Car is shaking while speed over 80 km/h

2 days ago, the tension pulley of my accessory belt blew out on highway, my car was towed to a garage, I had pulley changed there yesterday. Today, I had the feeling from this morning that car was shaking while speed was over 80km/h, I never had this feeling before.
I think it might be an alignment problem, but how comes it suddenly appear to be this way instead little by little?
Or there might be another reason to cause this problem?

if the tow company hooked it up wrong they could have bent something or a tire could be out of balance.. Take it and get the tires balanced first if it still exist then I would go after tow company for an alignment.

Yeah I agree they could have done it when towing, tow trucks always mess something up on your car..........always get the flat bed never let them tow it on two wheels

might need a tire rotation...that can cause it...

Maybe somehow a wheel weight was knocked or fell off. But sounds like a tire is out of balance. Also, did you use Fix a Flat or some other tire repair in a can recently? These have moisture which collect in the tire and throw it off balance. Either way, have the tires checked at a shop for balance is the way to go.