Crank bolt/pulley came loose..need some help

suprafanatic

suprafanatic

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So today i was driving down the interstate, coming up to the off ramp. As i got onto the ramp i down shifted to slow down like usual and i hear a clanking/grinding noise from the engine so i pulled off the road and popped the hood, looking around the front of the motor where the noise came from i find that the crank pulley was loose and wobbling.

The crank bolt some how got loose and backed out some. So i got a socket and started tightening it back up. I tightened it as much as i could by hand but the pulley was still a little loose and wobbly. To get it tighter i needed a way to keep the cam gears from turning but i couldn't.

So i called a tow truck and had it towed to a local shop. The shop was closed at the time so i wont find anything out till later tomorrow... or later today i guess i should say. So i guess I'm wondering how could this have happened?? And more importantly what are the chances of any internal parts being messed up from the pulley coming loose? Other than the griding sound of the pulley the car idled and revved smoothly, didn't sound like it had any internal damage, but i don't really know..

Anyone else every have this happen? any ideas, thoughts, or advice is appreciated!!

thanks
 
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NewWestSupras

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Mar 1, 2006
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The biggest question is whether the keyway is damaged. If it is fubared, people have fixed it by welding another keyway on the other side of the crank, and putting the balancer at 180 deg. The alternatives aren't pretty. Hopefully it just wasn't torqued enough before and it's all good.. gl.
 
gaboonviper85

gaboonviper85

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They are the two slots cut into the snout of the crank...half moon keys go into these slots and then you slide the timing gear and crank pulley over them....these keys stop the pulleys from shifting but if you don't keep the bolt tight then the pulley will snap the key...

Your internals are probably ok if you caught it intime but odds are the crank is shot and will need welded up and remachine'd.
 
gaboonviper85

gaboonviper85

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The pulley is a light press fit...takes some ass to get one off. Not to mention it now has a broken key wedgeing it tight.

If the pulley came loose you can bet the key is fubar.
 
gaboonviper85

gaboonviper85

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Well to weld and re grind the snout and key then straighten you're probably in the $350 range....new crank you may need new bearings all around plus the crank polishing to give you the proper oil clearance in the $250-300...

That's just a ruff guess from ruff average prices.
 
CyFi6

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i wouldn't scare him too bad just yet. Just wait and find out what your mechanic says. A balancer for $400 is ridiculous you can buy one used for much cheaper than that...
 
gaboonviper85

gaboonviper85

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CyFi6;1246813 said:
i wouldn't scare him too bad just yet. Just wait and find out what your mechanic says. A balancer for $400 is ridiculous you can buy one used for much cheaper than that...
Click to expand...

Buying a used one isn't a good idea as they are old and dry rotten or even oil rotten!

I'm not trying to scare the guy hell no...but I'm not going to lie and say this isn't a big deal. Obviously dude already has big money in his car as I've been keeping up with the things he has done...no sense in cheaping out now.

Damage is done...that is for sure...and cranks aren't plug and play so if he gets another crank it's gonna have to be worked either way which is gonna cost some bills.

Not trying to be an ass...just being realistic as possible with the situation as described....sorry
 
shaeff

shaeff

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Start at post #330:
http://www.supramania.com/forums/showthread.php?t=29149&highlight=keyway&page=7

I do NOT recommend fixing the problem the way I did, but it worked until he blew the motor. (not due to the crank pully problem, either)

Any damage will be external, as 7M's are non-interference motors, unless you've milled the head/block a LOT and didn't compensate with proper headgasket size.

For reference, the crank pully should be torqued to 195ft. lbs.
 
suprafanatic

suprafanatic

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shaeff;1246934 said:
Start at post #330:
http://www.supramania.com/forums/showthread.php?t=29149&highlight=keyway&page=7

I do NOT recommend fixing the problem the way I did, but it worked until he blew the motor. (not due to the crank pully problem, either)

Any damage will be external, as 7M's are non-interference motors, unless you've milled the head/block a LOT and didn't compensate with proper headgasket size.

For reference, the crank pully should be torqued to 195ft. lbs.
Click to expand...

You apoxied the key back on the crank???? I cant believe that would hold for even a second if it just snapped through metal. thats not the way i would go..lol.. so the shop called and they said I need a new balancer, new crank bolt, and the keyways were messed up. They said there could be more damage to the crank but they wont know till they get in there and see... so far a quote for those new parts and labor is $967.. parts wont be in till tuesday from toyota.
 
gaboonviper85

gaboonviper85

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Should have got the ati damper...it's a bit cheaper and has more cool factor LOL

Best of luck to you but the prices I gave you were if you did the work yourself...obviously it's now gonna cost you much more.
 
suprafanatic

suprafanatic

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ya i know.. just in a situation where i cant do the work. and need it done fairly quickly... im just hoping there isn't any serious internal damage beyond the crank :( such a stupid issue causing such a bad problem.. ugh
 
MarkIII4Me

MarkIII4Me

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Apr 10, 2005
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I had the exact same thing happen to me on engine #2. Unfortunetly, the pulley bolt was completely fubar and would eventually get loose when I tried to keep tightening it on the crank. I tightened it as best I could and kept driving. Roughly 30 minutes later the bolt flew out and I destroyed my bottom end. When we pulled the engine and pulley, you could grab the crank and shake it up and down like 3 inches. It wasn't pretty. Needless to say that's when I went ahead and purchased engine #3.

Best of luck to you man.
 
suprafanatic

suprafanatic

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well ya i knew if that bolt came all the way out it would fack up the motor so i just had it towed and didn't drive it any further.... but damage has still been done i guess..
 
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