Toyota 2UZ-FE Timing Belt Marks 4.7L

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MarkMarzluf

Guest
Lewis said:
None as long as one of the cams doesn't roll over. This is an interference engine and when at TDC, the cam lobe is under tension by the valve spring. If one of the the cams gets moved and turns, a valve could come into contact with a piston and bend.
The 'T" marks are off TDC, so the cams aren't under tension.
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I'm not an expert, but have done this job a few times. The "rollover" of the cams is certainly due to valve spring tension. That tension is due to a valve being opened. At TDC, the valves that are open, are not near the top of its piston. (intake open on down stroke, exhaust open on an up stroke) regardless, the rolling back (or forward) of the cam CLOSES the valves that are open, not the reverse.

Correct me if I'm wrong.
 
Lewis

Lewis

Moderator
Staff member
MarkMarzluf said:
I'm not an expert, but have done this job a few times. The "rollover" of the cams is certainly due to valve spring tension. That tension is due to a valve being opened. At TDC, the valves that are open, are not near the top of its piston. (intake open on down stroke, exhaust open on an up stroke) regardless, the rolling back (or forward) of the cam CLOSES the valves that are open, not the reverse.

Correct me if I'm wrong.
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I had to go back and reread my post, I think what I should have said and more importantly is that when the engine is off of TDC like the instructions want, the pistons are down (not at TDC) and therefore the valves cant come into contact with them. That's more important that the cams being or not being under tension.

If the job was performed at TDC and the cam accidentally rotated, under much force mind you, the valves could easily come in contact with the pistons.
 
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Mindyalberto89

Guest
I have a 04 toyota sequoia, the problem is it was down due to the fact that the water pump went out. So the pulley of the water pump wasn't spinning causing the timing belt to melt off and caused my vehicle to be down. So vehicle was cranked over and over not knowing that the belt was damaged already. We figured that valves may have been bent since it was cranked when belt was damaged. Here's the thing heads were brought to the machine shop without the cams in them due to needing clearance on them in order for them to be shaved with the ports for valves. Now I just need to know about the cams alignment when reinstalling them back. Also the machine shop said that valves weren't bent when he changed the valve seals??? Just need help now engine has been put back together now but it won't stay on when cranked any longer then 5 seconds or when given gas it'll die. What I'm getting of her is a weak idle when started. Might timing be off??? Don't know please help. Thank you
 
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spacekase

New Member
Im glad I found this thread on the web. Im in the same boat of TDC ot ATDC? Everything in this thread just makes so much more sense, however, like a previous posted above noted. Aisin instructions, even the downloads I got from Toyota.tech for my 2006 GX470 says to use TDC (but slightly off 1 tooth, 1/2 tooth) off of TDC. I guess thats to keep the cam from being under tension. But why the heck do they all completely ignore the "T" (ATDC)...???

Im ready to do this job but I want to make certain that using ATDC for the 4.7 vvt-i motor is okay. I havent seen anything that says it is or isnt pertaining to this specific year 4.7.

Any feedback would be much appreciated so I can get this show on the road.

Thanks!!!!
 
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Isaiah

New Member
Just finished doing a water pump and timing belt on my dads truck. I noticed while lining the marks up prior to removing the belt that the R cam was off by a tooth, and confirmed this while trying to put the new belt on.

Picture showing how the new belt wouldn't line up due to it being off a tooth
Right-Cam-Off.jpg


I decided to go ahead and move the cam one tooth to make it line up, and everything slid into place perfectly after that.
Right-cam-Fixed.jpg

Left-cam-on.jpg

Crank-on.jpg


Put it all back together and it runs perfectly, I'm assuming I made the right choice but I wanted to see if anyone else had run into this similar issue.
 
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CreativePaul

Guest
Lewis said:

The following thread will explain how we set up the Toyota 2UZ-FE Timing Belt marks when replacing the timing belt.

The first tip is that we set the timing marks in place with the engine past/after TDC and not on TDC. This is because this engine is an interference engine and it will help prevent the valve damage if the cam or crank were to slip and rotate.

Another tip is that you know which Bank is #1 and which Bank is #2. Here is a reference...

2UZ%20Engine2-L.jpg



The first pictures I will show are of the timing belts marks as we are disassembling the front covers just so we can get a reference of the marks we will be using. Notice that the cam gear marks don't line up exactly. This is due to the old timing belt stretching just a bit over time. '

These first marks are where you want to line up the crank pulley....

IMG_2073_cleaned-L.jpg


IMG_2075_cleaned2-L.jpg



Now lets see the Bank 1 and Bank 2 marks. Again, the lines will not be perfect as the original timing belt has stretched just a bit.

Bank 1 marks.....

IMG_2076_cleaned2-L.jpg



Bank 2 marks....

IMG_2078_cleaned2-L.jpg




Now lets look at setting up the new timing belt and using the same marks as before. The new OEM Toyota timing belt will come with it's own marks on it. These marks serve as a Poka-yoke so that you can't get the marks lined up wrong. There is another mark that can be seen but just remember we use the "T" mark for Timing Belt.

Also note that Bank 1 is labeled as the L-Cam and Bank 2 is the R-Cam. The arrows also point to the front of the vehicle.

Here are the Bank 1 marks....

IMG_2081_cleaned2-L.jpg


IMG_2083_cleaned2-L.jpg



Now for the Bank 2 marks....

IMG_2079_cleaned2-L.jpg


IMG_2080_cleaned2-L.jpg


Last but not least, let's see the crank gear timing marks....

IMG_2085_cleaned2-L.jpg


IMG_2088_cleaned-L.jpg


Well that about wraps this one up. This post was just designed to show you how we did this job lining up the timing belt marks. Please consult a Toyota Dealer and/or the Toyota repair website www.techinfo.toyota.com for more information.

***** But what about the other marks that can be seen behind the timing belt?

These marks are for setting the engine up at TDC (Top Dead Center) and not for replacing the timing belt. Here are a few pics showing the TDC marks...

IMG_2091_cleaned2-L.jpg


IMG_2090_cleaned2-L.jpg


IMG_2094_cleaned2-L.jpg


IMG_2093_cleaned2-L.jpg


If you'd like to see how this job is performed then here is a Toyota Master Tech at work...

​
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Is this the same position specs for a 2004 4.7 V8 Tundra?
 
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Lawrence

Guest
I followed the instructions for removing/replacing my 03 sequoia timing belt (scheduled maintenance). Upon installation of the new belt to the left side Cam pulley it moved from the “T” position as I was installing the belt to the right cam pulley

I attempted to move the left cam back to the “T” position by hand, however it moved to the left behind the “T” and TDC timing marks.

I was advised to remove all 8 spark plugs and turn the crank back to TDC then I would be able to move the left cam back to the “T”. However I wasn’t able to move it forward to the “T” by hand and haven’t tried to use a 17mm on the pulley nut as recommended until I get confirmation of this procedure. I’ve been looking for a pulley positioning holder tool without any success, because if this is the correct procedure I don’t want it to move upon installing the belt.

Please advise if you experienced this and what process and/or tools required for correcting alignment.
 
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