Are 31's too small for 4.10's??

What tranny?

I think Bill should change his name to JeepGoogle.com. Is there a reference site/picture he either does not have or cannot find?!

Im running 4.56 gears with 31's and an automatic aw4 tranny. I like it. KH

The OP says AW4. I'd run 4.10's with my AW4 in a second if I could afford the swap right now! Some might suggest 34's might be a bit big for 4.10's but it depends mostly on what you're into. If he finds 4.10 to low for 31's, run a 32x9.5 for the winter but I'd suggest trying them this winter before he sells them.

-Brian

: > ---- : > I am currently debating wether or not to sell my 31" winter tires or not. : > Installin 4.10's in near future and would like to know if the engine is : > gonna turn up too much for highway use! : > 4.0L engine with Weber Carb, mated to AW4 trans. : > Currently running 3.55's and it gets along just about right. Will be : > running : > 34" Swampers for trail but i like my winter tires for snow driving!! : > Help me! : > Justin : >

: >

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: :

Hi Jeff,

The formula to compute rpm with tire diameter in inches and speed in km/h is:

rpm = ( ratio * kmh * 209 ) / diameter

Your pal's Aisin-Warner auto trans has a 0.75 overdrive.

At 110km/h, assuming his 31's are actually 30.5", he should be seeing around 2000 rpm with his 3.55 diff. A change to 4.10 would give 2300 rpm at 110 km/h - much better.

What does he have for a transfer case? NP231? Unless he has a 4:1 low range conversion, the AW4's 2.80 1st gear would really suck when climbing rocks with 4.10s and the 34 inch swampers. Better to regear with 4.56 or 4.88, sell the 31s, and buy a set of taller street tires with a narrow contact patch and a decent snow tread: 33x9.50R15 BFG AT/KO.

Steve

Jeff wrote:

4.10s are good for 31s or 32s. Some guys might even go to 33s with them, but for my money, the 33s are the bottem end of the size to use with 4.56s.

Geese you guys....

I am running 3.31's turning 33's......

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

CRWLR wrote:

Looking at that chart it's easy to see why 5th gear in my '99 Sport is useless with the 30" MTR's on it. The stock 3.07 ratio is just way to damned tall. Ironically, in the lower gears when drifting down the forest roads or in low range playing in the rocks it's about perfect. Hmm.. 4.10's would make it work a lot better though..

Hi Mike,

'Sour grapes!' said the fox. ;)

I know you get nice mpg in 4th and your gearing works fine on the logging roads, but do you never miss 5th on the 401 or easier 1st gear starts or the ability to crawl slower when you meet an obstacle?

Steve

Mike Roma> Geese you guys....

They had to, need I remind you of the stock power plant?

: > The OP says AW4. : > I'd run 4.10's with my AW4 in a second if I could afford the swap right now! : > Some might suggest 34's might be a bit big for 4.10's but it depends mostly : > on what you're into. If he finds 4.10 to low for 31's, run a 32x9.5 for the : > winter but I'd suggest trying them this winter before he sells them. : > -Brian

Actually I don't miss 5th. One less gear to mess with. ;-)

I very seldom even use 1st low but know what you mean when boulder climbing/riding or riding up the side of a tree to squeeze through somewhere. Still I got to inspect my clutch surface after one year of use and the painted label was still on the surfaces... Most of the rock slabs I hit are still momentum and speed dependent.

I haven't ever even considered regearing.

Mike

Steve wrote:

lol You would be suprised. I go about 85 then I go about 5 mph. Morning rush hour is 5-11 am and evening rush hour is 1-7 pm. I guess I average 45 mph lol. KH