I had the same prob on my Rancher (1866) after installing new cork pads. Fixed it by turning the nut on the actuating rod ... its on the RHS under the seat. Was a very cumbersome job as not much clearance for the spanner, from memory I turned the nut so it moved towards the front of mower. I still get a tiny bit of squeal before the clutch bites but some initial slippage is to be expected. Constant squealing means that you have slippage and will eventually glaze or burn out the cork. I would not recommend any lubricants (or belt grip which I once tried), these things are just finicky to set up.
hope this is of some help
