We had a similar problem with our HSC170, solved by the following:
Remove front lower panel, condenser reservoir and filter.
Remove the exposed metal panel. 4 Screws are underneath, 2 are in the white door surround, others facing you. The panel can then be eased upwards and out of the door surround.
Bottom right corner is the fan housing in two halves. Unclip the top half so this is free.
Release the front fan (clipped to motor) and let this drop down at the front (no need to remove).
Now remove the top half of the housing. This needs some 'jiggling' to get out at the front. Take care with the wiring to the right.
You should now be able to see the two pulleys holding the drive belt.
Apply a small amount of grease (or oil) to the pulley spindle ends. Do not get lubricant on the pulleys or the drive belt.
Rotate the drum by hand to help lubricate the pulley spindles.
Put fan housing back into dryer. Replace fan and then clip housing back into place.
Replace front plate, filter, reservoir and front panel.
Try dryer and I hope this cures the problem for you.
I expect the spindles will need lubricating again every few weeks.
Ian.
Ian McLelland, September 2007