In looking for my vibration problem I put mine on the lift and let the back wheel spin in 2nd gear and got the same result. Jumping around as you put it. I think thats probably normal on a lift tho because the tire is not hooked up and the wheel is constantly "catching up" and then slowing down as the engine cathes it again, if that makes any sense. Thats the best i can explain it, but i think thats the case.
I *think* i did this BEFORE i installed the new chain, but on the advice above i'll check out the link i put on. It's not the reaon for my problem tho because it had the vibes before the new chain.
