Lurching in drive train problem

I would start by investigating the brakes. My daughter's Maxima once warped the drums and behaved somewhat as you describe.

Center diff can be tested. If automatic tranny, put FWD fuse in appropriate spot in fuse box under the hood. Wait! yous said viscous coupler. Well, just drive in tight circles/figure eights in a dry pavement parking lot. Jerkiness while turning would be suspect for center diff. If the brakes are dragging - the affected wheel should be much warmer than the other wheels after driving for a little while.

Are the tires all the same age/brand/size? If not, that can destroy a center diff.

You should add drive shaft U-joint to the list of suspects also.

Carl