it is working just how it is supposed to... the tire that can spin the easiest will always be the tire that spins... unless you have a locker... many members here have lockers... the stock differential has an open carrier which allows both sides of the axle to spin at different speeds... but if you have a locker, it locks the two shafts together so they can't spin at different speeds.... if one side spins at Xrpm.. so does the other... there are many types of locking differentials... first is the lincoln locker, Bounty Hunter is the man to talk to on this, it is a the cheapest and easiest to understand design... the open differential's inner gears are welded together so that it doesn't allow any differentiating movement... Selectable lockers are usually functional as an open differential until you select for it to engage a locker.. then it will work just as the lincoln locker does.... A full time locker will always be locked, and will apply the same force to both sides at all times... but when there is enough of a difference in speed or torque needed... one side will let go with a "ratcheting" effect... this will happen mostly on dry pavement turns. Then there is a limited slip differential... this has a set of clutches in it, pressed together by springs.... the two axle sides will usually be locked together... but when you turn, or in any situation where one side needs to slip, if the difference in torque can overpower the springs holding the clutches together, it will allow for it to slip, acting somewhat like an open differential
any questions?