toro 21 in commerical mower

[t j lawn care]

I have a 2005 21 in commerical toro lawn mower with a 6 hp Kawasaki engine with BBC. I hit a stump while mowing this week, and know the mower seems to have a vibration when the blade is turning. Any body have ideas on what is wrong, did I bend the crankshaft on the mower?

Thanks Jerry

[t j lawn care]

I have changed the blade and it still has the vibration.
Jerry