If you have made sure that is your problem it is best to pull the pan and the front off the engine. The pan will be full of bits of timing gear as well as the
oil pick up.
Make sure you check to be sure the chain has jumped before you dig in. Another thing you can do to check for "Play" in the timing set is move the crank back and forth and see how much free spin you get before you fell the cam start to turn. If the chain is in good shape it will not move much if the chain set is bad or going bad it can move up to and inch or more side to side.