31's on 4.56 gears?

jimmydaux

NAXJA Forum User

Location

Centerville, Utah

• Aug 7, 2008

• #1

How crazy would it be to run 31s on 4.56 gears?

Im in a dilema.... Im stock 3.55 with tired bfgoodrich all terrains and Im looking to go to a mud tire. I dont have the money to do both tires and a lift and from what I read, 31's on my 3.55's are a bit undergeared as it is. I would prefer get tires first and maybe gears in the coming months. If I were to get 31's now and throw in some 4.56's before the tires wear out and drive them for their duration and then upgrade to 33's or bigger, would that be completely unbearable to drive? Could I comfortable hit the freeway on 31's with that deep of gear?

Its got me stumped on where to put my money.

Any input would be greatly appreciated.


Jeremy

 

ILLXJ

NAXJA Member

NAXJA Member

Location

Louisville, IL

• Aug 7, 2008

• #2

I loved it. I don't remember what the rpm's were at any given speed but 80 wasn't a problem. I averaged 17mpg combined & 19 on the interstate going between 65 &70. Also is great for off road. JIM.

 

smcdonaldaz

NAXJA Forum User

Location

Litchfield Park, AZ

• Aug 7, 2008

• #3

x2 - I just did a trip from Phoenix(1300ft) up to 7000ft East of Flagstaff in northern AZ and she did fine. Handled a 6% grade at 55 in 3rd gear no problem. Wheeled it to on my brandspankinew 31" BFG all-terrains. Do it, you'll be fine!

 

cal

NAXJA Forum User

NAXJA Member

Location

Hammertown, USA

• Aug 7, 2008

• #4

Remi did a trip to the rubicon and back (~600 miles each way) with 4.88's and 31's. He wasn't doing 80, but he had no problem keeping up with the other jeeps.

 

jimmydaux

NAXJA Forum User

Location

Centerville, Utah

• Aug 7, 2008

• #5

Well thats good to hear!!! Ive been torn but I think im gonna just go for it. Probably 31 inch Mickey MTZs till I can fit some good 33s or 35s a few miles down the road

 

ILLXJ

NAXJA Member

NAXJA Member

Location

Louisville, IL

• Aug 7, 2008

• #6

jimmydaux said:

till I can fit some good 33s or 35s a few miles down the road

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Then you will be disappointed. :doh: JIM.

 

CanMan

NAXJA Forum User

Location

Lake Tapps, WA

• Aug 7, 2008

• #7

31's and 4.56's kick ass.

 

CABXJ

NAXJA Forum User

Location

Whistler BC

• Aug 7, 2008

• #8

X2 I have had mine on the road (DD) for a few months now, 4.56 and 31' I feel brings it back to almost stock performance, running maybe 200 rpm higher, remember the sweet spot on the 4.0 is around 2400 to 2900 rpm and some times higher rpm means better mileage.

 

mecompco

NAXJA Forum User

Location

Fairfield Maine

• Aug 7, 2008

• #9

Do it. I ran 235x75s and 4.56s for much of last summer before the 33s went on, including a couple longish hiway trips with no problems. You can comfortably maintain at least 65 in OD.

 

I

icewolf73

NAXJA Forum User

Location

Carrollton, TX

• Aug 7, 2008

• #10

ILLXJ said:

Then you will be disappointed. :doh: JIM.

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Why? 4.56s are great for up to 35s especially if you are still driving your rig on the street. Its pretty much back to stock at that tire size and gear ratio. Now if you are just a crawler then you would want to go deeper and there is no reason you couldn't run 4.88s or even 5.13s on 35s, but for street (with lots of highway time) and trail 4.56s are the best set up on 35s.

On 31s you will be running higher RPMs than say 4.10s, but if you are planning on 33s and possibly 35s I would definitely go with the 4.56s now.

 

IntrepidXJ

NAXJA Member #647

Location

Grand Junction, CO

• Aug 7, 2008

• #11

icewolf73 said:

Why?

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because he will be used to the 31's and 4.56's.....

 

R

rooneypower

NAXJA Forum User

Location

Woodinville, WA

• Aug 7, 2008

• #12

If you have enough in your budget, run 4.88's. I love mine. Ive got 34's too. That and 31's would be sick.

Keil

 

JAS

NAXJA Forum User

Location

Ann Arbor, MI

• Aug 7, 2008

• #13

Go 4.88 if you have an instrest in going bigger than 33 in the future 31s will be ok for a while.

If you will never go bigger than 33 then then go 4.56 or 4.88 will be fine.

 

mecompco

NAXJA Forum User

Location

Fairfield Maine

• Aug 7, 2008

• #14

FWIW, if I could do it over, I would go 4.88. Sure am glad I listened to the advice here not to go 4.11!

 

rocknxj

NAXJA Forum User

Location

Clinton, Utah (SLC area)

• Aug 7, 2008

• #15

JAS said:

Go 4.88 if you have an instrest in going bigger than 33 in the future 31s will be ok for a while.

If you will never go bigger than 33 then then go 4.56 or 4.88 will be fine.

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I found a site that shows a decent tire/gear ratio. Maybe this helps a bit:

http://www.4lo.com/calc/geartable.htm

 

Last edited: Aug 7, 2008

I

icewolf73

NAXJA Forum User

Location

Carrollton, TX

• Aug 7, 2008

• #16

Street ability with near stock gas mileage up to 35s: run 4.56s - still great on trails.
Less time on street and better grunt on the trails: run 4.88s

If you have an 8.25, 4.56 is as deep as you can go.

 

E

emr1101

NAXJA Forum User

Location

Raleigh, NC

• Aug 7, 2008

• #17

ILLXJ said:

I loved it. I don't remember what the rpm's were at any given speed but 80 wasn't a problem. I averaged 17mpg combined & 19 on the interstate going between 65 &70. Also is great for off road. JIM.

Click to expand...

lol 17mpgs and 80mph??? you mean with 33s, right?

 

igotanxj

NAXJA Forum User

Location

Citrus heights

• Aug 7, 2008

• #18

he said 19mpg hwy between 65 and 70mph

 

E

emr1101

NAXJA Forum User

Location

Raleigh, NC

• Aug 7, 2008

• #19

but its about a set lower if you have a manual, i.e. - 35s for 4.10s (thats near stock, actually its a little deeper than stock), or 4.56s. beyond that and you wont be able to use 1st... for an auto its more forgiving...

 

stewie

NAXJA Forum User

Location

the Union of Socialist States, Amerika

• Aug 7, 2008

• #20

I have 4.56 running 31s in my 95 4.0 AW4 and love it. the throttle responce is great, better passing ability than with stock gears. I feel comfortable with my choice in gears even when going up to 33s or even maybe 35s.