3.07 gears with 31" tires

[cursed_hemi]

Hey guys, new member here with a 2003 TJ 4.0 5 speed.
Picked it up last spring and enjoyed it a lot over the summer with the doors and top off. Relatively new to Jeeps but not to cars. I've had plenty of modified mustangs and now have an 18' Charger Daytona.
I know this has been asked before but I'm really just looking for more opinions on it.
I'm looking at upgrading the wheels and tires to go a bit bigger, mostly for asthetics. The Jeep is mostly just driven around town, to the beach, etc. It's not a daily driver and almost never sees the highway and very minimal off roading.
I'm pretty satisfied with acceleration as of now, feels pretty strong for an old Jeep.
Just wanted some thoughts on running a 31x10.50r15 on the stock gearing (3.07). Currently has the stock 215/75/15s on it and it just looks weak.
Some guys say it sucks and some say it's not bad at all. I have no plans to re-gear anytime soon. Should I just stick with a 30x9.50? Just wanting to make it look a bit better.
Let me know what you think.
Thanks

 

[Cornbread]

I don't think you will have any problems with 31's, that's not a huge difference in tire size.

 

[Spic]

I was in the same position as yourself, had a standard wrangler 4.0 with 3.07 gears, but just generally disliked the standard hight and look of the tyres, so I moved up to a set of 31 10.50s, for me it didn't really feel bad at all to drive and really the only thing I noticed was the revs were lower in the gears, but that was fine with me.
I then fitted a 2"BB lift and trimmed my fenders 20mm that was great as it made the Jeep feel and look a bit bigger but at the same time it also made my 31's look small, so after lots of searching pics I decided the best compromise with my gearing (which like you I have no intention of changing) and my ride height that the best way to go would be to move up one more size to 32s, that would give me the look I wanted and hopefully not effect the the drive to badly, so after less than a 1000s miles I replaced my brand new 31s with 32 BFGs, for me it sorted the look right out, it's not crazy high but feels big and looks big enough for me, and if I'm honest it drives just fine with the 3.07 gears. First pic is on 31's second and third pics are on 32's with a 2" BB lift with the fender flares trimmed 20mm.

 

[cliffish]

where in NH was that pic shot? nice looking TJ

 

[Davidtj]

That is set up I have currently however I am planning on regearing in near future Since my Jeep had this set up when I purchased I can’t give you a before and after I can tell you would be better if crawl rate was slower and 5th gear is useless even on highway and I live in a flat state All that being said it might work out for you but I would plan on regearing

 

[Spic]

I keep hearing that 5 gear is useless with this combination, but I use my 5th all the time, altough I would be doing around 60mph or more and It is reasonably flat where I am (in the uk) but my gearing seems to be more than adequate for what i want, I cant say what it would be like off road though but for the small bit of greenlaning I do it's fine.

 

[Chris]

Friends don't let friends run 3.07 gears... on any tire size / transmission combo.



Can you live with it? Of course. However, go drive a re-geared TJ and then you'll see what you've been missing.

Truth be told, unless you've driven a re-geared TJ with the proper gear setup, you really won't know what you're missing, so it will seem completely normal.

 

[cliffish]

I have 3.73 with an auto on my 05, 31 x 10.5 and was dropping it in and out of overdrive highway driving yesterday. I usually don't do a ton of highways with the TJ so I am not changing it. But, I can see it as an issue for those that do.

 

[bucknut713]

You'll be fine with only 31s. I wouldn't waste my money on a regear unless going to 33s or 35s.

Sent from my..... Jeep

 

[ElectricWizard]

As someone with a 5spd, 31x10.5, and 3.07 I can confirm it's doable, but it sure does suck!

 

[Spic]

Truth be told, unless you've driven a re-geared TJ with the proper gear setup, you really won't know what you're missing, so it will seem completely normal.

Ye I can understand that, chances of that happening where I am is about nil though, I've only seen 5 TJ since owing mine (little over 9 months) and they were all standard, I also only drive about 200/300 miles a month, so it always feels good to drive when I'm out in it .

