Maybe one side is dragging, spray both sides really good with WD40 or something. Check the hitch pin, make sure it not sheared off. Also make sure your Skidder below the auger are not dragging or your axle is not loose inside the bottom cover, that's what happen to mine, the axle bolt broke and the axle was flopping around inside and it was jerk all around.
If you need the owners manula or tech manual, Toro has them online if you have the model/serial number.
I found my 1974 5HP Toro Snow thrower manual online.
Go here.
https://homeownersolutions.toro.com/por ... PageID=459