updated on the gas milage side of it.

BaddAndy · 05-07-2007, 10:27 PM

Dido with 32s and 3.07s with a 4.0l and NV 3550. I hear everyone say go 4.10, but it's almost good now, I'm torn between 4.10 and 3.73. 5th feels like 6th now, but I don't want it to feel like 4th. offroad I have no qualms with it the way it is. 4low with a 4.0 reduction ratio makes up for any gearing

Dogman · 05-07-2007, 10:36 PM

It's not that bad...until you feel correct gearing. I went from 3.07 to 3.73 with my 31s and I won't go to 32s because I'm not willing to loose my gearing right now. I'll go to 33s and 4.56 in a few years. I would not want to run anything less than 4.10 with 32s and a 5 speed.

I guess for me the gearing is more important than the looks or bigger tires. It all depends on your plans and how you use it.

Dogman · 05-07-2007, 10:37 PM

Quote:

Originally Posted by halltrail

Dogman,

Good question...the only reason im going to 3.73 is that im buying a set of axles d30/35 with 3.73 gearing for about a 1/3 of the cost to regear. Id prefer the 4.10 and a dana 44...but havent had any luck finding any much less affordable right now.

Ah...just curious, but that makes more sense.

cpleasant · 05-08-2007, 12:52 AM

If you have no real problems with what you have now and you NEVER plan on going bigger 3.73s would work for you. However, given my current situation I think the 4.10s would be awesome with some 32's. Makes me wish I had some. Anyone want to buy some bfg 31s with 10k miles on them

Quote:

Originally Posted by BaddAndy

Dido with 32s and 3.07s with a 4.0l and NV 3550. I hear everyone say go 4.10, but it's almost good now, I'm torn between 4.10 and 3.73. 5th feels like 6th now, but I don't want it to feel like 4th. offroad I have no qualms with it the way it is. 4low with a 4.0 reduction ratio makes up for any gearing

Tooch · 10-26-2009, 11:22 AM

what kind of things did you have to do when you swapped the axles? i just picked up a set of 4.10's for a hell of a deal. i plan on runing 33's with a 4" lift. The guy dropped off the axles with springs and shocks and everything on. So i just took it all off and left it in the back for storage lol but what did you replace and re do on the axles before install? thank you