Maybe I am telling you something you already know, if so sorry and maybe this will help someone else, but a locker doesn't work the way it is written a lot of times. Many times I see it written that "it locks up when needed to transfer torque to the wheel with the most traction".
When in fact, it is actually locked most of the time and only unlocks when one wheel wants to travel faster than the ring gear.
I compare it to a ratchet, it will allow either tire to spin faster than the ring gear (but not both), but will never allow either tire to spin slower than the ring gear. Because of this, it has to have a mechanism to "reverse" the ratchet for engine braking (so both wheels can't freewheel) and also using reverse gear, which uses a cam ramp to disengage that side. This mechanism will switch directions of actuation when you let off the throttle and go into engine braking. So if you are going around a corner or in a curve, and you go from accelerating to decelerating or vice versa, the mechanism will disengage and re-engage in the other direction, which will cause you to switch from driving with the inside tire to braking with the outside tire. This can create the clunking etc you refer to in your driveway. If you think something is wrong you can jack the back up a do a test to verify if it is working properly. I will copy it from the install manual (avialable online from eaton)....
Step1
With the engine turned off, raise NoSPIN equipped driving axle(s) until
all wheels are out of contact with any surface. Place the transmission
in gear or park so that the driveshaft is locked and does not rotate.
NOTE: Test for forward disengagement:
Step 2
With two people, rotate both wheels rearward, as far as possible to
lock both wheels.
Step 3
With the left wheel securely held in the rearward direction, rotate the
right wheel slowly forward. A faint indexing or clicking sound should be
heard as the NoSPIN disengages on the right side.
Step 4
With the right wheel slowly rotating forward, the left wheel should be
rotated slightly forward. This will lock both wheels.
Step 5
Again, rotate both wheels rearward, as far as possible to lock both
wheels.
Step 6
With the right wheel securely held in the rearward direction, rotate the
left wheel slowly forward. A faint indexing or clicking sound should be
heard as the NoSPIN is disengaged on the left side.
Step 7
With the left wheel slowly rotating forward, the right wheel should be
rotated slightly forward. This will lock both wheels.
Repeat steps 2-7 except, test for reverse disengagement. If the above
steps are completed successfully and rotating wheels disengage
easily by hand, rotate freely and evenly, lock both wheels when
required, and produce a faint indexing or clicking sound, then the
NoSPIN is properly installed and is functioning correctly.
IF EITHER WHEEL DOES NOT ROTATE FREELY IN EITHER
DIRECTION or does not lock both wheels as required, recheck the
installation of the NoSPIN in the axle. Also check hand and foot brakes
for possible drag caused by improper adjustment. Be sure that all
thrust washers have been removed from the standard differential
support case.
To check normal NoSPIN operation, drive the vehicle on a flat surface
with good traction, in a right or left circle in forward and reverse to be
sure that the outside wheel is free to overrun (i.e. that the outside tire
does not scuff). A clicking or indexing sound may be heard. The sound
of gear re-engagement may also be heard upon completion of the turn.
This is normal.
OPERATION TEST
Check to see that both wheels of each NoSPIN differential equipped
axle are driving. Make this test under load, so that engine torque is
applied through the NoSPIN differential with the wheels on the ground.
One way to achieve this load is to drive up against a solid obstruction
(on loose dirt or gravel, if possible) and attempt to spin both wheels
together. Perform this test in forward and reverse. (Exercise caution
when performing this test to avoid damage to vehicle or obstruction.)
Hope that helps...
