1MZ Cam marks won't align

[dgspencer]

I replaced a blown rear head gasket, and since I was replacing the timing belt, I didn't make any marks on anything. Figured I'd just line up the factory marks upon reassembly. What an IDIOT move that turned out to be! I actually removed both heads and tanked them. So, all cams removed.

Upon reassembly, the front cam gears aligned with the single dot pointing to each other. The knock pin on the end is straight up, and mark on pulley aligns with mark on #3 timing cover. No problem.

The rear is messed up. When the double dots are aligned on the cam gears, the knock pin on the end is pretty much straight down. So the sprocket is upside down, with the mark on the sprocket about 180 degrees off from the mark on the cover. If I rotate the cams so the sprocket/mark is up, the dots on the cam gears are way off.

The weird thing is that aligning the double dots on the gears appears to be correct. This makes the service bolt hole to hold the subgear at the top. If it was in any other pos. you couldn't get the service bolt in. Also, I believe the cam lobes are in correct pos., will have to check that. I can't remember how it came off, didn't take pictures or make marks. Did I mention I am an IDIOT for doing this?

So, how could I get it backwards like this? The sprocket bolt was very tight, big cheater bar...obviously the cam is not twisted, but could the end rotate somehow? What marks do I go by, the double dots on the cam gears, or the notch on the sprocket and timing cover?

This is a '99 1MZ in a Sienna, 60K miles. Please help as I need to get this back on the road so my wife will give me back my Cruiser!

[Axel Kain]

give us some current (problem) pics.!

[Nad1370]

Way off ?

I think your on. As long as you timed the gears on their dots and did not jump while torquing the caps. You should be on regardless what the position of the cam pin is facing.

What I think your looking at is when you rotate the cams so the pin is facing up is that the dots doesn't line up right ?
But if if you rotate it more I think they will line up although the pin won't be facing up anymore. If this is the case. Your fine.
TDC in the right bank(firewall side) is line up through the gear where the T-belt rides on.
Pay no attention where the dots are in this point beacause you timed them already when you dropped the cams.
I know the left bank(radiator side) shows the dots are lined up and pin is up but the right bank is timed differently and doesn't mean it should look like the left bank.

[dgspencer]

That makes more sense to me. I seem to recall when removing the rear cams that the service bolt hole in the gear wasn't accessible when the sprocket mark was aligned. I had to rotate the cams to get the service bolt in. I just don't remember where the gear dots were in relation to the sprocket mark.

Update: I looked a bit further and when the sprocket mark is pointing at the cover mark, the single dots on the cam gears are aligned. That almost sounds right, either the thing is 180 off, they used the wrong gears during assembly, or it is supposed to be that way.

I am going to align the sprocket marks and put the belt on. I'll then rotate the crank a couple of times, and if it looks good I am going to cross my fingers and do a smoke test!

I tried taking some pics, but it was difficult to get the lighting right and they didn't turn out well.

[dgspencer]

Just getting around to a final reply, figure I owe the list that. Thanks for the response, you were right on, as was my install.

I was hung up thinking that the gear dots had to stay aligned when the sprocket marks are lined up with the marks on the timing cover. Wrong.

Just install the cams as specified, with the dots aligning on intake and exhaust gears as they are supposed to.

The timing belt install and sprocket marks is a completely separate procedure, not necessarily related to the dots on the cam gears.

I fired it up and it runs beautifully. I am actually amazed it runs at all, being how I am a shade tree mechanic that hasn't been that deep in this type of motor before. I mean working on a greasy old SBC is one thing, and this is quite another.

Thanks!

[Nad1370]

^^ Glad to here a succesfull job well done .