a couple of tranny vans at work are on 350k on original engine but new gearboxes.theres a sprinter on 410k but it has had a new engine.ive had a tranny van with 260k on it.the one ive got now has been round the clock(95 mreg with mondeo dash so thats 1000000 miles)dont know how many engines/gearboxes/back axles its had though