Redknapp cited crippling knee problems as the primary reasons for his decision to leave Rangers, who were second from bottom in the Premier League table.
But he has now revealed that was not the only issue.
In an interview that will air in full on Saturday, the 68-year-old said the club had descended into a "soap opera".
"I always thought I had everyone pulling with me and suddenly I felt some were and some weren't," he said. "Behind the scenes, I always thought there were one or two people with their own agendas."
In a wide-ranging interview at his home in Poole, Redknapp says:
Redknapp is undergoing rehabilitation on his knees and can now walk and stand without pain.
But the former Tottenham and Portsmouth manager admitted to being "worn down" by incessant rumours around his position as manager at Loftus Road.
He said: "There was talk about Tim Sherwood coming in. QPR was in the paper every day. I've been at lots of other clubs, big clubs as well where you didn't get that.
"That got on my nerves. That was the big problem for me.
"As soon as we lost a few games, it would begin. I always thought there was someone mischievous causing it. I'd never had that before at any club I'd been at.
"I didn't see the teams below us getting the same sort of headlines every other week. It wore me down a little bit."
Academy coach Chris Ramsey took over as boss in February and the Hoops are now two points off safety in the table.