cbr600rx7

Hey every one. So my new timing belt is being a psi and I want to make sure I am not going crazy.

I am using a Toyota timing belt so things should be simple.

I started by lining up the drive pully and oil pump marks and rotating all the cam marks to the 12 O-clock position. I then lined up all the belt marks for the left and right cams and the CR dot on the crank. The belt seemed very tight on the drivers side. I removed the tensioner pin and rotated the motor by hand probably 3-4 times until the belt rotated all the way around.

This is is when I noticed the timing marks didn't line up with the timing cover or the little dot on the crank. All three are one tooth off is this normal?

scope103

Yes. In gearing, this is called a "hunting pattern." The particular spot on the belt (the dots) line up with a different part of the cogs each time around. Otherwise, a burr on a cog would hit the same spot on the belt each time, shortening its life.

All you care about is that for each two turns of the crank, the three cogs (crank, two cams) line back up to the starting place.

ADVYOTA

No,

The markings should all align (within reason) only way to tell you is to see it. Take a picture if you can.

1. The cams only have 1 rotation while the crank has 2 (to reach TDC).

2. Easiest way to complete the task is to set the cams on TDC first.

3. Remove the #1 spark plug. You can use a compression gauge and a balloon or just the gauge. Look for an up tick in pressure when you have reached TDC on the Crank. The #1 piston should be at the top of the cylinder.

4. Put on the Timing belt, take care not to put so much tension on it when installing that you turn the cams or crank (much less likely). Apply tensioner and call it done.

***This is soooo much easier with an extra set of hands/eyes*** Try to get a buddy, kid or wife to help if possible.

scope103

Sigh ...

cbr600rx7 is talking about the marks ON THE BELT. They're a guide to make it easier to install the belt, but once you spin the crank they no longer line up (well, not for several score revolutions).

You DON'T need to mess with removing plugs or a compression gauge. You'd only ever want to do that if you can't see the cam sprocket, so you couldn't tell whether the mark is pointing up or down at crank TDC. Not the case here. (And it doesn't even matter; as long as the belt is installed with both cam sprockets pointing EITHER up or down at TDC, the installation is correct. It's just hard to tell if the cam sprocket is in the exact right place pointing down, as there is no match mark.)

The only reason people (correctly) care about this is to manage the slack in the belt. Installed correctly, there is no slack on the driver's side, and the slack on the passenger side is all taken up with the tensioner. Just turn the crank twice (to make sure the belt settles into the cogs) and confirm that at TDC both cam sprockets are pointing straight up (or straight down is okay too).

And for most of us, this is a one person job.

cbr600rx7

Thanks.

Yes with the crank and oil pump marks lined up both cams are still pointing to the 12 O-clock position and line up with the marks. The only thing that worries me was that the marks on the timing belt didn't like back up with the cams after turning it over a few times. I couldn't find any where that said specifically if they should line up or not so assumed it was correct but wanted to verify. Also the fact that all three of he marks on the cams and crank had moved exactly one tooth made me feel better.

I will say my belt is crazy tight going from the drivers side cam gear to the crank. It took a lot of effort to get it on and keep every thing lined up.

ADVYOTA

Scope103,

I believe you are interpreting my "No" as a response to you. Its not, it is a response the OP's Question: This is is when I noticed the timing marks didn't line up with the timing cover or the little dot on the crank. All three are one tooth off is this normal?

The belt is new, markings on it are not important vs. getting the motor aligned properly. Crank is aligned when, #1 Piston is in compression. Cam markings would be aligned at the same time with their indexing marks

An extra set of eyes is always a good idea. NOBODY wants to change the belt more than 1 time. For the new and initiated it is a good idea to get help its not a bad thing to do that. I can't tell if you are bragging?

Working on cars with buddies, Dad's, brothers is one of the oldest past times. Shoot Miller High Life has branding to that effect....

To the OP: Take the advice given and use only what you find works for you. There is more than 1 method that works. Good luck man!!

scope103

Okay, this is where getting some insight (from YotaTech) does help. The 3VZE is a non-interference engine, which means that you can turn the cam all you want at TDC with no risk of the valves hitting the piston. So to install a timing belt, just set the crank at TDC (because you got to start somewhere), and don't worry about turning the cam "back" to get the belt on. As long as the cam(s) are in the right place once you pull out the slack, you've got the belt in the right tooth. And since it's a toothed belt, you are either in the right place or off by a whole tooth; nothing in-between.

Now that sounds easy, but how do you know you have "all" the slack out? That's why you spin the crank twice after you have the tensioner installed.

