OK guys, I'm looking for a little input from those that have either of the above mods mentioned in the subject heading. I am thinking of either getting 5.14 gears for my X or going with an ARB Locker up front. First a little background on my Xterra. This used to be my daily driver, however a few months ago I bought a commuter car so now the X is just used for errands and recreational weekend driving. It is basically modded for offroad: 5" lift, ARB front bumper w/winch, skids, sliders, rear tire carrier, etc. Since I only drive it 1-2 days a week now I plan to just leave my 33" BFG MT's mounted year round as opposed to switching between street tires (thus allowing me to sell said street tires/rims). So my question is this, I would like to get better performance from the truck while running the 33's. From my searches going to 5.14 gears will get me back (or at least close) to stock gear ratio and performance. On the other hand, since this is also going to be an offroad rig I would like to get an ARB airlocker for the front. I have the LSD in the back and figured the open diff up front would be better to lock up since it is the weak link with regards to traction off road. I only have enough money to do one of these at a time so I'm torn as to which to do first. On one hand I can get the gears which will do little for me offroad, but will make my weekly driving around town a little better and easier on the engine. On the other hand I can lock up the front and have a lot more offroad traction, however I don't really wheel every weekend so I would not get as much use from the locker as I might from the gears. I'd love to hear other pros/cons on each option.

I'd lock the rear.

1) Lockers are Ah-SUUUUM. It's incredible how much capability a locker adds. Regearing the axles is definitely worth doing - but in terms of bang for your buck, you'll LOVE the locker.

2) A front locker makes it VERY hard to steer - so you don't generally use it except to get over a specific obstacle/rock/whatever. With the rear locker, you still don't want to leave it on except when you need it - but you can use it more liberally (like turning it on at the beginning of a tough trail or a long hill climb with turns etc). It is easier on you, the front ground tackle, and the steering system.

3) I don't know about your LSD - but mine was worthless. Yeah, one locked and one LSD sounds better than locked+open - but see point #2.

Gears will give you better throttle control for offroading. However, that won't matter a bit, if you can't get traction to the ground.

Your rear LSD is worthless, for offroading. LSD=good for we pavement LSD=bad for offroading.

Lock the rear, first. Then decide if you will ever need/want to lock the front, based on your driving skills/locations/enthusiasm. Locking the front, first, is a waste of $$, as it will not benefit you nearly as much as locking the rear, due to Kaiser's #2 response. You just won't have many situations where you'll be able to use it.

vote #3 to lock the rear. A front locker without a locked rear is a recipe for broken parts, not to mention the fact you can't turn when locked. You'll get a lot more reliable performance gain from a locked rear end. The gears are nice to have, but with a V6, probably not worth the expense. If you want deeper gearing off road, it'll cost about the same to get a set of Tcase crawler gears for truly awesome offroad ability.

I'd do lower t-case gears before sinking big bucks into diff gears.

Then I'd get a front locker just to piss everyone off.

Also depends if you have a stick or auto. Our converters are fairly loose (high stall) and 33" are not a problem in 4Lo.

On the other hand, if you do have a stick, then 33"s would put you into a more efficient RPM at highway speeds. In that case, yeah, to with t-case gears.

I agree with everyone on the locker issue. Even though the 00-01s have stronger LSDs than post-02s, they're still useless. Get a rear locker.

I have a similar situation. 8 year old Honda for daily driving.

The read locker is a great improvement if you want traction. Up here in Colorado, I also needed power, so I first installed the transfer gears.
Mod history: Lift, Gears, Rear Locker, front locker. I question why I did the front. Not enough oppertunities to use them yet. I have run nearly every trail I want with the various set-ups. The rear and gears really is all I've needed.

I would recommend the rear locker also. You have oxygen, so the truck actually still has some power. Drop down a gear or two for power.

I love my gears and rear locker.

Thanks for all of the opinions so far guys. To clarify I am only considering the diff gears for their on-road improvement of gear ratio and decreased stress on the engine, i.e. not having to downshift up hills so often. And my Xterra is an automatic. I live in Western PA which has a LOT of hills, it's not The Rockies by any stretch of the imagination but it's surprising how much time is spent traveling up an incline around here! T-case gears are overkill for my off-roading needs so they are not even in the distant plans. I understand what everyone is saying about the rear locker vs. the front. I remember reading a post recently arguing the topic and there was just as much controversy. My personal philosophy on it is that the front suspension is much more likely to leave a wheel hanging in the air rendering that axel completely useless. At least the rear LSD will give me some traction in the back. If I'm locked in the back and one of those rear tires gets air and the front isn't pulling at all then I'm trying to push the truck with just one wheel. If I'm locked in the front and at least one wheel is on the ground both front and back then I have two tires giving me traction. As for the steering issue, how often are any of us actually "steering" over an obstacle where we would use the locker? We pick a line and try to make it as linear as possible until we get over the obstacle. I'll turn the locker off as soon as I clear the obstacle enough to get both front wheels on the ground.

As you might be able to read between the lines I am leaning more towards the diff gears simply because I feel that I will get more use from them than I will the locker. If I'm lucky I get out to wheel once a month, a litte more frequently in the Summer, hardly at all in the winter. The problem is that I'm just not 100% sure that the gears will in fact improve the performance of the Xterra while running the 33's. However I know that the locker will give me added benifit when I do wheel. Thus the indecision.

Yes, they will make a big difference. Though I have a manual. Made 4high a lot more useable. But for all the cost and time consider saving for both, unless your married then I understand.