4.7 Timing Question

[dalandshark]

Hey,

I’m doing my first timing belt change ever (for me, and I believe my runner). I have watched several videos and read through forums. There seems to be a lack of clarifying information easily available about timing marks...

What I do know for sure is that the marks where you set the crank and cams depends on the year of the motor. 0 TDC for some, %ATDC for some, and %BTDC for others.

Mine is an 03. I believe it should be at 0 TDC... but then I watched a video and dude did ATDC on an 01... before I watched that video I thought it just depended on vvti or not.

So, what’s the verdict? What is the setting for each year?

It’d be nice to have a thread with this info. I searched and didn’t find one.

 

[BlackWorksInc]

Both these threads go over the marks IIRC:

Guide: V8 Timing belt replacement 2UZ-FE VVT-i (this is a newer and very well written guide)

2UZ-FE R&R T-Belt & Water Pump (this is my very old guide I made long long ago that was a literal representation of the FSM so I used the TDC marks, though we talked about the "T" marks later in the thread.)

But technically it doesn't actually matter. You can use either set of marks and still be in time (i.e. TDC marks on cams and crank, or "T" marks on cam and crank). The "T" marks are just a service position that lessens the chances of the cam rolling over by itself once you've taken the belt off which could possibly cause valvetrain damage if it occurs.

I've done it both ways over the years, the TDC way you have to be conscious not to bump the cams or to hold them with a wrench because they will want to roll on you without the belt on them; the other way is easier and is a service position. So dealer's choice. :noidea:

Hope that helps.

 

[dalandshark]

Hi [MENTION=100496]blackworks[/MENTION] thanks for the info. I have read your thread in the past as I have been planning to do this job for 7 years (but not planning the job for 7 years).. I have watched all the videos as well. I reread the entirety of the threads you linked. I will say that the threads do not definitively answer my question, because I am now convinced there is no answer - but it is definitely discussed a lot.

However , I am going to forget the discrepancies about the service manual and go with the ATDC dot. As you said, you can choose either way. And for me, my marks line up both ways so it shouldn’t matter. The engine was at rest exactly in the ATDC position when I took the covers off so that’s what I’m going to do- and when I’m done it should line up both ways just like it does now.

I think we can count this thread as a short summary that it doesn’t seem to matter - for anyone who stumbles upon it.

 

[4RAAAA]

Thanks for sharing, good to know

 

[dalandshark]

Got it done!

I will not do it again without the crankshaft pulley holding tool. I will also have a small drill cleaning disc/pad available to clean the water pump mating surface - took forever by hand.

Next up is my dads 4.7 tundra with 222,000 on the original belt.

Thanks again [MENTION=100496]blackworks[/MENTION] for your contributions to these forums!

 

[Stephenhermann04]

Clarification

Both these threads go over the marks IIRC:

Guide: V8 Timing belt replacement 2UZ-FE VVT-i (this is a newer and very well written guide)

2UZ-FE R&R T-Belt & Water Pump (this is my very old guide I made long long ago that was a literal representation of the FSM so I used the TDC marks, though we talked about the "T" marks later in the thread.)

But technically it doesn't actually matter. You can use either set of marks and still be in time (i.e. TDC marks on cams and crank, or "T" marks on cam and crank). The "T" marks are just a service position that lessens the chances of the cam rolling over by itself once you've taken the belt off which could possibly cause valvetrain damage if it occurs.


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So if Im reading correctly, on my 2002 Toyota sequoia I can place the marks on the T and take the timing belt off. Then set it to TDC when I reinstall the new one