ADVYOTA is mostly right about an extra set of eyes. What I've described above is not some Toyota trick, it's mostly logic and common sense, and having someone to talk to could help. But unlike some other jobs on your truck, the actual work of changing a timing belt only has enough room for one person. Rather than have my wife or kid sitting around just watching me, I like to save them for when I really need a second set of hands. Like brake bleeding (easier if someone else pushes the pedal) or testing the COR (someone turns they key while the other is measuring voltages at the diagnostic port). It never hurts to ASK if they'd be willing to help; I just make sure their contribution is used.

coopster

Scope says " Now that sounds easy, but how do you know you have "all" the slack out? That's why you spin the crank twice after you have the tensioner installed."

You all got me to thinking; (I'm probably 2 or 3 weeks away from putting my belt on)
All the slack does pertain to the tension between the crank sprocket and the two timing sprockets, correct? The tensioner does 'remove slack' from the "up direction" or passenger side, right? After all the crank PULLS the belt around the cam sprockets, right? (One doesn't push a rope successfully). So that correct tension applies to the crank, then the driver then pullin the passenger/odd bank. ?
So what you're tellin cbr is each rotation should make sprocket indexes back to 'correct', as there is slack by definition in belt (taken up by the tensioner) any marks on that belt will nearly have to or could 'move around' some. Or am I spazzin out again.

As a side Q, I was looking at my cam sprockets and got confused. Each sprocket actually looks the same, right? And the lip faces away from shaft on one and towards the shaft on the other. IIRC the pass/odd shaft has the lip towards radiator and the driver/even cylinder side faces the block? At least that's why my ancient hieroglyphics indicate.

Sorry to hijack your thread cbr.

Andy A

LH (drivers side) pulley is flange out towards radiator.
RH (passenger side) is flange in towards motor.

scope103

Correct. http://web.archive.org/web/201003261...67timingbe.pdf

Note that the two sprockets are identical, just installed in opposite directions. On mine, at some point the "knock pins" (which allow the sprocket to drive the cam) had pushed so hard into the sprocket that the pins bent and left divots in each sprocket. I replaced the pins and reversed the sprockets, so the new pins now connect to un-dented sprocket.

cbr600rx7

It seems overly complicated but is actually simple.

What I have found is installing the belt on the drivers side cam first and then to crank and then onto the passenger side cam seems to work best.

cbr600rx7

coopster

Hey cbr,
so that second from bottom pic (a bit blurry) looks like a detent mark, and I guess a line on the belt? (referencing the explanations above re: tension) And thus tight belt back to driver side which is aligned, and then tight on 'back' to the passernger side, aligned? And a few revo's of the crank to make cams circle at least one x, and that's (the cams) all still aligned (save maybe the first mark on the belt at crank sprocket?)

thanks. Sorry to be a pain. At least this will be on record so I can find it in a few weeks!!
And progress is looking good.

Andy A

Looks good, is that after a couple of spins????

cbr600rx7

Any one know what the fuel rail torque specs are for the four nuts that hold them down. Having trouble digging it up.

I did rotate it to make sure the marks still lined up after rotating. However with my belt for every rotation the belt lined move one tooth. Not a big deal as long as they all move the same amount and your crank and cam marks still line up.

Setting the timing belt is not brain surgery and here are some hints.

#1 Don't over think it!!!

#2 verify that the number 1 cylinder is at top dead center. Remeber the crank rotates two turns for every turn of the cam. If you only use the crank and oil pump marks to set it you will be dead on or 180 degrees off and have 0 compression.

#3 You can turn the crank or cams to give you a little slack by about half a tooth. This helps with slipping the belt over the teeth. After turn it back to make sure your marks all line up. I would recomend having the tensioner as soon as you have it all lined up so every thing stays in place.

#4 rotate the crank a few times and line up your crank and oil pump marks. If your cams still line up to the timing cover marks at the 12 O-clock position you have done it

mholme

9ft lbs

Andy A

As long as your marks on the cam sprockets and crank line up after spinning a few times you are good to go. Where the marks on the belt are become irrelevant at that point.

cbr600rx7

Exactly. And that's why I say don't over think it.

siarl

I'm replacing the timing belt and purchased a belt from autozone. A Duralast Dayco belt. The right and left camshaft marks line up with the old belt but the crankshaft marks do not line up with the crankshaft marks on the old one. Which means if I used this belt I can line it up with the camshaft but not the crankshaft or vice versa. Should I get a new belt that is OEM or just use one of the two methods, either camshafts or crankshaft marks, to line up the timing belt?

scope103

Are you sure the belt is on in the direction the marks expect? (The belt itself doesn't care about direction.)

Oh, never mind. The marks on the belt are a convenience, nothing more. If you can't get the belt marks to work for you, just make sure that when the tensioner is re-applied you are at TDC (on the crank) and the marks on each cam sprocket are pointing up. Spin the crank two revolutions to assure yourself that the cam sprockets come back to the same place.

Then you are done. That's all there is to it.