The front crankshaft seal is leaking on my timing chain cover. Can i replace this seal just by pulling the crank hub off or does the timing chain cover need to come off? Thanks

 

The timing cover does not have to be removed. Mark the position of the hub to crank before you remove the hub, so you can put it back on in the same position.

 

Great, that is what i was hoping. Thanks

 

Why do you have to mark the hub? What happens if I get a keyed hub?

 

If you mark the hub relation to the crank, then the pointer position will be maintained when you reinstall the hub. It is useful for setting valves and also to maintain balance if your pulley happens to have any balancing weights in the little holes (most don't).

If you go keyed, it can only go on one way.