One cam moved during timing belt job

[White98SR5]

I'm doing the timing belt /water pump job on my 98 SR5 3.4, and I need to ask a question before I move on. So its time to install the new belt, and for some dumb reason I grabbed the passenger side cam sprocket and tried to turn it clockwise just a wee bit. It jumped over to about 3o'clock. So, I went ahead and turned it clockwise until the marks lined up again. So here is my question....am I good to continue? Will making that one revolution on just one cam put it back where it needs to be or am I 180 degrees out on that one now? Thanks for any feedback; this is my first time tackling this job.

 

[LittleCaesar]

Good to go. Keep working on it. Post up when you are finished.

 

[Tyler James Inc]

As long as you line all the marks up, you'll be good to go [emoji1598]

 

[White98SR5]

Awesome, thanks guys. I will carry on and post when its done! :zoom:

 

[aontkos]

I had this problem with the passenger side cam. It shifted to the 3 o'clock position three or four times when I was attempting to get the belt on. I was worried because I hadn't heard about this happening to anyone else. I've put 2000 miles on it since the belt change and I've had no problems so far.

 

[Tyler James Inc]

I had this problem...I hadn't heard about this happening to anyone else.

That's because it isn't a problem at all. It simply moves the valves up/down. As long as you line the marks on the belt up with the corresponding cam/crank marks, you're good [emoji1360]

 

[sambishop]

If we had an interference engine, a lot of people would have bent valves from the sprocket jumping over on us. Happened to me a couple times when I did the job.

 

[alumarine]

A mechanic told me to loosen or remove the spark plugs on the passenger side.

This helps prevent the tendency for the sprocket to want to snap over because one of the pistons is near the compression stroke.

 

[19963.4lsr5]

Doing mine the difficult cam was the drivers side. Everything on the dots I started at the crank then up to drivers cam and it was like 1/4 tooth off. I finally got tweeking the cam and crank position slightly. Everything else laid in the sprockets nice and easy. I wanted to make sure the belt teeth were I there proper spot on the non tensioner side so tension wouldn't roll the cams as the belt tensioned up.


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[phattyduck]

Spring clamps or small c-clamps are your friend when getting the belt lined up on a multi-cam engine... get the crank aligned, clamp. get one cam aligned, clamp. etc. Doesn't need to be tight, just enough to keep the belt from slipping.

-Charlie

 

[raulb21]

sorry for re-opening discussion on an old post but I'm experiencing a similar issue. I'm doing the timing belt/water pump on my 99 4Runner and all was going well, I had everything set to TDC and I was installing the new timing belt when suddenly one Camshaft moved. I read several posts and came to the conclusion i could rotate clockwise back go TDC. So i did so, put the crankshaft back on and rotated 2 revolutions to test the timing and now the crankshaft is off when the cams are at TDC. What happened? What can I do in this situation? This is my first time tackling this job and I've been very careful and tedious but as Im finding out, things happen. So thanks in advance I've came here to read many posts before but I finally joined. Thanks for any help!!!:yield:

 

[4Reak Show]

First off, 3.4's are non interference engines meaning major engine damage will NOT result from being out of time. So don't be shy to rotate as many times as needed to gain the results to satisfy you.

That being said, what part is off? I ask because when I did t-belts a lot I marked the belt itself as well as sprockets and engine. After test rotating, the marks on the belt will NOT line back up exactly. So instead confirm the marks on the sprockets align with the engine after install.

Make sure the tensioner pin is pull. That pin being installed allows for slack and slop and will skew results.

Finally, the marks are rarely exact. And by exact, I mean EXACT EXACT. I've seen it almost every time over the years and after setting up you look and go "man those 2 marks are dialed but the third mark is like 1/16 tooth off" and that is normal.

Post up pictures if you're worried and we'll help to confirm you're accurate or off. IIRC the cam marks are the lines on the back cover NOT the "T" looking mark. And the crank sprocket has a dimple on the oil pump housing NOT the dimple on the face which aligns with a mark on a new belt.

