Crank Pulley Bolt flew off !

slow_yota

Gotta Pay To Play
For some reason or another, My crank pulley bolt got loose and came off.
I started up the supra yesterday and pulled out of my garage...Went back to close the overhead door and theres my crank pulley bolt.

So....How do I lock up the engine so I can torque this guy back down?

Its a 5 spd if that matters...And the crank pulley is solid, No holes in it at all.
 
Oct 11, 2005
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Thousand Oaks, CA
Block the wheels, e-brake on, put it in 5th gear, and torque the nut to 195 ft-lbs. The reason it fell off was because it was not torqued properly the last time it was removed. I would check for damage to the crank snout, pulley, and key before reassembling.
 

Dan_Gyoba

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Aug 9, 2007
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Or, so long as your clutch will hold 200 ft-lbs of torque (IE, your clutch isn't toast), just put it in 5th, set the e-brake and you should be able to apply 195 ft-lbs of torque to the crank bolt just fine.
 

Backlash2032

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Sep 20, 2010
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Put it in 1st! 5th is way easier to move than 1st.

Next time you're on a steep hill, pull over and put the car in 5th (engine off obviously) and see if it will roll. I bet it will. Then try 1st and i bet it will hold the car.
 

Wayne G.

87Turbo 5sp Targa
Apr 19, 2005
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Actually you got it backwards - try putting the car in first with the engine "running" and start on a hill that will work , then put it in 5th and see what happens. He is going to be
putting 195 ft. lbs of torque on the crank as the running engine would. So much easier to hold in 5th than 1st. In 1st gear you might be able to overcome the parking brake.
 
Last edited:

mk3_7m

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Jul 21, 2007
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I reckon 5th gear because the engine has to over-come alot more load to move the car. So for a human to do that.... well.. you'd have to be superman.
Probably the ratio is what makes a big difference.
 

Backlash2032

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Sep 20, 2010
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Im just saying, its easier to turn the motor over with the car in 5th than in 1st. Try doing what I said. With the engine off, 5th gear on a slight hill the car will roll. Turning the engine over. Granted, very slowly, but it will turn the engine

1st gear wont roll, and the engine obviously wont turn.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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Backlash2032;1757641 said:
Im just saying, its easier to turn the motor over with the car in 5th than in 1st. Try doing what I said. With the engine off, 5th gear on a slight hill the car will roll. Turning the engine over. Granted, very slowly, but it will turn the engine

1st gear wont roll, and the engine obviously wont turn.

100% wrong.... :nono:

1st gear and >195 ft/lbs on the bolt and the car will drive forward due to the mechanical advantage from the gearbox reduction, 5th gear is an overdrive therefore no mechanical advantage and you can get the bolt to 195, job done.
 

Dan_Gyoba

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Aug 9, 2007
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You're going at it backwards.

In 1st gear, the wheels have less effect on the engine, the differential gives the wheels a 3.909:1 (Or 3.73:1 or 4.30:1... whatever) advantage on the driveshaft, so there's several times more torque at the driveshaft than there is at the axle. 5th gear gives the driveshaft a mechanical advantage over the crankshaft. First gear gives a large mechanical advantage of the crankshaft over the driveshaft. Since we're applying torque to the crankshaft, that makes the car more likely to move.

5th gear is what you want for this deal.
 

destrux

Active Member
May 19, 2010
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I agree, 5th would be the best gear numerically, but I prefer 4th. There's less "squish" before you reach the torque value. My theory is that you're not flexing the transmission parts as much because you're not really using a "gear" in 4th.
 
Apr 4, 2005
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BlackDevilSupra;1757792 said:
Just want to confirm that this tool will work on the 7M? The description indicates it's for 1990 Lex' and 1996 Toyo's and later. It'll be quite useful especially if your motor is on a stand.

it should let me try it on my 7M later today and i will get back to you
 

Backlash2032

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Sep 20, 2010
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Dan_Gyoba;1757717 said:
You're going at it backwards.

In 1st gear, the wheels have less effect on the engine, the differential gives the wheels a 3.909:1 (Or 3.73:1 or 4.30:1... whatever) advantage on the driveshaft, so there's several times more torque at the driveshaft than there is at the axle. 5th gear gives the driveshaft a mechanical advantage over the crankshaft. First gear gives a large mechanical advantage of the crankshaft over the driveshaft. Since we're applying torque to the crankshaft, that makes the car more likely to move.

5th gear is what you want for this deal.

Now that I think about it, that makes sense. Learn something new everyday.
 

te72

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Mar 26, 2006
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If you don't learn something new in a day, you're probably doing it wrong, or you're dead. Just yesterday, I found a pimple in the strangest place... never would have thought. :p