Largest tires with 3.07 gears?

Cal

Cal

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Hoover, AL
so crawled under the Sahara and sadly saw that I’m running 3.07s....my plan was to get about 3-3.25” and run 33’s but now I’m not sure that’s very wise with my gearage. What’s everyone’s opinions on the largest tire to run with 3.07s? I imagine way down the road I’ll do a gear swap to 3.73s or 4.11s. Oh and this Jeep is going to be on the road 80% of the time and the other 20% will be hunting land and the occasional trail ride. Thanks as always.
 
im going to assume you have a 5 speed manual?

when i bought my jeep it had 3.07's with 31" tires. its was OK (ish) around town but trying to go more then 65-75 really sucked. i could barely use 5th gear at all. while this set up does "work" it was a real dog when it came to power. even on drive up an incline on a freeway 6% grade was rough constant down shifting back down to 3rd.
re-gearing is not cheap my advice is when you know what tires you want to run then you can re-gear for that size.
 
I have 32's on 3.07's and its fine around town and mild off road but as soon as you hit the highway it sucks. Any slight in cline or head wind and 5th gear is almost useless. I bought it that way and have no other experience, I plan on re-gearing as I also plan on running 33's.
 
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I just re-geared to 4.56 and 33's but i have not had enough time to give you true feedback on highway travel. i can tell you with 31's on holy hell did it have some get up and go. real fast off the line with out even trying. 33's have tamed it a bit but i still find plenty of power.
 
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Boinked said:
im going to assume you have a 5 speed manual?

when i bought my jeep it had 3.07's with 31" tires. its was OK (ish) around town but trying to go more then 65-75 really sucked. i could barely use 5th gear at all. while this set up does "work" it was a real dog when it came to power. even on drive up an incline on a freeway 6% grade was rough constant down shifting back down to 3rd.
re-gearing is not cheap my advice is when you know what tires you want to run then you can re-gear for that size.
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Automatic. Sorry I should’ve included that bit of info.
 
Boinked said:
I just re-geared to 4.56 and 33's but i have not had enough time to give you true feedback on highway travel. i can tell you with 31's on holy hell did it have some get up and go. real fast off the line with out even trying. 33's have tamed it a bit but i still find plenty of power.
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Yea mine came with 31” KOs.
 
I had 33" KM2s with my stock 35/30 with 3.07 gears (32RH). People said it was going to be absolutely horrible but seriously wasn't terrible. I personally think my Rubicon with ~31" with 4.11 gears is more of a dog at times (42RLE). I also don't live in a hilly, windy, etc area. Mostly flat, daily commute driving.
 
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I have 34" tires with a 5 speed and 3.07 gears. It's definitely no speed demon. The highway is the worst. I can only use 5th once I get to speed as long as its flat. Pulling long steep hills sucks and sometimes will drop into third. Passing sucks too. City driving isn't so bad but I tend to shift at around 4000 rpm. Off road isn't too bad and with 4 low I haven't needed any lower. Right now I'm saving my $$ for a rear axle assembly replacement and a front re gear. I'll probably go with 4.88 gears. Right now I get about 12-13 MPG which surprises me because it seems I'm always on the throttle. I'm curious as to what a re gear will do for my MPG.

My K10 with a 4 speed manual has 4.56 ratio and 33's and gets about 8 MPG pulling or empty but that's a 400 HP V-8.
 
Honestly it all depends on what your willing to live with. The thing your going to notice the most is power and crawl ratio. My jeep came with 3.07 and I ran 33 x 10.5 inch tires for years before upgrading to Rubicon axles with 4.10's. (I have a 5 speed manual) After the swap the jeep seemed like a rocket ship. The jump to 4.88 was not as noticeable. If you have some tools, a good area to work, and want to save some money it really is not to much work to swap the axles out. I'm sure you can find someone parting out a jeep with 4.10 and pick them up way cheaper then a re-gear. (just an idea)

Nimbley said:
I have 34" tires with a 5 speed and 3.07 gears. It's definitely no speed demon. The highway is the worst. I can only use 5th once I get to speed as long as its flat. Pulling long steep hills sucks and sometimes will drop into third. Passing sucks too. City driving isn't so bad but I tend to shift at around 4000 rpm. Off road isn't too bad and with 4 low I haven't needed any lower. Right now I'm saving my $$ for a rear axle assembly replacement and a front re gear. I'll probably go with 4.88 gears. Right now I get about 12-13 MPG which surprises me because it seems I'm always on the throttle. I'm curious as to what a re gear will do for my MPG.

