This may get merged into the FAQ...  or not.  I am now to this stuff and still reading and trying to learn the terms and options.  Confused but it will get better.  Back a long time ago I ran SCCA with a welded up rear end.  About that time I also had a SAAB 96 V4.  I used to get up on 2 wheels in corners, the engine would rev, the inside wheel (in the air) would spin up and when the car landed again it made great shock to the drive ong. line.  I broke pieces.  Result was when you went around a corner, once the Diff turned a certain amount it would lock up like a Detroit Locker.  Now I am a fat old man but at the time I was young, lean and oil patch strong.  When the diff on a front wheel drive locks up, you can not turn the steering wheel.  Been there, done that.  I will disagree (on a technical level) with what I have seen posted that when a car / truck is going straight ahead that torque is applied equally to both wheels.  we can have that discussion if someone wishes but what I am here for is for the short answer of how to lock up the rears on my 2001 Tracker 4dr, auto V6.  Once I get Warn hubs on the front I can unlock for pavement and lock up + ? for the sand... for not extreme sand, I could just lock one hub to aid steering.  First I have a 3rd member to change, a engine to swap then Warn hubs and a lift kit... oh and there is the issue with skinny tires.  Always something...  So is there a consensus out of the Locker FAQ?

Take your choice - for an auto locker you can get a Richmond Gear/PowerTrax LockRight, or if you want a selectable locker, there's the ARB air locker.

Thanks, I believe that I have found the right part number.  I should do this while changing my 3rd member.  Now to sell a stock trailer for the money for this and tires or this and lift kit.  It is darn hot already in Paradise on the Rio but (as you have seen) washed the tummy of Amy, washed wife's car, washed part of Backhoe (need to finish job) so I can open the HYD system and change filters, then washed my ride (85 Town Car)

A Happy Day in Mudville (reference to a poem but really known as Paradise on the Rio).  My Lock-right came today.  Within a couple of weeks I hope to have it installed and with some pictures to share.  I do not intend to do extreme stuff but just in case what I am doing on the beach and back in the dunes get more extreme than I intended, I will be glad I put it in.  I could be a very long way from help... or what seems like a very long way to a fat old man.