Timing Belt change question
#1
Intermediate
Thread Starter
Timing Belt change question
In the process of changing the timing belt ('05 6MT 150k miles). Have the dreaded crank bolt removed (that's another story if anyone wants to hear it). Removed the flywheel and the woodruff key fell out. I put it to the side with the flywheel being careful not to lose it.
After removing the TB covers and other items, I reinstalled the crank bolt to set to TDC. When turning the crank I realized the cams were not turning due to the key being removed. I believe I turned the crank about half a turn (180 degrees) before realizing this. I then put a wrench on the front cam and turned that clockwise until the slots for the key lined up and reinstalled the key. I then turned the crank two more full rotations and set to TDC. Everything seemed to turn smoothly at this point (I have the spark plugs removed).
I am about 98% sure everything is good but I have this slight fear that I got the crank 1 full turn out of timing with the cams. With this being an interference engine, would the crank not turn two full rotations if it was a full rotation off? Any other method to ensure everything is correct at this point?
Thanks for any thoughts on this!
-Brad
After removing the TB covers and other items, I reinstalled the crank bolt to set to TDC. When turning the crank I realized the cams were not turning due to the key being removed. I believe I turned the crank about half a turn (180 degrees) before realizing this. I then put a wrench on the front cam and turned that clockwise until the slots for the key lined up and reinstalled the key. I then turned the crank two more full rotations and set to TDC. Everything seemed to turn smoothly at this point (I have the spark plugs removed).
I am about 98% sure everything is good but I have this slight fear that I got the crank 1 full turn out of timing with the cams. With this being an interference engine, would the crank not turn two full rotations if it was a full rotation off? Any other method to ensure everything is correct at this point?
Thanks for any thoughts on this!
-Brad
#2
Suzuka Master
iTrader: (1)
Unfortunately, if you want certainty to alleviate your 'slight fear', that is only going to be achieved at the cost of doing extra work.
In addition, If you decide to do this, you will have to remove the TB and press the tensioner piston back and re-pin it, if you have already replaced with new and pulled the pin.
Remove the front & rear valve covers, then loosen the 12mm bolts on the Intake and Exhaust valve rocker arm shafts. This will move all of the valves 'up', and out of the way of the pistons. You have to make sure the rocker arm shafts are good and loose to relieve valve tension in order to achieve this.
Reposition the front and rear cam gears to their respective TDC locations.
Then insert / position the timing belt drive pulley & 'key'. Rotate the crankshaft clockwise slowly to bring the TDC arrow on the TB drive pulley in line with the TDC pointer on the oil pump case. Your crankshaft and cams should be in time, and at TDC, at this time.
Then carefully tighten and torque down the 12mm bolts on the Intake & Exhaust valve rocker arm shafts. Paying attention to the tightening sequence outlined in the Helms. As you are tightening the rocker shaft bolts, monitor the cam pulley's so that they do not move from their TDC position.
Reinstall the TB and pull the pin. Rotate the crankshaft clockwise and monitor that the timing marks align as they should.
Good Luck!
The following 2 users liked this post by zeta:
firebolt (04-23-2020),
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#3
You most likely would notice that something gives additional resistance when cranking the engine. Especially with plugs removed.
With some valves open, it shouldn't be possible to rotate crankshaft 360, and even if you did rotate it 360, then nothing in timing changed. You know, since 360 is full rotation and you are technically back where you started.
So if all marks are correct, and you rotate the engine until cams do full 360, and everything still lines up, and there is no unusual resistance, then you should be good.
With some valves open, it shouldn't be possible to rotate crankshaft 360, and even if you did rotate it 360, then nothing in timing changed. You know, since 360 is full rotation and you are technically back where you started.
So if all marks are correct, and you rotate the engine until cams do full 360, and everything still lines up, and there is no unusual resistance, then you should be good.
The following 2 users liked this post by peter6:
Acura TL Builder (04-16-2020),
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The following 2 users liked this post by justnspace:
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zeta (04-16-2020)
#7
Intermediate
Thread Starter
Thanks for all the feedback. Before removing the old belt I had everything lined up ( crank and both cams at TDC based on markings) and cranked it over twice and it all lined back up. I'm feel much better after thinking about this that all is good.
Just took off old belt, replaced WP and TB tensioner and about to install new belt. Everything is back on track!
Just took off old belt, replaced WP and TB tensioner and about to install new belt. Everything is back on track!
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#8
Suzuka Master
iTrader: (1)
For posterity's sake, should anyone need to reference the loosening and tightening sequence of the camshaft holder bolts, please refer to the attachment.
This is from a CL-S Helms and should not vary to much from the 3G TL process.
This is from a CL-S Helms and should not vary to much from the 3G TL process.
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#9
#10
Intermediate
Thread Starter
Success! Got everything back together last night and started it up. Everything is working as it should.
Thanks again for the replies. Nice to have the extra vote of confidence with this job.
Now onto changing the MT fluid that has not been replaced in many years.
Thanks again for the replies. Nice to have the extra vote of confidence with this job.
Now onto changing the MT fluid that has not been replaced in many years.
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drtjnky
2G TL (1999-2003)
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09-09-2019 01:01 PM