Hi ,i have a BMW e38 3.0d 2001 ,I have an automatic gearbox and I would like to change it because I have problems when I go back, it doesn't work when I hit the smallest bump, I would like to change it with another gearbox but I don't know what other gearbox it would be compatible (e39 3.0d, x53 3.0d?) which gearbox do I have on the BMW e 38? 5hp or 6hp?