Another Gear question

Been looking to do a gear swap on my 2000XJ. Its my DD on a 3" OME Kit running 245/75R16's on a set of rubi moabs. Its a 4.0 AW4 231 D30LP and 8.25 29spline. I run the highway alot for work averaging almost 100 miles a day round trip. With the 3.55's in it now its ok on the flat but when I get into the hills around Rauch Creek it starts to fall on its head and I have to keep bumping in out of OD.

I've messed with the gear calculators on a few sites and they say that I need just under a 3.90 ratio. I am on the fence with going to 3.73's or 4.11's currently. I want to get a little bit of pep back but not make it into a gas hog any more than it is with the amount of driving I do.

I know that for the front any swap means a carrier change.

For the back its just a gear set swap but I have been toying with also doing a rear disc swap. I can get a complete used liberty axle to take the brakes and 3.73's out of it I go that way.

Any input on the gears is appreciated.

4.10's. The extra few RPM won't hurt your mileage.

http://jeephorizons.com/tech/rpmchart.html

go 4.10.

the calculators dont factor in that your new tires WEIGH considerably more on top of their larger rolling mass. youll be happier a little over instead of under geared.

also, check out car-parts.com and see if you can find a HP30 already geared to 4.10 in your area. not saying the LP30 is a turn, but sometimes you can find whole new axles for cheaper than gearing.

I thought about doing the HP swap to the front but with it being a DD that only gets wheeled very occasionally I didn't really see the point. If it was more of a wheeler I 100% agree that a HP would be in order.

As for the weight of the new tires/wheels thats a good point. The moabs are a bit on the heavy side for an aluminum rim and the BFG AT's are not exactly light either. They are part of the reason I was thinking of doing the rear disc swap.

EDIT: I didn't really look at it from a cost point like you mentioned. I have an old D30 ARB laying around that I was either going to sell to off set the cost or use it in this to get around the carrier swap.

VAhasnoWAVES said:

but sometimes you can find whole new axles for cheaper than gearing.

Click to expand...

x2 on this. i would try to find an axle already geared to 4.10 before you go out and by new gears and everything. would definitely save you time and money in the long run.