Crazy,
The mains are not difficult, there just different. They are held in the same way as the rod bearings are, a little offset on one side of each half. There is a little mating indentation on each half of the bearing journal that this offset fits into. This bump and dimple is how the bearing is kept from spinning in its journal.
To get the old bearing out of the block half of the journal without removing the crank, you have to push the bearing on the side without the dimple with a small flexible blade. Something that wont scratch the crank or dig into block. I used to use a small feeler gauge that I had polished with steel wool to make it smooth. Now I use small pieces of plastic that I cut out of,....are you ready for this...car battery handles. They're soft and flexible, they just have to be thinner than the bearing so it wont get stuck.
Tap the bearing remover (part number: M Mouse 1279) with a small hammer handle till it rotates around the crank enough to grab the dimpled side with a mechanics pick. If it feels stuck, it's usually because of oil adhesion ( or co-hesion, I can never remember which it is). It might also help to loosen adjacent journals to help the crank sag a bit.
Things to keep in mind:
The middle bearing has individual thrust plates that must be replaced EXACTLY the same as the way the old ones were. You can use a heavy grease on the back side of them to hold them on the journal during assembly. They have grooves in them that put a film of oil on the contacting surfaces of the thrust bearing. The thrust bearing is what keeps the crank journals centered under each rod. Very Important!!
The crank main journal bolts must be tightened in stages AND the right sequence. Use a good torque wrench.
Use engine assembly grease on all bearing surfaces or STP oil treatment. When you refill the oil pan with new oil it will take a few seconds to recharge all the passages so the grease helps during this time. You should get in the habit of pre-charging your oil lines anytime you have drained your engine.
Make sure you use a new gasket or gasket maker on all things like oil pick-up tube that you have to disconnect for this job. Your oil pump cannot make good pressure without a sealed tight pick-up tube.
Good luck, and sorry I was so long winded.
Tom
