Flex plate

Hi all think I have to do the flex plate 2questions should I change the t/c while I have it apart . I thinking when the t/c gives up it ruins the gear box so by changing it would I prolong the life of the gear box? And does any body know the best place to place a heavy duty jack under the gear box for the best balance cheers joe.symptoms rattle when not in gear more when cold no judder yet and gear changes are still smooth changed filter a while back small amount of filing on magnet but other than that all still works fine.

Bump Hey opinions please its an auto obviously 1999 dse there all the same gearboxes alltho I have read in rave up to 1998 then they changed slightly longer from 1999 onwards is this true?I hear there is a Zf4HP22EH and Zf4HP24EH what's the difference And last thing is the dse flex plate the same as the 4.0 and 4.6 as I can only find listing for those only thanks joe