4.10's and 245/75

[KJJosh]

So a little about my rig.

It an 07 with full OEM skids, Frankenlift 2, JBA 4.5 Arms, ARB with Warn M8000, and duratrac load C tires.

Before the swap to 4.10's the ****** would have to down shift to make it up any sort of hill (I live outside DC). When down shifting the RPM's would go up to 3500 and stay there until I was able to top the hill. I had to drive with O\D off to insure it would stay in gear and not down shift. Now that the 4.10's are installed I'm able to cruise at 70-75 without the down shift. From the looks of it I'm back to 20mpg!!!

For those of you that say they dont need 4.10's when running 265/75 your crazy!!! I'm running a 245/75 and needed it!!!! Would I do it again???? Heck yes!!!!!! I will report back after the gears are broke in.

 

[yellocoyote]

My 4.10's are most likely going in next month.

 

[ShafferNY]

After driving my girlfriend's '06 with the 42rle transmission and my '03 with the 45rfe, I can't imagine hers with larger tires. It just doesn't have the bottom end torque my '03 does. The transmission seems geared too high.

 

[J-Thompson]

After driving my girlfriend's '06 with the 42rle transmission and my '03 with the 45rfe, I can't imagine hers with larger tires. It just doesn't have the bottom end torque my '03 does. The transmission seems geared too high.

it is
the 45 has a 3 to 1 first and Reverse
the 42 is like 2.5 ,HUGE difference

 

[Jo6pak]

After driving my girlfriend's '06 with the 42rle transmission and my '03 with the 45rfe, I can't imagine hers with larger tires. It just doesn't have the bottom end torque my '03 does. The transmission seems geared too high.

How do I know what trans my jeep has? Is it per year, or something else?

 

[ShafferNY]

Yours has the 42rle. Sometime in '03 they phased out all the 45rfe's in favor for the 42rle's.

 

[Jo6pak]

Yours has the 42rle. Sometime in '03 they phased out all the 45rfe's in favor for the 42rle's.

Roger that, thanks

 

[waywardtravel]

I thought bigger numbers meant newer and better and superceeded and stuff.

 

[tjkj2002]

So a little about my rig.

It an 07 with full OEM skids, Frankenlift 2, JBA 4.5 Arms, ARB with Warn M8000, and duratrac load C tires.

Before the swap to 4.10's the ****** would have to down shift to make it up any sort of hill (I live outside DC). When down shifting the RPM's would go up to 3500 and stay there until I was able to top the hill. I had to drive with O\D off to insure it would stay in gear and not down shift. Now that the 4.10's are installed I'm able to cruise at 70-75 without the down shift. From the looks of it I'm back to 20mpg!!!

For those of you that say they dont need 4.10's when running 265/75 your crazy!!! I'm running a 245/75 and needed it!!!! Would I do it again???? Heck yes!!!!!! I will report back after the gears are broke in.

Yep Tom and myself keep saying it but no one would listen.Those gears do make a work of difference.

 

[tommudd]

Yep Tom and myself keep saying it but no one would listen.Those gears do make a work of difference.

:shrug: we try

 

[Atrus]

I'll have to remember this if/when I get 245/75's. If it helps driveability and MPG, then it makes sense to do it. No, the MPG gain may not totally justify the cost, but that plus driveability makes a strong case

 

[Clyde Frog]

How do I know what trans my jeep has? Is it per year, or something else?

Check your build sheet. My Jeep was built Dec 02 and has the 42 ******

 

[yellocoyote]

I still think that's odd.

 

[TruLiberty]

Good to know jeh, that your getting better gas mileage...