how do i find tdc i know nothing about this it's my first diesel need to change my valve cover gaskets i thought i would do a over head while i had my covers off i just don't know how to get tdc all tips and tricks greatly apreciated

 

Funnily enough, I have no idea on our trucks how to find it. But, a trick I used on an old International bus I worked on was to pull and injector, stick a bit if wire down the bore and crank it 'til the wire didn't raise up any further due to the crown of the piston reaching TDC. That's not the most scientific way I guess, but there is always margin for error built in. And besides, the cam lobes are only 30° or 40° of the whole circle, so it's no big deal.
First thing I'd do is check the sticky for a how-to. I know there's some stuff on Youtube also.

 

look in the sticky at the beginnig of the forum for how to set valves finding tdc with timing pin instructions are there. pull a sparkplug and look for piston comming up: