The Coal Authority has taken responsibility for the site and the repair works will take between 6 to 8 weeks to complete.
Only a 6 metre deep hole is visible at the road surface, but this leads to the shaft which goes down a further 56 metres to a total depth of 62 metres.
Work began last week with stone, pressurised grouting and a concrete plug being needed to stabilise the ground. Once the shaft is filled, work will begin on reconstructing the road.
Tim Marples, Head of Public Safety and Subsidence for the Coal Authority, said that work to repair the collapse in Kilbowie Road has already begun.
He added: The unrecorded shaft at Kilbowie Road is one of our top operational priorities and our prime concern is the safety of the public.
Our engineers have designed a solution to safely fill the shaft and repair the road and were working with West Dunbartonshire Council and the utility companies on our proposals.
This particular repair is complicated by the exposed utility services within the 62 metre deep void, which were working to protect.
From our experience, the work will take between 6 to 8 weeks to complete and cost in the region of 250,000.
Our aim is get the road re-opened as soon as possible to minimise the impact on local residents and traffic. We apologise for the inconvenience and disruption caused presently and during the forthcoming works.