can any 1 help asap jag s type 3.0v6 auto gearbox knocking

[jagman2012]

i have recently purchased a s type jaguar in imaculate condition having thousands of pounds in bills including 3k for a new autobox,the car runs smooth as hell and is gorgous to drive however when i start it up when its cold in park postion i hear i rattle i looked under it and it was coming from the gearbox i could see inside the box which i think was the torque converter rattling bk and forward abit but when its in drive it doesnt do it is this normal

[Tony Payne]

I have just bought an S type 1999, and intend to convert it to LPG. Any useful comments would be great if you have the conversion experience??.