Update, 1pm: The Superload is on the move and will continue it's journey to Mortlake today.
Traffic delays are expected along the Princes Hwy towards Mortlake, also at McKinnons Bridge Road and the Terang-Mortlake Road.
Earlier: A 600-tonne, 100-metre-long, five-metre wide superload has broken down, blocking the Camperdown-Cobden Road in both directions.
The superload was carrying a generator from the Port of Geelong to Mortlake, leaving on Sunday night with plans to conclude the journey about 9am Wednesday.
But the vehicle broke down on the Camperdown-Cobden Road about 6.30am on Wednesday, blocking the road in both directions between Cemetery Road and Naroghid Road.
It was initially believed the superload had blown a gear box but a Department of Transport spokesman later confirmed it was not a mechanical issue.
The spokesman said the superload was stuck on a hill due to a traction problem following overnight ran.
"They've had to organise another prime mover in to give it that extra nudge," he said.
"They are also making sure all the drivers and crew have had their required rest time as they've obviously gone into a bit of overtime.
"The journey will resume once they are satisfied all those boxes have been ticked."
Diversions are currently in place and motorists are advised to consider alternatives, including Naroghid Road and Cross Forest Road around the closure.
Motorists should allow extra time.
The spokesman said there was no indication of when the road would reopen.
He said the superload had another 30 kilometers, or about two hours, to go before it reached Mortlake.
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