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Millermatic 211 and 1/4 diamond point bits with a die grinder. One tap of the trigger, then fit the key, grind and refit until it sat straight, repeat.
Tedious, not fun, never your first choice if you can avoid it, but beats the living crap out of scrapping the engine or selling for parts and buying something else. I worked in a motorcycle machine shop for a while mostly doing cylinder heads, but welding and shaping was fundamental to fixing any number of things that got trashed in a wreck. Looking good for sure.
All good. Sprocket tapped on tightly, just like stock. Filled the keyhole with Loctite 660 as well. See below for a few videos on the timing chain process and that pesky tensioner.
^^ Great progress... Thanks for sharing the videos and especially that pesky tensioner on drivers side.
Thinking about mine that makes an inconsistent flap slap tap on fresh oil only.. Trying to piece together in my brain why the tensioner is causing what now I think to be chain noise on the guide slide.
I have never seen these parts dismantled in detail
All good. Sprocket tapped on tightly, just like stock. Filled the keyhole with Loctite 660 as well. See below for a few videos on the timing chain process and that pesky tensioner.
Thanks for the videos, definitely something not well with the tensioner. Yamaha has been using designs like that for a very, very long time in motorcycle cam chains - my 1984 FJ1100 cam chain tensioner was very similar except it used a mechanical spring instead of oil pressure, and once the ratchet set, it never backed off. But most motorcycles are way shorter from the crank to the cams and they normally have one cam chain, not two or four. You noticed wear on the crank sprockets? What oil were you running? That's worrisome because an oil mist environment is ideal for chain service life, and sprockets don't normally wear out until the chain stretches too much. Drive chains on bikes of all kinds will kill the sprockets if you run them too long, but if you replace them on time, the sprockets last almost forever.
Did you wrap the new chains around the cam sprockets and check for slack? Just curious...I will be doing that with mine, but I am approaching 180k miles too.
Oil I have no idea. I got the car with 125k on it, it has 126k now. I barely put 500 miles on it before all this happened after the SC install.
According to lexus service history it had regular oil changes of pennzoil ultra or platinum full synthetic its whole life. The keyway issue might have contributed to some sprocket wear with everything slapping around in there for a short period of time, who knows.
I didn't compare old chain to new, but I'll measure the old chains per TIS and see how they compare to the service limit.
Chains are out of spec by a few mm. I'm sure the tensioners probably would have kept things fine for quite awhile as there is enough room in there to tighten things up more as the chain wears, but Toyota suggests that these should not go back in the car. Timing gear is just at the minimum spec.
Congrats on the repair. You saved me having to make videos of the timing chain replacement too. I will be replacing my tensioners and chains at 180k miles when I planned to do a valve lash inspection anyway. It's actually going to include resealing the valley plate too. After the wear you documented, I think I need to buy a new sprocket for the crank as well. It's really disappointing the chains wore beyond limits with your mileage as low as it is. That's never a good thing. I wonder if it would be better with double row chains...
Also, big congrats on the keyway repair. It didn't look horrible to me, and I'm really glad to see it worked out as well. I know I would have fixed it too. Not bad enough to scrap an engine.
I didn't understand why TIS said to do the valve inspection after doing the chains you'd think it would be easier with cams loose, but it makes sense so the chains can hold the cams at various points. Luckily the dealer did my valley plate before I bought the car. Are you going to do it all at once or knock out the valley plate first and get the top end put back together?
I didn't understand why TIS said to do the valve inspection after doing the chains you'd think it would be easier with cams loose, but it makes sense so the chains can hold the cams at various points. Luckily the dealer did my valley plate before I bought the car. Are you going to do it all at once or knock out the valley plate first and get the top end put back together?
Precisely correct. The instructions tell you to position the cams a certain way, check the following valves, then rotate the crank 360 degrees and do the second batch. Keeps it simple. I plan to check mine, determine if any adjustments are needed (of course I'm going to run it very hard and pull some water through to clean up as much carbon as I can so I don't have any valves too loose from carbon build up) and if they are needed, I'll pull the cams with the chains already off because it will be easy for sure.
It'll be a weekend project with some long hours no doubt. Honestly the part I hate the most is getting everything cleaned up for reassembly. It's really tedious getting all the old sealant off and everything cleaned up pretty for reassembly.
Precisely correct. The instructions tell you to position the cams a certain way, check the following valves, then rotate the crank 360 degrees and do the second batch. Keeps it simple. I plan to check mine, determine if any adjustments are needed (of course I'm going to run it very hard and pull some water through to clean up as much carbon as I can so I don't have any valves too loose from carbon build up) and if they are needed, I'll pull the cams with the chains already off because it will be easy for sure.
It'll be a weekend project with some long hours no doubt. Honestly the part I hate the most is getting everything cleaned up for reassembly. It's really tedious getting all the old sealant off and everything cleaned up pretty for reassembly.
Timing cover sealant actually wasn't that bad. Pretty thin from the factory. Bigger parts come off nice with a razor blade, the rest wipes clean with brake cleaner/acetone.
04-06-20, 09:35 AM