My K10 with a 4 speed manual has 4.56 ratio and 33's and gets about 8 MPG pulling or empty but that's a 400 HP V-8.
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Good choice. I have 35 inch tires and 4.88's and couldn't be happier.

I got 13 mpg with my 4.10 and I get 13 mpg with my 4.88...... but crawling over rocks feels much better and its nice using 5th more often.
 
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Alex01 said:
Good choice. I have 35 inch tires and 4.88's and couldn't be happier.

I got 13 mpg with my 4.10 and I get 13 mpg with my 4.88...... but crawling over rocks feels much better and its nice using 5th more often.
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Thanks. Now i'm looking forward to it even more. I'm hoping to do it this fall when the temps are bit more pleasant.
 
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Alex01 said:
Honestly it all depends on what your willing to live with. The thing your going to notice the most is power and crawl ratio. My jeep came with 3.07 and I ran 33 x 10.5 inch tires for years before upgrading to Rubicon axles with 4.10's. (I have a 5 speed manual) After the swap the jeep seemed like a rocket ship. The jump to 4.88 was not as noticeable. If you have some tools, a good area to work, and want to save some money it really is not to much work to swap the axles out. I'm sure you can find someone parting out a jeep with 4.10 and pick them up way cheaper then a re-gear. (just an idea)



Good choice. I have 35 inch tires and 4.88's and couldn't be happier.

I got 13 mpg with my 4.10 and I get 13 mpg with my 4.88...... but crawling over rocks feels much better and its nice using 5th more often.
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Yea I live in Birmingham AL do it’s mildly hilly but nothing that bad. I would drive it on the highways to the hunting land that’s 2 hours away and that’s about it for long distance driving.
 
Damazzaro said:
I had 33" KM2s with my stock 35/30 with 3.07 gears (32RH). People said it was going to be absolutely horrible but seriously wasn't terrible. I personally think my Rubicon with ~31" with 4.11 gears is more of a dog at times (42RLE). I also don't live in a hilly, windy, etc area. Mostly flat, daily commute driving.
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“Soo you’re telling me there’s a chance?!”
 
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@Jerry Bransford has a fancy excel spreadsheet that will tell you what your RPM will be in with each transmission and gear selection. He pointed me in the right direction with my gear selection and has lots of first hand knowledge on the subject.

While driving with 3.07's and larger tires may be live able its really a night and day difference once you can get the tires and gears matched up just right.
 
Alex01 said:
@Jerry Bransford has a fancy excel spreadsheet that will tell you what your RPM will be in with each transmission and gear selection. He pointed me in the right direction with my gear selection and has lots of first hand knowledge on the subject.

While driving with 3.07's and larger tires may be live able its really a night and day difference once you can get the tires and gears matched up just right.
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Jerry seems to be the go to guy on these forums. Haha! I thought about going 2” lift and 32s for now but I could just do other upgrades and save up to do a proper lift, gears and tires. I just want to have a Jeep that runs smooth primarily on the highway but is capable for the 20% I have it off road (nothing extreme).
 
If you want it to drive close to stock, 30s. It will still go with any size you put on there though. As said it depends on what your willing to put up with.

For the 20% off road you're concerned with your Jeep will be more than capable on stock size or 30s.

33s you'll be underwhelmed and disappointed 90% of the time. The 10% of the time you'll be happy with it is when it is parked.
 
I need to do the same. 32 inch tires and 3.07 gears. It's ok on the highway but most of the time I have to down shift on a hill. Was thinking of going to a 3.73 gear

Sent from my SM-G950U using Tapatalk
 
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I personally wouldn't run anything larger than stock with 3.07 gearing. 3.07 is not even adequate for stock tires, 30" tires are a stretch.
 
3.07 and 20% of the time on hunting trails, 31's. For that type of usage 33's aren't necessary. If you must have the "look" and only 33's will get you there, your options are a re-gear or live with the lack of "power."
 
Cal said:
Automatic. Sorry I should’ve included that bit of info
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3spd auto, or 4spd OD auto.

With the 3 speed automatic there is no OD so highway driving will be fine. Maybe great. I ran 33s thru a 5spd with 3.07s. I never used 5th gear, OD.

With the 4 speed automatic, 4th, OD will be useless. PERIOD.

But the issue with the automatic will be lift from a stop. Even a minor grade will be hard on the torque converter. You can compensate off road by always using 4LO. In which case, with the 3.07s you will think you are in a Mustang. You'll be able to hit 60mph in 4LO. So if you like fast forestry roads as I did, you'll love 3.07s and 33s.

But no doubt, you will need a new torque converter sooner than with 3.73s.

Use this...

http://www.grimmjeeper.com/gears.html
 
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