How do you tell if your diff bushing is shot?

[dongoesby]

I try to narrow down my questions. What do you feel when your diff bushings are shot?

I have nismo 1.5way diff with stock rubber bushings on a s14. (the driver side axle suffered a slight accident impact and has a tard leak, but not much)

New clutch, flywheel and motor and tranny mounts and assume nothing wrong wirth my driveshaft (installed correctly), I suffer jerky 1st gear start for the past 1 month after SR swap.

Every gears are awesome, except first, which I have to play with the friction point and gas to minimize the jerkyness/clunks/shakes. Whenever from a dead stop, the car has to jerk/shake for a sec or two before moving smoothy. If the car did not stop fully, i can manage a smooth 1st gear start like how it should be doing every single time. Is this a symptom of shot diff/subframe bushings? or a bad 1st gear synchro? I don't feel a bump whenever I shift.