You have to free the shaft coupler from the vdrive plate. Either your 4 bolts were not loose enough or the coupler vdrive plate is frozen. I have found that with the nuts backed off 1/4 inch just start the motor and just pop it into forward and then shut it down. no damage to motor as only run for 3 secs and the torque should free the two coupler plates. You can't properly check alignment until these plates are apart then pulled back together and held tight by hand while you use the feeler gauge.