Can the balance shafts be removed with the engine and crank still in the car? I am not wanting to remove them for good, just check the oil passages (if there are any) for them. After finding my pistons' oil return holes plugged I am wondering how the condition of the front case might be. Any oil passages there that might get plugged like the ones in the pistons? How often do the oil gears need to be checked or replaced? Can they be checked with engine in place? Is this a good time to remove the front case? What all should I check now that I have the front apart for a tbelt replace? I have new wpump, belt tensioner, and 3 pulleys to go on.