After reviewing your files, here's what I think I've figured out and what still has me confused.
First, as I understand it, the MD3B crankshaft has a total of 7 journals. Three of the journals are for the pistons (Big end bearing kits - 3x 875491). While 4 are for the Main Bearings 2x 875483 & 2x 875484. Do I have that correct?
Second, part of my confusion is that the parts drawing on the Volvo online parts store (see earlier post) makes it look like #8 (875483) is the top half while #9 (875484) is the bottom half of a set. If that was true, then 2 of each would mean I only have 2 main bearing sets. However, when I do a Google image search for these parts, each is shown as a complete top & bottom set. If that’s true, then #8 is a set and #9 is another set and I have 2 of each which means I have my 4 main bearings sets. Do I have that correct?
Third, I am confused by the two parts each labeled #10 (897223 - Bearing Front & 807497 - Bearing Cap Rear). Again, the drawing makes it look like one is top and one is bottom and that they are carriers for #8 & #9. Yet again, when I search for images, I find they are shown as a complete top & bottom set. Additionally, the description leads me to think that one goes on the front of the crank while the other goes at the rear. Given that the bearing are what wears out, the bearing caps do not normally need replacing. Do I have that correct?
All that said, I’m still at a loss to identify the bearing-looking part to which #6 is pointing. Yes, I know #6 is labeled as a “Seal Ring” but what is the collar in the picture? Is it a collar or bearing that is placed on the front end of the crankshaft or a bearing that is pressed into bearing sealing cover? Looking at the MD2B Engine Block (
http://www.volvopentastore.com/Cylinder ... _id.770516 ). I’m wondering how closely this would match the MD3B. The MD2B drawing shows a “Bearing Cover” (#14) whereas the MD3B does not but, it does show a sealing ring (#28).
Any guidance or advice be greatly appreciated.