What have you (or...ahem...'a friend') broken and how? I have read a lot of threads about fixing various 'common' problems. But what activities do you really need to avoid in order to prevent the problems in the first place? I'm not talking about preventative maintenance, I'm talking about bad driving or repair habits. Example: What is a sure way to break a birfield? Answer 1: I read on the 40's forum on a post from TORSLINNING, ''...but I do admit to the blunder of backing up and turning at the same time in 4 wheel drive.'' I didn't know this was a blunder. It would be good to know so I can avoid it. Does it apply to the 80's? Obviously they are full-time, but what about when they are locked? Example: Knock sensor - don't whack it when changing the phh. Some things I would like to know, add your own: 1. What is a sure way to speed your head gasket on it's way to failure? 2. What DON'T you do if you want to keep your lockers from breaking/wearing out prematurely? 3. What constitutes real abuse to a factory CDL? 4. What ruins your sun roof?