You can use the regular gear oils with TF lockers. Only the clutch-based LSDs require the synthetic stuff. I'd run the bargain 80W90 gear oil for the break-in period, which should be changed after 500 miles. The rear is easy to break-in, as it's always turning when the vehicle is moving. I have yet to get the 500 miles of drive time on the front axle. I've heard that some guys don't really worry about the front break-in and just change out the oil when they have a "good enough" number of miles or run-time on the front axle. If you want to run a better brand of oil after break-in, go for it. You can even go with the synthetic stuff, if you like.

As for the installation of the TF locker, I think it's pretty simple. My rear locker came pre-installed in a carrier with a fresh set of carrier bearings. So I can't give you hands-on advice. The only issue you may have is getting the proper clearance of the locker when it opens up to ratchet. That's set by the stock carrier's thrust washers, if I understand correctly. Here are 2 links to the Lock Right locker product sheets. The TF lockers are basically clones of this design. The first is the installation instructions for a Toyota 7.5" third member, which is very similar to the Sporty's third member (KIA actually used Mazda's design for the drive train... that's why the Miata & RX-7 diffs are drop-in on the front - the rear is identical, except for the ring gear flange being extended out to hold the 7.5" ring gear). This will give you a good idea of what's involved. There are also some good install videos on YouTube, if you care to look them up...

Lock Right Installation PDF

Lock Right Owner's Manual

Hope this helps! <img src="/forums/images/graemlins/patriot.gif" alt="" />

1997 Sportage 4x4, auto-trans, Warn manual hubs, 4" UPYOURKIA front lift, TJ 106AA rear springs, 2-5/8" body lift, 31x10.50 treads, SmittyBilt SRC front and XRC rear bumper, swing-out tire mount, OBX LSD front diff, Track Finder rear locker, 5.38 R&Ps and... really crappy gas mileage! <img src="/forums/images/graemlins/shiner.gif" alt="" />