I'm gonna end up build up a set of axles for my 99. I've got a 30/8.25 and I think I'm gonna end up building the same set. I don't do too much wheeling due to work, but when I do, it's mainly trail riding with mud. I'd like to run chromos, lockers and new gears, either 4.10s or 4.56s. That's my question. I do daily this Jeep. I've been told that 4.10s are better for highway. But will 4.56s be a better investment if I plan on going with a bigger tire later? Now, I'm talking a 35 nothing bigger than that. A 60/60 swap is planned for the 38.5s.

So to break that down:
4.10s or 4.56s for a DD with 33s.

 

Either will serve you well, but I think you'd be really happy with the 4.56s unless you run the highway a lot.

 

That's the thing. To wheel, I need to drive 45 minutes to an hour to my property, which is down the highway

 

That's nothing you'll be fine.

 

I really liked my 4.56/auto trans/33's. I think the stock drivetrain/axles are perfect for geared/locked 33's + street driving and I wish I could keep it at that tire size. loved it on the streets. the jeep feels a little doggish on the 35's now

get the 4.56's you wont regret it

 

Don't do mud but stock 3.55s are fine with 33s for crawlin and dd with 30/8.25s.

 

dd yeah crawling not so much , 456s prob your best bet

 

With my 3.55s, I can barely stay at highway speeds without sitting at 3k rpms. I'm also quite tired of the 9 city and 12 highway mpg's. I'm not expecting 20's but teens would be nice. Also, my rear spiders are gone and the front is also making a nice sound. It's about to upgrade

 

So I'm assuming that 4.56s are the way to go? How bad will they be on the highway though. Like on a 2-3hour drive?

 

it's really not that bad. the difference between 4.10 and 4.56 is like 200 rpm at speed. you'll be very glad you went deeper mine handled freeways like a champ. I view gears as a performance upgrade so I never calculated on 33's. but for my latest 150 mile trip, loaded down with heavy spare parts and camping gear and no doors on 35's I scored 17mpg. and that's going through the mountains. I'm sure you can do better than that

it was a total dog weighed down for that trip. one ratio deeper is definitely smarter in your case. regardless of slight difference in fuel economy

 

That's what I figured. I always said I would go 4.56s, but I was always told that it would be a tot Dog on the highway haha

 

not at all. I'm ashamed to say I've done better than 90mph on the freeway with that setup

 

I have the same stock set up, so 4.56's will be better than 4.10's on an hour drive going 75mph?

 

you will have to come to your own conclusions. I don't fully know what the engine like as far as RPM vs speed. play around with some gear ratio calculators

http://www.novak-adapt.com/knowledge/gearing.htm

http://www.grimmjeeper.com/gears.html


just to give you an idea. stock auto jeep does about 2000 RPM @ 65mph and 2315 RPM @ 75 MPH

4.56/auto/33's:
2250 RPM @ 65 RPM
2612 RPM @ 75 RPM


4.10's/auto/33's:
2035 RPM @ 65 MPH
2348 RPM @ 75 MPH

or so says the calculator. so whatever that translates to you in economy, take it as you will

 

Will 4.56's be a huge difference in performance from 4.10's on the trails? Say mud and some rocks