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-   -   33x12.5's with 4.10s or 4.56s for my needs? (http://www.jeepforum.com/forum/f9/33x12-5s-4-10s-4-56s-my-needs-1074846/)

bowserw 07-23-2010 08:43 AM

33x12.5's with 4.10s or 4.56s for my needs?
 
I have a 2005 TJ X w/ a 4.0L and a 6 speed manual tranny. I'm going to put a Rough Country 3.25 lift on it and go with 33x12.5 tires. I'm having a hard time deciding on either regearing to 4.10s or 4.56s. I'm leaning towards 4.10s but I'm not sure.

I do a lot of highway driving and wanted to keep the rpms close to where they are stock, that was my thinking on the 4.10's. looking at gear charts the 4.10s looked right to me, and they seemed like they would give a little bit more power than stock. I live in North NJ and there are some hills, I have to down shift now on big hills any way, so it wouldn't be a big deal to me if I had to do that after regearing. Also, its not a major concern for me, but I don't want to totally kill my mpg's. So what do you guys think?

I did search a lot to try to figure it out, but I couldn't find anything close enough to my situation to make a final decision. So sorry for adding one more gearing thread to the gazillion already up hear.

Thanks in advance.

Rafikie 07-23-2010 09:18 AM

Looks like you've already figured out what gearing you need for you application. nothing to think about

longbluerubi 07-23-2010 09:26 AM

I have an '05 LJ 4.0L with 6 speed manual with the 4.10 gearing, with a 2" BB and a 1" BL and I run 33" BFG A/Ts and it drives great, no issue with needing more oomph. The engine with the gearing handles my setup very well, and it seems it's pretty close to the setup you're looking to do.

rainglur 07-23-2010 09:32 AM

I have an 05 TJ with the manny tranny as well. When my 32's wear out I'm regearing and jumping up to 33's. I've decided on 4.10's. If you do a lot of highway driving I would say definitely go with the 4.10's. You'll easily be able to cruise in 6th (except on steep hills of course). You should end up around the 2400-2500 RPM range under 75 mph. I don't really like driving the jeep that fast anyway... I try to stay 65-70 personally. If you simply want to be able to run 33's without losing 6th on the highway, 4.10's seem to be the clear choice. :thumbsup:

TheBoogieman 07-23-2010 09:41 AM

Why does Jeep even make 3.07's.My 3.73's and 35's could handle 75mph with no problem.:(

Jeepzcb09 07-23-2010 09:50 AM

I like my 33's on 3.73's personally, i have enough power to stay in 5th on the highway and most hills, without having RPMS thru the roof and destroying my MPG

breckboarder55 07-23-2010 09:54 AM

Quote:

Originally Posted by TheBoogieman (Post 9837376)
Why does Jeep even make 3.07's.My 3.73's and 35's could handle 75mph with no problem.:(

To meet CAFE standards, and say that Wranglers can get XX mpg on the Highway.

robncar 07-23-2010 10:30 AM

Quote:

Originally Posted by breckboarder55 (Post 9837448)
To meet CAFE standards, and say that Wranglers can get XX mpg on the Highway.

Downhill with a tail wind... :teehee:

OP, I'd still go with 4.56 with the manual and 33's:

A regear is more than RPM matching back to stock. The addition of larger tires increases upsprung weight and rolling resistance. The installation of a lift to accomodate those tires places the vehicle higher in the windstream increasing drag. Usually, we add armor and heavy accessories, such as winches, that increase overall vehicle weight. These factors can be mitigated by lower (higher numerically) gear ratios. Placing the engine in an efficient RPM band will allow the available power to be used. Lugging a vehicle can cost MPG too.

Weeeee 07-23-2010 10:57 AM

I will eventually be looking to do the same, I am going to have 33's(31 current), 2000 TJ 4.0 with NV3550 and 3.73. Wasn't sure if 4.10 or 4.56 was best.

