drive belt pulley a little wobble whats wrong

 

drive belt pulley is wobbling

 

Loose bolts, bent pulley. Simple fix, depending.

 

+1 to this....Plus it could be missing/loose bolts, or the bolts are backing out due to lack of loc-tite, or the threads could be stripped/rounding out because of too much torque being placed on the pulley-(i.e. burnouts or a really built engine), or even too long of bolts that are not allowing the pulley to seat against the hub.

 

Put in on a jack. Take a good look at it. Spin the back wheel and see what you you hear and see it doing. That will likely tell you what it needs.