There are repair videos on the link below that will show you how to do it. Just copy and paste in your browser.
possible broken auger belt, or one that has slipped off the pulley
Got a toro 521 wont blow snow after 2 feet whats up
check for stretched or broken auger belt
you have to separate the front auger housing fron the back engine and drive housing. there should be several bolts on both sides you have to remove. once the two housings are separated you have to loosen off belt guard pins and pull the belt off. dissemble slowly so you can see how to reassemble
May possibly be a loose missing or worn belt.
Belt , Traction drive P/N 53790 and Bel t, Auger drive P/N 3526.
how to change belt on snow devil snow blower
Check your bearing on the shaft. Check pulleys for alignment also check bearing on idler clutch pulley.
Be sure that the belt hasn't stretched so it may be slipping. I don't think there is a actual adjustment but rather that it is either cracked or stretched too much to operate the auger properly.
To remove the metal cover over the drive belt, you need two 10mm ratchets because, while two of the bolts screw into the snowblower case, the other two bolts screw into nuts that you need to grab to keep them from turning. Both of the nuts are accessible through the mouth of the snowblower. FIRST, make the snowblower safer: shut off the ignition and remove the key. Some recommend disconnecting the sparkplug wire, but we did not--use your own judgement. Do not tip the unit or gas and oil may leak. Servicing will be easier if the unit is on a raised platform, though we did it on the garage floor in about ten minutes. SECOND, remove the four bolts from the cover on the same side of the unit as the Auger Clutch Cable (standing behind our unit, as if to push it, the cover is on the left; looking at the front end of our unit, the cover is on the right). To get the ratchet onto the nuts in the mouth of the snowblower, you may have to gently turn the blade a little to get it out of the way. THIRD, with the bolts out, lift the rear edge of the cover and slide it forward to disengage the front lip, which hooks onto the snowblower case. This exposes the belt and pulleys. You may find (as we did) that the belt has merely jumped off the pulleys, so it is worth checking even if you do not have a spare belt. FOURTH, before trying to get the belt back on the pulleys, squeeze and release the Auger Clutch Lever (ACL) and observe the movement of the Roller Tensioner pulley and the Auger Brake Arm. You will need to squeeze the ACL to get the belt around the Drive Pulleys then release the ACL to get the belt into correct position UNDER the Roller Tensioner Pulley. An image search for "HS520 Belt" should reveal a blow-up photo so you can identify these parts. FINALLY, with the drive belt in position, replace the metal cover and four bolts. When our engine ran but the auger would not turn, we opened the case just to confirm the drive belt was broken. Since the belt was intact, we were quickly back to snow-removal. The repair shop had estimated up to two hours labor and a one-week turnaround for what took us ten minutes--less time than the drive to the repair shop. We have since ordered a spare belt. Good luck.
put the belt on the bottom pully then on the top engine shaft then put both parts of the belt under the belt tension then the belt tensioner should be on the top of both part (strips) of the belt.
Bring it to the shop