To my knowledge you do not need the cover. Top, line the mark up with the mark below it. Bottom will sit at 12 noon. Maybe someone else has a more involved answer but I just done it on an 86 2.3L ranger and it runs fine.
They are on the inner timing belt cover.
The engine timing chain cover
On a 2003 Ford Ranger : The 2.3 litre Dual Over Head Cam four cylinder engine , and the V6 engine(s) use a timing chain ( or chains ) If you mean the timing chain cover is leaking oil , that should be repaired ( P.S. I'm not a mechanic / technician )
Timing chains are usually located on the front of the engine, behind the drive belts, under the timing cover. You can't see them without partially dissasembling the engine.
The water pump is at the bottom of the engine, bolted on the back side of the timing cover. The pump can be removed without remove the timing cover.
Small pinhead size holes behind the water pump,eventually breakthrough the cover and voila you get coolant mixing with engine oil.
front timing cover
its mounted on the oil pump assembly behind the inner timing belt cover. that's on a 2.3L engine
The crankshaft position sensor is located at the front of the engine close to the crankshaft damper
The timing chain cover on a 4.6L is the whole front of the engine. drl
pin the engine on the flywheel. line the timing mark on the cam gear with the timing mark located on the timing cover. the mark on the cover is located at the top and is just a bump formed in the cover.
Remove the valve cover