I have a leak at the front cover on my truck and all the repair manuals I have state the cylinder head has to be removed to replace the timing covet is this true and is the another way? Is ther anyway to seal it from the outside?

 

you can be real careful and remove everything but the head and gently pull the timing cover down being very carfull of the HG but you risk a blown head gasket down the road. i didn't pull the head and neither did a Friend of mine when we did our timing chains i haven't put many miles on mine yet but my friend put about 15k on his and seems to be doing good.

BTW its a good idea to do the timing chain, steel guides and tensioner while you have it off