AC/DC bassist Cliff Williams has said he plans to retire after the current tour, becoming the latest member of the high-decibel band to bow out and cloud its future.

"It's been what I've known for the past 40 years, but after this tour I'm backing off of touring and recording," Williams told Gulfshore Life, a magazine about southwestern Florida where the 66-year-old British-born bassist lives.

The Australian-born band plans to close a year and a half of touring on September 30 in Philadelphia with Guns N' Roses legend Axl Rose as their frontman.

Rose joined for a recent European leg after longtime singer Brian Johnson was told by doctors he risked permanent hearing damage if he kept performing.

Malcolm Young, the rhythm guitarist and brother of iconic founder Angus Young, retired before the 2014 "Rock or Bust" album as he suffers dementia.

And drummer Phil Rudd was pushed out after he was arrested on charges of ordering a murder in New Zealand, where he lives.

"Losing Malcolm, the thing with Phil and now with Brian, it's a changed animal. I feel in my gut it's the right thing," he told Gulfshore Life of his retirement.

His departure is the latest question mark over the future of AC/DC, which enjoys a loyal fan base and has not announced plans for after the tour.

Angus Young, known for his trademark schoolboy uniform, remains the key creative force in the guitar-driven band.

Williams joined AC/DC in 1977 after Young grew musically frustrated with original bassist Mark Evans. 

Williams was part of the band for 1980's "Back in Black," which remains one of the top-selling albums of all time.