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Discussion Starter · #1 · (Edited)
Changing my timing belt today, to find I cannot get everything to line up at TDC. IF both cams line up on their marks the cam is off by one gear. This displays #15 on the the bottom black plastic timing belt cover. I have a haynes manual and I've done this on my 3.0 with no problems. I thought everything was supposed to be lined up exactly at zero?

I'm not going to continue the removal until I can get some answers. I've searched and all have proved to be worthless and the dealership I've called said they cannot relay any info due to liability...ugh. The truck runs fine, but could I be doing the motor some justice by lining up all the marks?

Kinda in a pinch, any help would be greatly apprecaited.

edit* idle currently is around 750rpm.

mods feel free to move, but I thought I'd get more reviews here in this thread.
 

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Strange...it seems that if the timing was off by even one tooth you would have some serious issues. Maybe you've found BTDC and not TDC. You've probably tried it every way possible though and I've never torn into one so... yeah anyway good luck with that. Someone will show up with some real knowledge shortly. Standby.
 

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Discussion Starter · #3 ·
Here are some quick pics. The crank is off by what it looks like 1 tooth when both cams are aligned. I've turned the crank clockwise multipule turns thinking it might marry up to no avail.

so as it sits it shows the crank pully mark at 15...never seen this before, not sure what to do before I should continue. Nothing in the haynes says anything about this, nor do I find any in any searches a same/similar question/solution.




thanks guys...
 

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Im not sure if these engines are set up this way or not... But I have seen some engines set up with a secondary set of timing marks behind the covers( like behind the crank pulley). So even though the timing marks dont line up on the outside, maybe they do on the inside. I hope this makes sense... and like I said i dont really know the set up of these engines and how they are marked. Just a thought or something to check... anyways hope it helps if I am completley wrong just disregard...
 

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Pull the front lower cover off. , There is a DOT on the timing belt-Crank pulley, that lines up at the 12'oclock position with a mark on the oil pump housing...this is ZERO TDC and the cams should be timed at 12o'clock with their marks.

The keyway "groove" in the pulleys might be messed up , making it look like the 15 degree mark on the crank pulley.
 

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Discussion Starter · #6 ·
Like I said, the timing on the crank is not lined up when the 2 cams are. The timing mark on the crank is about 1 tooth (pully teeth not those little teeth on the very backside of the gear) away from hitting the mark on the engine block lining everything up spot on.

Hope someone that actully has experience with these engines can provide some insight..:rolleyes:
 

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You are off by what looks to be one tooth on the crank shaft; the marks on the cans look fine. What has happened here is the last person to install the belt didn't catch the mistake, but since the cams are correct, the computer is adjusting the timing to make up for the 15 degree mistake at the crank. The truck will probably run a little smoother after you correctly install a new belt.
 

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Discussion Starter · #8 ·
awsome thanks jomentum and john, I am looking at the the crank its self and the alignment mark. It is not hitting the point on the motor yet. I was also using the black plastic as reference as well which pointed to 15. When I make the dot/imprent on the crank gear hit the mark on the motor, the pully gear points to zero on the black plastic too. Thats how I knew it was off. So if I put everything back to zero and aligned it all I should be ok?

That would make me a happy camper! :D
 

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Like I said, the timing on the crank is not lined up when the 2 cams are. The timing mark on the crank is about 1 tooth (pully teeth not those little teeth on the very backside of the gear) away from hitting the mark on the engine block lining everything up spot on.

Hope someone that actully has experience with these engines can provide some insight..:rolleyes:
Obviuosly you are one tooth off...and yer engine too :rolleyes:

DUDE......did you see the "dot" on the back of the t-belt crank pulley ??
the dot goes to 12o'clock ???

Please , take a look, there you will see what I mean...
1st line up the dot, then line up the cams...
 

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Discussion Starter · #12 ·
Jomentum, I know the mark, believe me, its been bugging me all day. My question was why it didn't line up. Was it because the engine would run better off 15º advanced? Was it because the last guy who I bought it from eff'd up and was off one tooth...and why did it still run no problems? I had so many questions, and none I could find hard evidence to continue any further since i'd never seen this before.

The comment wasn't aimed at you about these engines...the guys above who threw out suggestions who had no experience with this motor.