Any more questions ill help out as best I can. I've done a few timing belts, mostly Toyotas.

 

[kevinRR]

I'm doing the timing belt /water pump job on my 98 SR5 3.4, and I need to ask a question before I move on. So its time to install the new belt, and for some dumb reason I grabbed the passenger side cam sprocket and tried to turn it clockwise just a wee bit. It jumped over to about 3o'clock. So, I went ahead and turned it clockwise until the marks lined up again. So here is my question....am I good to continue? Will making that one revolution on just one cam put it back where it needs to be or am I 180 degrees out on that one now? Thanks for any feedback; this is my first time tackling this job.

Have someone give you a hand and it would be easier. Loop the belt around the components have a buddy use an open end wrench to line up both cam gears and you can slip the belt on. You can use paper binding clips to hold the belt on to the cam gear.

 

[kevinRR]

sorry for re-opening discussion on an old post but I'm experiencing a similar issue. I'm doing the timing belt/water pump on my 99 4Runner and all was going well, I had everything set to TDC and I was installing the new timing belt when suddenly one Camshaft moved. I read several posts and came to the conclusion i could rotate clockwise back go TDC. So i did so, put the crankshaft back on and rotated 2 revolutions to test the timing and now the crankshaft is off when the cams are at TDC. What happened? What can I do in this situation? This is my first time tackling this job and I've been very careful and tedious but as Im finding out, things happen. So thanks in advance I've came here to read many posts before but I finally joined. Thanks for any help!!!:yield:

Your going to have to turn it more then 2 rev for all the timing mark to align all together.

 

[raulb21]

First off, 3.4's are non interference engines meaning major engine damage will NOT result from being out of time. So don't be shy to rotate as many times as needed to gain the results to satisfy you.

That being said, what part is off? I ask because when I did t-belts a lot I marked the belt itself as well as sprockets and engine. After test rotating, the marks on the belt will NOT line back up exactly. So instead confirm the marks on the sprockets align with the engine after install.

Make sure the tensioner pin is pull. That pin being installed allows for slack and slop and will skew results.

Finally, the marks are rarely exact. And by exact, I mean EXACT EXACT. I've seen it almost every time over the years and after setting up you look and go "man those 2 marks are dialed but the third mark is like 1/16 tooth off" and that is normal.

Post up pictures if you're worried and we'll help to confirm you're accurate or off. IIRC the cam marks are the lines on the back cover NOT the "T" looking mark. And the crank sprocket has a dimple on the oil pump housing NOT the dimple on the face which aligns with a mark on a new belt.

Any more questions ill help out as best I can. I've done a few timing belts, mostly Toyotas.

So this is where it's at, I tried to take pictures to best explain whats going on. So when the crankshaft is at 0 the two cams are both together at being about a tooth off from TDC. Do I need to pull it off and re-align everything? It only appeared off time after installing the new belt. I'm guessing the pressure possibly moved something, I'm not too sure.... ahhh

 

[4Reak Show]

Yeah you're definately off a tooth. It's more accurate if you can pull the crank pulley and cover and get eyes on the sprocket itself. It has a mark on the engine and sprocket. From there, you can LOOSEN and not fully remove the tensioner bolts to relieve some pressure, clamp the belt on the cams with binder clips or close pins, pull the belt off the crank, rotate the crank the appropriate direction and install belt one tooth over.

What tends to happen is you put the belt on and slip it right onto the sprockets. Well, there is slack on the driver side of the belt system (since it rotates clockwise) and when you spin the crank by hand at first, the slack gets removed and placed onto the tensioner side (passenger side) of the belt system. Hence, making you one tooth off.

When installing, you want it to be difficult to get the driver side portion of the belt on the sprockets and have all the slack on the tensioner side. Does that make sense?

At any rate, you are indeed off time by what looks like a complete tooth.

 

[4Runner4Leon]

If everything lines up as shown below, you should be good:



Yours does seem to be about a tooth off, but it's hard to tell without looking straight onto the pulleys.