The Wallabies spring tour of Europe ended with a thud, losing to England 26-17 and the defeat was made harder to swallow following an absolute scrum annihilation by the hosts.

It's not the first time the Wallabies big men have struggled in London, dismantled on the tour of 2005, which resulted in coach Eddie Jones being sacked.

The scrum crumbled again under immense pressure and it looms as the weakest part of the Wallabies' game before the World Cup.

Cheika revealed he had spoken to IRB referees bosses last week to ensure the officials did not have a preconceived idea about the Wallabies' set piece.

And the coach believes the Wallabies may have to start fighting illegal tactics with their own scrum hijinks, declaring: "Maybe we're just too honest".

"We need to change some things, technique and strategy," Cheika said.

"Perhaps a bit more wheeling [the scrum around] or something because that seems to be accepted. Maybe we are just a little bit too honest in the scrum … there are some personnel we are going to look at as well."

England scored both of their tries off the back of strong scrum work, with No. 8 Ben Morgan benefiting on both occasions.

At times the Wallabies forwards matched England. But too often the power fell away and England used the set-piece as a destructive weapon.

The scrum is the Wallabies' Achilles' heel and there's no quick fix on the horizon. They conceded a penalty try against Wales in the first Test of the tour and were inconsistent in all games.

The scrum disaster in London prompted England's World Cup winning coach Sir Clive Woodward to write off Australia's chance of a revival.

"To know that the England team dismantled the Australian forward pack at set-piece time, I don't think Australia can fix that in time for the World Cup. It was unbelievable, it's a huge statement for England."

Cheika went through the "correct channels" to contact IRB referees last week.

Cheika also intends to add new personnel to the front-row stocks and potentially hold sessions with props from around Australia during the Super Rugby season.

"I tried to liaise with the IRB referees boss, I probably didn't get the answers I was looking for," Cheika said.

"This is not a straight pushing issue, there are two packs of 800-odd kilograms, we can't be that badly prepared physically that we're getting out-pushed.

"There's certainly a stigma about our scrum. They [the IRB] have said there isn't. We're the only ones who can change it because if we keep doing the same thing we'll get the same result.

"I've got some ideas … We got five penalties against us and in two of those we were in bad positions. But the others it was being spun … we should just do the wrong thing as well.

"The outcome has been consistently inconsistent in recent years. It's never been a strength, but we have to turn it into one because if we do it can hurt a lot of people."

The Wallabies had the same starting front row - James Slipper, Saia Faingaa and Sekope Kepu - in their four Tests. Stephen Moore and Tatafu Polota-Nau will step back into the hooker duties while Brumbies prop Scott Sio could get a call up.

Inside centre Matt Toomua said the back line had to take some responsibility for the set-piece pressure after dropping too much ball and putting the scrum in bad positions.

"The guys take a lot of pride in it and they're not stoked about the penalties," Toomua said.

"As a back, we probably did the guys no favours in turning the ball over too much. We need to hold the ball and be mindful of that."