Jeepzcb09 07-23-2010 11:00 AM

if your only going to 33's and have 3.73's then your fine, i rarley have to down shift in fact i can accelerate pretty good up most hills, a friend has 3.73's on 35's while its tolerable,he rarly see's 5th

Unlimited04 07-23-2010 11:06 AM

Quote:

Originally Posted by TheBoogieman (Post 9837376)
Why does Jeep even make 3.07's.My 3.73's and 35's could handle 75mph with no problem.:(

yea if you never leave 3rd gear and dont mind loosing a whole gear. thats 1800rpm in OD...worthless without the Jet Stream pushing from behind, while going downhill.

for the OP's reference, Boogie's OD gearing with 3.73s/35s is equivalent to your 6-speed, with 3.07s and 35s...at 75mph in OD.

Who likes 3.07s with 35s with a manual?

You'll be fine with 4.10s or 4.56s. if you tow anything, drive in the mountains, expect to go to 35s or wheel rocks, go with 4.56s. if you can understand you'll be downshifting more to pass on the highway, then go 4.10s. mileage won't be much different as long as you don't use the skinny pedal, pass people frequently or weave in and out of traffic. the 6-speeds close and deep gear ratios give you room to work with.

TheBoogieman 07-23-2010 11:43 AM

Quote:

Originally Posted by Unlimited04 (Post 9837861)
yea if you never leave 3rd gear and dont mind loosing a whole gear. thats 1800rpm in OD...worthless without the Jet Stream pushing from behind, while going downhill.

for the OP's reference, Boogie's OD gearing with 3.73s/35s is equivalent to your 6-speed, with 3.07s and 35s...at 75mph in OD.

Who likes 3.07s with 35s with a manual?
.

You like to give your opinion on big tires and gears when you've never seen anything above a 31.I forgot you and your mom bought lemons and complain constantly instead of just dumping the LJ for an 02' auto TJ.It depends a lot on where you live.In Florida,3.07's and 35's might be fine.I never used OD with any vehicle I've ever had.My 03' could easily pull any hill here in va on the highway at 75mph(without OD).Od was for flat trips to Richmond and 20 mpg.My 5 speed 98' got 20 mpg and my bro's 05',6 speed on 35's gets 20 mpg highway.Numbers don't lie.Then again,I know people in high places.:oYes,the Pope does crap in the woods.:eek:
http://a.imageshack.us/img155/7600/proofofthepope.jpg

Jerry Bransford 07-23-2010 12:03 PM

First, most gearing charts are misleading for one simple reason... they only show the engine rpms with a 1.0:1 final drive ratio, not the overdrive ratio used in all of our transmissions with the exception of the older 3-speed automatic.

What does that mean? The rpms such charts usually show are what you would see while driving in 5th gear with a 6-speed or while in 4th gear if you had the 5-speed transmission. So most people don't realize that and they get mislead into buying gears that are too high, like buying 4.10 when 4.56 would have been better.

That said, your 6-speed transmission is geared lower than the 5-speed is which means the 6-speed gives slightly higher engine rpms than the 5-speed does. So you COULD get away with 4.10 gearing for 33" tires with your 6-speed even though we usually recommend 4.56 for 33" tires and the 5-speed manual transmission. If you are an ardent offroader, I'd go 4.56. If your 6-speed equipped Jeep really doesn't see a lot of trail time and it spends a lot of time on the highway, 4.10 would be ok. But, again, for a trail Jeep, 4.56 would be the way to go. :)

55willystruck 07-23-2010 12:14 PM

Wow, most of you must think I'm crazy then as I run 4.88's with my '05 6 speed. Oh and no, I wouldn't have it any other way-with 35's, I'd want 5.13 minimum and would likely do 5.38's... Then again, I wheel it, run it and tow with it so it must perform in all areas.

Best of Luck,

Mike

Rafikie 07-23-2010 12:23 PM

:drool: I want 5.38s


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