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3.07 to ? w/Larger Tires & Lift

R

RAVC1

NAXJA Forum User
Location
Michigan
The rear axle ratio of both of my XJ's is 3.07. This is why I get good fuel economy.

I will be installing 32" or 33" tires and a small lift this fall. I'll cut fender sheet metal as opposed to using much lift.

I want to retain the good fuel economy and do not need to be concerned with rock crawling or acceleration. The most severe offroad use I'll see is on trails.

Can anyone offer advise on which rear axle ratio I should change to? Alternatively, do I need to change from the 3.07 as a result of the larger tires and my intended use. With my intended use in mind I do not expect to need a 4.10. Is this a question of tire size alone? I would think tire size is only one factor and use is the other.

Pleae advise.

Thanks,

Rick
 
Currently I'm running 31 x 10.5's with 3.07.
I have no fifth gear - meaning I never use it.
Unless I'm rolling down a hill, I can't even think about getting it into 5th.
4.56 would probably be the best choice. (one that I'm planning to make as well)
 
There is a sticky that will answer all your questions...
why are you going to run 32-33"s if your not going to go offroad? If fuel economy is your concern and your not going to take the jeep offroad then don't put bigger tires on it....
just a thought.
 
I switched from 3.07's to 4.10's in my Jeep with 31x10.50x15. My mileage hasn't suffered.
 
I ran 33's with 307's for a year and it was no fun. My mpg went from 22-23 to 15-16. No 5th gear and every hill I had to shift down from 4th to 3rd and once and a while 2nd. I had 456 installed and I now get 20-21 with 5th gear back. 410's might be a better use for you since it is a dd only.
 
I'm hoping I can get some help out there.
I have a BDS 3" lift.
No complaints with it other than squeeking - afterall it has a lifetime warranty and came complete.
My XJ is my DD but I also use it for trails - nothing too crazy - I'm new at this
I would like to put 32's on, which shouldn't be an issue with fender trimming.
But I do have a question on the SYE.
I have a 96 which requires the SYE for lifts over 3".
With the BDS kit, I received a 1" transfer case drop kit.
I want to remove that to gain that extra clearance on the belly.
So my actual question is, If I put an SYE in, will I need to replace my driveshafts, or can I use the stock shafts?
 
You will have to replace the rear driveshaft. You could buy an aftermarket one like from Tom Wood's or get a second front driveshaft and use it as the new rear shaft with the SYE installed.
 
I went with 31s and changed to 3.55's & it runs about the same as stock, with a 5 speed. I went down to the yard and pulled the axles from a automatic jeep, & its a easy way to regear for a fraction of the price. Its something to think about if you are not going too deep in the gearing, I did it because im poor.
 
put the lowest gears your axles allow...

I ran 5.13's and 33's, got decent (20mpg) mileage...

it pulls hard now - like can redline the engine in 5th gear on the highway at about80...

I love it...
 
XJ_ranger said:
put the lowest gears your axles allow...

I ran 5.13's and 33's, got decent (20mpg) mileage...

it pulls hard now - like can redline the engine in 5th gear on the highway at about80...

I love it...
Click to expand...

good lord that's crazy.
I was looking at these axels for my AX-15 (5-speed) XJ that are a ford 8.8 and a HP D30 with both locked and geared at 4.88's and I was only gonna run 33's at most, I think I'll pass on the axels as they are way to geared for my use. I would be fine with 4.56's but 4.88's are insane, as are 5.13's!!!

I have the same set up as the OP (3.07's with 32's) right now and I get pretty decent MPG's, I would say 280 miles on a full tank on my '98. I wonder if it'll go down if I do 4.56's... which I will deff. need with the 32's.
 
Look around for 4 bangers they often have 3.73 and 4.10. Drop-in axles are often dirt cheap compared to regearing. Generally come with a 30 day warranty from a bone yard.
To regear will need a front carrier plus install kits beside gears and labor and dropins start looken real cheap.
 
Last edited:
selarep said:
good lord that's crazy.
I was looking at these axels for my AX-15 (5-speed) XJ that are a ford 8.8 and a HP D30 with both locked and geared at 4.88's and I was only gonna run 33's at most, I think I'll pass on the axels as they are way to geared for my use. I would be fine with 4.56's but 4.88's are insane, as are 5.13's!!!

I have the same set up as the OP (3.07's with 32's) right now and I get pretty decent MPG's, I would say 280 miles on a full tank on my '98. I wonder if it'll go down if I do 4.56's... which I will deff. need with the 32's.
Click to expand...

4.88's on 33's is what I'm running, Lost 4-5 MPG on the highway when I stepped up to 4.88. I had 4.10's before, honestly I liked them better for what I do. Occasional downshifting uphill but 19 MPG highwy Vs. 3k RPM at 75, never downshifting and sucking down gas.
 
goodburbon said:
4.88's on 33's is what I'm running, Lost 4-5 MPG on the highway when I stepped up to 4.88. I had 4.10's before, honestly I liked them better for what I do. Occasional downshifting uphill but 19 MPG highwy Vs. 3k RPM at 75, never downshifting and sucking down gas.
Click to expand...

wow yeah I'm deff. gona get 4.56's at most. even with a 5 speed, I'll still be getting good gas. I do mmostly freeway driving, maybe %10 off roading... so I need that 4.10 more but the 4.56 is just good power though.
 
I've got 4.10's with 31's on mine with a 5spd and to me it feels like I could have went with 3.73's.... of course I'm going to step up to 33's when these wear out, and then it should be perfect.
 
IslanderOffRoad said:
I've got 4.10's with 31's on mine with a 5spd and to me it feels like I could have went with 3.73's.... of course I'm going to step up to 33's when these wear out, and then it should be perfect.
Click to expand...

hows your MPG's?
 
selarep said:
hows your MPG's?
Click to expand...

Seems about the same but its tough to tell. I don't drive the Jeep daily, and I haven't corrected the speedo yet. Since its a toy mileage isn't a huge concern to me.
 
I am running 3.07's and yeah the gas mileage isnt the best, I have been doing it a year now. I still have alot of fun playing in the mud and crawling, just in low so I have the torque when I need to spin 'em. I am currently sin the process of a swap from the ba10/5 to an ax-15. oh forgot I am running 33's also.
 
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