In regards to the welded diff....
You won't break anything right away, it is too easy for the car to over come traction on the ground and slip a wheel first. But as time goes on the stress of running no differential fatigues the metal to the point it becomes very brittle and just snaps out of the blue.
This same thing goes for running older 4WD Subaru's in 4WD on hard surfaces. It won't just go bang the first corner you turn, but it does fatigue the gear set and eventually something will snap. I ran in 4WD in my old Brumby with the "weak" 4 speed for over 2000km on the road. We then stuck that gearbox in my brothers wagon and it got similar treatment. Then that wagon turned into the race wagon (look on youtube under my name to see how hard that car was thrashed over the 3 weekends I raced it). Finally the welded diff broke a stub in that wagon while racing. The next day I was having fun in the sand with it and blew up second gear (locked the box solid, until I done 5 or 6 5000rpm clutch drops and then second gear was no more). 2 hours later and the other rear stub broke, no noises, just fell off haha!
So what I am saying is you won't know how much it is weaking anything until the point comes where it is so fatigued it just breaks instead of slipping. They do last a very long time and a lot of punishment though! (4WD gears and welded rear diffs).
A diff that can be locked, using air or electro magnets, so that both wheels continue to recieve equal motive power. Technically possible however more difficult than for most 4x4 / AWD vehicles, due to the small dimensions of the diff. The 'Holy Grail' which some of us continue to hope for.
OEM Fitment to:
Auto-locker diff
A diff which locks via centrifical force as a result of the loss of traction to one wheel, which is triggered at a set torque level.
Hope you don't mind but I would like to correct you on these two.
A Clutch pack LSD uses multilayered clutches to create friction between the two output stubs. As the spider gears spin separately from the carrier (i.e you lift a wheel and the power spins just that wheel) the force of the spider gears pushing outwards (trying to come apart) pushes on the clutches and limits slippage between that spider gear and the carrier.
Auto Lockers work much like a ratchet. They really should be called auto unlockers as that is a better description of how they work. When driving in a straigh line (both left and right wheels rotating around at the same pace) the ratchet type side gears that replace your spider gears are locked. What locks these is the drive pin which usually holds two of the spider gears. This pin when driving forces the lockers driver gears into the driven gears. When you turn while the inside wheel is going slower the engine still drives that wheel, but the outside wheel of the turn wants to go faster. What happens here is the driven gear rotates just a little more then the drive pin (which is held to the carrier) causing the driver gear not to be driven by the pin but by the wheel. This allows just enough slack in the ratchet to unlock that driver gear from the driven gear and disengage that wheel from the diff momentarily. This is why when you drive around a corner in a car with an auto locker it goes "click click click" as that wheel spinning faster unlocks itself from the diff.
Hard to explain without pictures and animated diagrams but I gave it a shot!
