Volvo Repair: flywheel timing sensor, engine alignment, 5 oclock

Question
1989 volvo 740gl wagon (european spec)my quest. is how do set the timing and where do you find this alignment mark ,my main rear seal is leaking the manuals i have research did not show or tell how this is done . does this have anything to do with the engine alignment mark. please send info on this if you can   thanks

Answer
if you have not taken it apart just mark the flywheel when you remove it then you know where it goes.if you have removed it and now have it on wrong.then you need the engine set at top dead center # 1 cylinder then here are 2 pins on the flywheel that align at about just above 3 0clck and the other will be at 5 Oclock.best would be to check a local dealer if possible for copy of picture in manual that shows this.