 

[Chris]

Ye I can understand that, chances of that happening where I am is about nil though, I've only seen 5 TJ since owing mine (little over 9 months) and they were all standard, I also only drive about 200/300 miles a month, so it always feels good to drive when I'm out in it .

Makes sense.

To be honest, I thought my 4.10 gears weren't that bad with 35s until I actually re-geared to 5.38. Then it was absolute night and day and I realized everything I had been missing.

But if you've never driven one with deeper gears, then you have nothing to compare it to, so then you can rest easy. Not a bad thing by any means!

 

[jazngab]

I’m running this combo now. It’s ok. I wouldn’t spend on a regear if I didn’t have to. It’s a lot of money. I did 75mph in 5th yesterday on the turnpike and I use 5th often enough although I do downshift a lot to accelerate. That all being said, I’m saving to regear to 4.10 only because I have to for my new to me Dana 44 axle to match the fronts. Once I wear the 31s out I’ll most likely go up to 32s. Never driven a properly geared Jeep so I can’t compare but I look forward to it.

 

[Hammer24]

I used had 3.07 gears with 31's, it drove fine, smooth, it got up to the speed limit which is all you need, but very slow. I since regeared to 4.10, only because my rear diff cooked it and it made more sense financially to do everything in one go (front and rear regear and lockers). The Jeep is more responsive, quicker, feels more powerful, but not really a huge difference for everyday driving so I wouldn't worry at all if I was you.

 

[TheGanzman]

I'm running that combo on my '04 4.0 5 speed; stone stock except for a .75" coil spring spacer lift. It ain't no rocket sled, but I don't think it sucks too bad neither; I changed out my speedo drive gear too, since I HATE any of my gauges being "off"...

Would I LIKE deeper gears? Sure - but it's pretty far down on my priority list. If for some reason I cook my differential, then I would certainly go up, but prolly no deeper than ~4.11's. It's not like this is some stoplight-to-stoplight street racer; remember too that the deeper the gears, the deeper your wallet needs to be when it comes time for (more frequent) refueling...

 

[Hammer24]

remember too that the deeper the gears, the deeper your wallet needs to be when it comes time for (more frequent) refueling...

That's also a good point, I noticed a HUGE difference when I regeared from 3.07 to 4.10. Like way bigger difference than I expected. When I had 3.07 gears I was going to remove my long range fuel tank because it kills a little bit of clearance, but I'm definitely keeping it now lol.

 

[jazngab]

That's also a good point, I noticed a HUGE difference when I regeared from 3.07 to 4.10. Like way bigger difference than I expected. When I had 3.07 gears I was going to remove my long range fuel tank because it kills a little bit of clearance, but I'm definitely keeping it now lol.

Being someone who went from 3.07 to 4.10 with 31s, did you notice enough difference that you recommend it/say it’s worth the price of regearing?

 

[Hammer24]

Being someone who went from 3.07 to 4.10 with 31s, did you notice enough difference that you recommend it/say it’s worth the price of regearing?

In terms of power and performance, yeah I'd say so. I wouldn't say it's anything crazy or drastic because I'm more used to it now but I remember the first time I drove it with 4.10's I was pretty surprised. So I'd say if you want a bit more power for wheeling then I think you'll notice it enough for it to be worth it.

 

[cursed_hemi]

where in NH was that pic shot? nice looking TJ

Thanks! Peirce Island boat launch in Portsmouth. That was a few months ago, it's cold and snowy here now.

 

[JPAZIDO]

I originally ran 31's with a 5 speed manual. I could hit 95 MPH on the freeway. 307's were my gears then also. YOur going to be fine. You will probably not be able to notice any difference. Look for someone who is upgrading gears from a Rubicon and take their 4:10's. Unless you have a Dana 35, Do you have a Dana 35? If you do don't answer. Just don't go anywhere you cannot walk back from easily.