Clues on the White Album, the repeated "Number 9" backwards is "Turn Me On, Dead Man"
Before on A Day In The life John says "I'd Love to turn you on"
There is some mumbling that sounds like John and Yoko right after the very abrupt ending of I'm So Tired and before the beginning of the next song, Blackbird. This passage has no english interpretation when played forwards.
However, when played backwards, you can hear John say, "Paul is a dead man. Miss him. Miss him. MISS HIM!"
This is again doubly eerie, in that this backwards message again mentions the phrase "dead man", and that the very next line on the record, sung by Paul, "Blackbird singing in the dead of night", also mentions death.