Low Speed Timing Belt Break... Need advice

You think the fan clutch bearing bracket is necessary?

 

Back to earlier chatter, you can get those stickers for $1-2. Seeing one is confidence inspiring, but you should still verify to make sure the seller didn't pay $1-2 for a sticker to avoid paying $1k-2k to actually get the job done.

 

Shifty.... you've been hurt before haven't you

 

Lets just say "I've seen some shit". Not on my truck yet, although I did find some interesting stuff, but ...

It looks like OP may be in a similar situation, but the PO didn't even bother to buy the sticker

 

2 dollars saved is a soda pop.

Or I havent checked prices recently, can you still get coke for 2 bucks?

 

Even if my frame is rusted to shit... I'm still gonna give the buyer a heads up. Some things can kill people. I've been lucky I guess. I like craigslist and facebook and haven't gotten too burned. Well, there was the first time I bought a laptop haha! Never buy a laptop on Craigslist.

 

I probably won't have the time to get back into this until Wednesday. But I am still not entirely sure what the process is to align the cams on an engine where the belt has broken. In this first pic I posted of the right cam I can see the alignment mark is vaguely in the ballpark but on the left cam I don't see any marks? Seems like the left cam is way out of wack? Do I just rotate the each cam until they are in aligned with the marks and then set the crank at TDC? Then proceed with putting on the belt?

 

I haven't had to do this myself on VVTi engine. I see @Bilgepump has been away for almost a year now, but he'd be someone I'd tap to give pointers. Likewise @EvilMilkshake may have input.

 

Only if you can buy those 10 oz aluminum cans.

 

Had this saved from when I was gathering info years back when I was planning to do mine. Wished I had saved thread but it was either from TT or TS before I stumbled on to Tundras….proceed with caution, no bent valves. Also as someone mentioned earlier, wrench not ratchet !

***"The white mark on the crank dampener indicates "top dead center" for the number 1 cylinder only.

The camshafts position, relative to crankshaft position, determines whether or not the pistons are on their intake, compression, power, or exhaust strokes.

Since each piston reaches it's own TDC once per crankshaft revolution, 1 piston out of 8 is at TDC for every 45 degrees of crankshaft rotation.

If you need to realign the camshafts to the crank..... be aware that the toyota V8 is an interference engine. Valve damage will occur if you rotate the crank without using caution.

The following is the safest way to realign the timing belt without risking major damage to the engine.

1. remove the spark plugs, this step will allow you to turn the engine by hand and let you feel for any piston to valve contact.
2. Gently turn the crank to 22.5 degrees BTDC ( before top dead center ) or ATDC (after top dead center). This position will assure that none of the 8 pistons is at TDC, which reduces the chances of piston to valve contact.
3.Realign the camshaft pullies to the respective timing marks.
4. Rotate the crankshaft back to TDC.
5. Install the timing belt on the engine.
6. Rotate the engine by hand a few times and double check the belt alignment.
7. Reinstall the spark plugs.
Provided that you put everything else back together correctly during the reinstall phase, your engine should run fine."***

 

The writing on mine has faded off. I could easily overwite it and replace the 1 with a 2.

 

Thanks man this is definitely helpful.

 

I found it recommended in another thread as a wear item so I just replaced it as my truck has 185k on it. I figured I had to take it off anyways and after being quoted by the stealership over $5k to do the job, adding another $100 to my parts order wasn't bad. But to each their own.

 

I feel like it's a hard choice to make here overall unless your budget is very large. Do you just replace the belt and nothing else in case it doesn't work anyway? I'd be inclined to think that would be best instead of putting all those good parts on an engine that might be bad. Just slap a new belt on and rotate it with a breaker bar and see how it feels. Borescope camera down the spark plug holes would tell you a lot too.

 

I’m thinking you should think about pulling the cams, spinning the crank to TDC and then reinstalling the cams. I know the VVT system makes this more difficult, but getting the engine synched back up is going to be tricky.

 

I wonder if the previous owner was confusing the serp belt with the timing belt. I bet this happens a lot when people are not knowledgeable about engines.

 

The Toyota OE timing belt has paint marks on it and the manual will explain how to do it. Easy.

 

Lesson to be learned. If in doubt change it out. If PO tells you it was recently done, trust but verify by pulling a cam cover and visually inspect the belt. If it looks old, it is.

 

Another possibility is that the previous owner did replace the belt but used a cheap aftermarket belt. We've seen those break too. If he was telling the truth, it had 80k miles on it which would be a lot for a cheap belt.

@violinriver does the broken belt have any identifying marks on it? We need to know, for science.

 

I'm still waiting to remove most of the broken belt behind the lower cover. Everything exposed doesn't have any markings. Waiting for the crank tool to arrive on Tuesday and won't have time to get back into the truck until Wednesday. I will definitely update on Wednesday.

 

This video is an interesting watch. This guy tears down a 4.7 VVTi engine he received with a broken timing belt expecting to find major damage and finds… none. Fingers crossed.

https://youtu.be/99hQ8AowTig?si=SeyAo9HQLTZ8mwzB

 

Fingers crossed for you OP!
I just did my timing belt job this weekend,

$183 aisin tkt-021 engine timing belt kit with water pump - compatible with select lexus GS400, GS430, GX470, LS400, LS430, LX470, SC400, SC430 toyota 4runner, land cruiser, sequoia, tundra

aisin tkt-021 kit with some long life Toyota coolant.
Easy peasy job with basic tools. Started Saturday morning, finished at 8/9pm. Take it slow, take note of the routing for the sensors and label everything.

 

Get the new pulleys all in this post

 

Had some time to throw a few hours at it today. After some fuss was able to remove the crank bolt and lower timing cover. The belt was shredded and bundled up around the crank pulley- pretty nasty stuff. Was able to get the new idler pulleys installed along with the new water pump. All of the bearings seemed in good shape still and seemed original. Getting the old water pump paper gasket off the mating surface was a pain in the ass but I made sure to do a thorough job. I pulled the spark plugs and put my new Amazon endoscope to use. To be honest for $32 it is an amazing tool and piece of technology. Nothing looked out of place in any of the cylinders and I did not detect any evidence of damage. I'm trying to reign in my optimism but so far so good. Tomorrow I will try to get things aligned, put the belt on, and hand turn the crank a few times. If all goes well I should be able to put everything back together and give her a whirl.

 

Thank you gang and remember, we're pulling for ya! (Pun)

No tundra should feel the pain of a broken heart engine.

 

Ugh got up early today to throw the belt on before starting work. Got everything lined up, things are going great, and then I turn the engine over about 1/4 way when I feel some binding. Scoped the cylinders again and I have a broken valve in #8. Time to pivot. What a bummer.

 

Damn. That sucks so bad. I was hoping for a better outcome.

 

Yeah totally blows. Felt like I was 95% in the clear and then slapped down. Guess I will be looking into an engine swap probably. There are a couple of parts trucks for sale locally with good motors.

 

On a positive note, it's a lot easier to work on the new engine before you install it. You could thrown some headers on it pretty easily. Do all the necessary maintenance while it's on an engine hoist and you'll be good to go another 100k miles.

 

I am not much of a mechanic, if at all really. But can't the valve be replaced? Does a broken valve warrant an engine replacement? Sorry and thank you for education.