The little dot in the pulley has been eye balling me all day...believe me, I under stand the principle of everything lined up, just needed to know why my truck was off. I was taken back by not seeing everything lined up 100%, but it ran fine no problems with plenty of ponies. Thanks for sharing your knowledge :kewl:
 

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Discussion Starter · #13 ·

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I believe that you need to remove the harmonic balancer and the plastic cover that has the numbers on it.Look at the gear that the belt actually rides on and make sure that the notch or dot on the pulley lines up with the dot on the oil pump housing.This is what Jomentun is saying,also make sure that the key on the crank is pointing at 12 o clock.The other problem is the harmonic balancer may have the rubber in between the pulleys twisted,this happens when people use a chain wrench and twist it,when they are older this can happen.If you want pm me your e-mail with the year of the truck and I will send you the t-belt manual from Toyota as an attachment.I worked on yotas since 1986 and have the documents from work.
 

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Discussion Starter · #15 ·
I believe that you need to remove the harmonic balancer and the plastic cover that has the numbers on it.Look at the gear that the belt actually rides on and make sure that the notch or dot on the pulley lines up with the dot on the oil pump housing.This is what Jomentun is saying,also make sure that the key on the crank is pointing at 12 o clock.The other problem is the harmonic balancer may have the rubber in between the pulleys twisted,this happens when people use a chain wrench and twist it,when they are older this can happen.If you want pm me your e-mail with the year of the truck and I will send you the t-belt manual from Toyota as an attachment.I worked on yotas since 1986 and have the documents from work.
I understand the dot on the crank gear. I've also been using the notch on the crank pulley as reference. The key (if your reffering to what the crank gear is held onto the shaft by) is NOT at 12 o-clock (this is just to lock the gear on the shaft...doesn't matter if its at 12 or not), but the dot on the crank gear is not pointing to the dot/arrow on the motor..about one tooth off. Like I said, if anyone has read the post, my truck is not lining EVERYTHING UP on the dots when I initally opened her up...by this I mean the Left and Right cam gears and the bottom crank. I wasn't going to pull the belt off until I could find a reason to why they are not lined up.

The pulley and black cover were removed, in the pic I just put them back on to visually show what I meant by 15 when the cams were at their marks.

...putting the crank dot/cam lines at each mark(12-oclock) is not a problem, I just didn't know if my truck ran better at the point it was at(advanced/retarded). So thanks to John, he was able to give me the correct solution and fill me in as to what my truck was doing to correct being off 1 tooth on the crank.

Everything is going back to zero/lined up(obviously I have to take the belt off to make that happen, moving the crank gear about 1 tooth to make it hit the mark)...worst comes to worst I have to put it back how it was if the motor doesn't run right.

Thanks guys...
 

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NO..It will not run "better" a tooth off..Put it back the way it should be and pay no mind to the way you found it. Since when can you trust someone else's work you have no idea about?? Do it correctly and forget about it. There's .02 for ya'
 

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Discussion Starter · #17 ·
Thats exactly what I needed to hear...thats why I'm pretty relentless to letting anyone other then myself or educated people I know work on my vehicles.

THANKS!
 

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I recently changed my timing belt and had similar problems. The way we solved it was to actually place the crank in the zero position, and then rotate both cams slightly off. The problem we were having were as we put the belt on and put tension on the belt the belt was naturally slipping by one tooth.

So to compensate for that, we purposely placed the belt on to be one tooth off in the direction the belt was slipping. That way when the belt went on and slipped, it was actually slipping back in to proper positioning.

Make sense? The key was to position the crank pulley where it belongs and then work the cams to it's location.
 

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Discussion Starter · #19 ·
Yes, Bear, I read about your post and the gear problems. Glad everything worked out in the end. I had the same problem with my 3.0 upon installation of the new belt, reworking the cam gears slightly to account for the slack before the tensioner was released. Thanks, noted on my 3.4.
 

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OK so I really dont want to sound like I am trying to be a jerk here but...if you are so worried about "WHY" the belt was a tooth off ( you apparently already knew it was not right) you should ask the previous owner or whoever did the timing belt job. Yes the engine will run a tooth off apparently pretty good too. It would probally run two or three teeth off, but needless to say the "running" ability would worsen the farther off the timing is.
Boils down to the fact the PO didnt pay close enough attention when installing the belt, or he couldnt get it to line up... but he ran it anyways, and due to the fact these engines have ecus and sensors smart enough to detect detonation it can compensate for running 15 degrees advanced. Now trying doing that in and old school v8 without running a high octane fuel you would hear the nasty knock or pinging associated with running advanced timing..
Im trying to explain this because you asked if the 15 degrees advanced was normal. When others explained that it was wrong you seemed to get defensive and act like we didnt know what we are talking about. NO I havent had experiance with a 3.4 but Ive put timing belts on several other vehicles. I have read thru my service manual so that when I put a timing belt on my truck I know how.
once again not trying to be a jerk just trying to explain a little. Hopefully you were able to get your truck back together properly and all is it well.
 
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