Help with my 2004 LJ gearing please

D

David Reid

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Mar 1, 2018
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Location
Augusta, GA, USA
Have a stock 2004 LJ, 4.0, auto, 3.73 with rear LSD that I've put 31" tires on. No interest in lifting.
Would like to do some mild to moderate off-roading, nothing too challenging.
Question is:
Will re-gearing improve the performance either on-road (90%) or off-road (10%) ?

If so, what thoughts are out there about what gearing to change to?

Also, while changing the gearing should I change the axles and/or consider a rear and/or front locker?

Thanks.
 
Yes, gearing will improve both on and off road performance. Yes, if you want lockers of some kind then now is the time to do it. No, you don't need axle upgrades running 31's and mild trails. If 31 is truly the largest tire you will run, 4.88 would be my recommendation. 4.56 will make a nice change as well but the 88 in 4th would put you in a better rpm range by a couple hundred.
 
'06 X here, 6 cyl running 4.56s on 33s with a 6 spd manual. I'm thinking about dropping to 4.11s as I'm on the road a lot as my DD. Kinda comparing apples and oranges since you have an auto trans...
 
mcj600 said:
'06 X here, 6 cyl running 4.56s on 33s with a 6 spd manual. I'm thinking about dropping to 4.11s as I'm on the road a lot as my DD. Kinda comparing apples and oranges since you have an auto trans...
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Yea, the 6spd and auto are much different. Going to 4.11 is a lot of coin for a couple hundred rpms. Are you running 75+ down the hwy?
 
Yeah, exact thing I was thinking. Not really worth the cash outlay for such a small change. 75-80 is about tops in 6th gear, rpms are up near 3K IIRC. Gets better mpg in the 60-65 range. That, and my X has the 30/35G2 combo. If I'm spending any cake on rears, I'll have to look for 44's ;)
 
David Reid said:
Have a stock 2004 LJ, 4.0, auto, 3.73 with rear LSD that I've put 31" tires on. No interest in lifting.

Question is:
Will re-gearing improve the performance either on-road (90%) or off-road (10%) ?

Thanks.
Click to expand...
Questions about your question - by performance, are you talking about acceleration, mileage, what, exactly? Does it feel sluggish at times, and if so, when?
 
glwood said:
Questions about your question - by performance, are you talking about acceleration, mileage, what, exactly? Does it feel sluggish at times, and if so, when?
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Actually on the road it's not bad. Perhaps a bit lacking in torque on the low end. Running 1900 rpms at 65 with OD. So on the road, yeah just a bit sluggish. Haven't had it long enough to get it off road yet so I can't comment on that. Thought someone might have personal experience to share.
 
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