Well against my better judgment, I tried again. This time I put a pipe wrench on the crank pulley and was finally able to crack that crank bolt.
So I carefully pried off the timing cover. Care must be taken at the crank while removing as a bearing gear there is close.
The docs say to turn the crank CCW to set timing, and I'd assumed this is to allow for gear lash -- but this doesn't make sense. It's the
crankshaft which drives everything and it turns CW. So I don't understand why docs say manually turn CCW for timing. Are they confused?
I found the mark on the crank gear and wiped the oil off, but the -mark- came off instead, just as with the fuel pump gear! Is this a kindergarten engine here? So I marked it with a Sharpie.
Now if you look carefully you'll notice three marks stamped in the gear in a triangle,
one tooth away from the mark. Why wouldn't the stamped marks be TDC? Or is it?
Second thing you'll notice in this picture is how loose the crank teeth are in relation to the large idler. This is disturbing.
So I turned the crank CCW until the camshaft gear met the idler gear exactly, as in the drawing above. This is where the crank gear landed:
Yep, it's off. The cam and crank gear are both supposed to be right at the idler gear... but they are NOT. I couldn't believe it so I turned the crank for two more full rotations of the cam gear, and same result every time. This is where the crank gear ends up.
Where do I feel max compression? Here:
Right where the crank should be, whether for 1-4 or 2-3, but the cam gear is definitely OFF. Or -is- it? Zoom in on the picture and there are two stamped dots on the cam gear which line up correctly at this position. Are the yellow marks just bogus?
None of my pics captured the whole cam gear but it appears to have about 4x the number of teeth as the crank gear, which would make sense for a 4-stroke engine.
I suspicion at this point that when I went down the 1' ledge with a *bump*, the crank gear teeth slipped, and the engine instantly died. Looks to me like the large idler gear bearing is worn so it is loose?! It appears that the crank gear slipped about 4/5 of a revolution. This would also account for why it won't kick on ether. It would be a miracle if I haven't crashed valves.
How can a 2016 Cat have this kind of problem? Is the bearing/gear replaceable?
Have I crashed valves? Seems to me that I should have -two- compression points in the cam turning cycle, one for 1-4 at TDC and one for 2-3 180 degrees away. I notice only one compression point, where I've shown.
If I have crashed valves for 2-3, is there any sense replacing just them? Could the guides/seals be damaged as well? If so, is there an aftermarket source for rebuilt heads? Or would it be better to have this one rebuilt? I guess I could get valves/guides/seals, etc and provide to a machine shop.
Thoughts? Comments? Criticisms?