I want to lift my Tracker a bit and put 31's on it.. My buddy who in his youth went through many Sami's says that if i do this then a locker is a must! He says lifting it and putting 31's on it won't improve it at all on a trail without a locker. Any truth to this?
Robert

He says lifting it and putting 31's on it won't improve it at all on a trail without a locker. Any truth to this?

Well Robert a locker is a wonderful thing and may take you places you could never go before. But, so will having the increased ground and rocker clearance, improved approach and departure angles of a lift and the improved articulation of suspension mods. Bigger off-road tires will provide a larger footprint and traction especially when run at lower air pressures. I run an open differential at present in my Tracker and although I will add a locker someday I am pleased to say it amazes me at it's off-road ability without one.

Look at it this way, you come across a 10" diameter log on the trail. With a lift and bigger you have enough clearance to drive over it with or without a locker. Without the lift you might just play teeter-toter on it even with a locker. 

I am sure not everyone will agree with me but I would say to make getting it off the ground a priority. Along with bigger tires and then worry about the lockers, lower gears, headers, cams, etc, etc, etc. 

www.teamlifeforce.net/suzuki.html

Shedder is 100% correct - 1000 horse power and lockers front and rear aint going to do didly if your wheels are not on the ground.
Lift your Tracker first and go from there - a lift is the platform that any great rig starts from.
I fitted a 3" lift the other day ( Calmini ) and went out to a trail that is no walk in the park. I would not have even looked at it before the lift but I am astonished at the results - went all the way to the top with my 215/65X16's still fitted - WOW
A lot of people who had given me shit before hand shut up big time at the top
Over ten years of wheeling did help with line choices but hey the results were very impressive .
Lift it first and enjoy

Just the simple swap from normal street tires to a tire with more aggressive tread is a big step.
When you get stuck in mud in a stock sidekick thats up to the bottom of your rim (maybe 3-4 inches)....while watching your buddy in a samurai with 31s (no lockers) go through stuff thats up to his doors, you realize that it matters.

Also, don't forget that a decent lift will help keep all four tires on the ground by giving you more flex.  As long as you've got all four tires firmly placed on the ground, you don't need the locker.

That being said.... LOCK IT UP ANYWAY !  Welding the rear gears is basicly free if you know someone that welds!  I've streeted a lincoln locked sammy for over a year and was amazed at how managable it was compaired to my friends lockrighted sammy.