Have a peak at my web page at www.larsdennert.com/4runner/arb for a couple more notes on how not to goof it up. Also ARB's instructions don't actually explain how to setup the diff. They only explain how to keep your existing setup (ie backlash and preload) If things go haywire I can give you instructions on how to set it up from scratch. It's a bit different than the average diff since its a clamshell.

Lars,
Gold Coast Cruisers |My 4Runner