McKenzie was been appointed head coach following the British & Irish Lions' 2-1 Test series triumph Down Under.
Eales was part of one of Australia's greatest eras between 1997 and 2001, a period in which the men in green and gold won the World Cup, Tri-Nations and defeated the Lions.
The former second-row refused to speculate over what McKenzie could achieve at the helm but reckons the players can define a new era.
"It's really hard to compare and say 'will it be like this, will it be like that?'," said Eales.
"They've just got to look and say 'this is our own time, this is our own era', and then create their own history. It's not about what's happened before the 17th of August this year when they play the Bledisloe, it's about what happens after that."
ACT Brumbies face the Chiefs in the Super Rugby final this weekend and Eales reckons a victory could have a knock-on affect on the Wallabies.
There has been little success in Australian rugby since winning the 2011 Tri Nations title, just weeks after the Queensland Reds were crowned Super Rugby kings.
"Hopefully, after this weekend we'll have the Brumbies and the Reds who have tasted Super Rugby success and that's up against the best of the southern hemisphere. That has to build confidence when you can do that," added Eales.
"The All Blacks are the best team in the world. They've been very consistent over a long period of time," Eales said. "It'll be hard but they'll be in there fighting."