Maintenance crews have spent the last few days felling trees and clearing away soil after landslips blocked the road at Macquarie Pass.
There is a chance of more landslips, given a downpour is predicted for Thursday.
The pass was closed after being hit hard by the weekend's heavy rains.
"There is a lot of spoil and rocks on the road requiring on-going clean-up using excavators, skid-steers and trucks," a Transport for NSW spokeswoman said.
"Crews continue to work around the clock on to clear debris and dangerous trees, contain embankments, and complete road surface repairs.
"Work is expected to be completed in the next few days, weather permitting."
During the closure motorists should use Picton Road or the Princes Motorway as alternate routes.