Hello Prius Chat members, I am fully involved with a DIY cylindar head gasket repair. I have the head back from a machine shop and it all looks pretty good. It's pretty eash to tell when the crank is TDC. But, there is not much information on this smaller chain. Many of the videos do not even pay attention to the relative position. There is one post on prius chat that which refers to the reationship. I have rotated the engine not several times and have the small dot alligned on the lower gear and the tooth is very close on the upper. maybe half a tooth off. There does seem to be a small triaangle stamped on the large gear with the holes. A stamp like a small triangle which is perfectly alligned with the top link. Question. Must the valve train be in specific time with the lower for balance purposes? Is my position correct. Some have mentioned that every nine turns of the crank is when you get both yellow marks aligning on both sprockets. I believe the larger sprocket with the sqared off teeth if for crankshaft position ? BTW, I did not disasssemble any part of this lower assembly. Finally, because the chain is on I can's see and marks on the upper inner sprocket. Just the triange mentioned . I'm guessing this is correct. Many thanks to anyone with posses these details. Hirsh
Last link in my signature is the full engine section from Repair Manual; might help. (on a phone turn it landscape to see signatures)
Wondering why on earth the oil pump needs to be timed has been kind of a running gag around here for a while. As far as I can tell, nobody knows. But there are marks, so if you do it right, they look like this: "There's yer problem, buddy ... the oil timing was off!" No: that's every nine times you see the painted chain links go by. That's the same as seventy turns of the crank (or thirty-five turns of the camshafts). And that's for the valve timing chain. I don't know that anyone has worked out how often the oil chain marks line up. If somebody wanted to, it'd just be a matter of doing the math.
