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How To Tighten Crank Bolt?

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DontStartModdin

15+ Year Contributor
72
0
Nov 13, 2007
Milwaukee, Wisconsin
I just replaced the ofh on my '92 GSX with the '90 style ofh. Everything went fine but
as I was tightening the 4 crank pulley bolts the crank bolt came loose on me. My
question is how do I stop the crank from turning so I can tighten the crank bolt?
 
put it in gear... and if it still moves have someone hold the brakes...

When we did mine we used an impact...
 
So you were using the crankbolt as leverage against the pulley bolts, huh? Use this method instead. Assuming the engine is in the car put the car in park then set the e-brake firmly, install the A/C and alternator belts (on the firm end of the scale), and torque the crank bolt to spec. Has an impact been used a hundred times? yes. Is it the best method to use? No. Take your work to the next level and torque critical engine fastners whenever possible.
 
Is there any other way besides using an impact?

Yes, holding the flexplate/flywheel still. Take the starter out. Hold the flexplate in you automatic still using the the teeth that were exposed where you removed the starter. You hold it still using something to jam the teeth, preferably a big flat head. You then take the slack out by rotating the engine while tightening the bolt. Then you hold on really tight making sure your not chipping or messing with any of the teeth on the flexplate, while torquing the bolt down. This is the professional way of doing it. On newer cars, you'll find that they have a panel that you take off to expose the flexplate teeth, but the opening is usually at the bottom of the transmission for easy access with a lift. Every car has a starter, so this is the universal panel.
 
how do I tighten this with A) motor out of car B) no impact gun C) no flywheel ect to hold on to.?
 
how do I tighten this with A) motor out of car B) no impact gun C) no flywheel ect to hold on to.?

Make your life easy and buy an impact man..

I had tons of sockets laying around so I picked up an impact for 50 bucks, an 1/2 adapter for 8 and had myself a tool I use everyday!
 
The torque of the crank sprocket bolt should be about 85lbs and the torque on the 4 little bolts should be 18lbs. Please explain to me how people are breaking the crank sprocket bolt loose... Please dont use a impact for 18 foot pounds. If you are talking about the main crank bolt I have broken them loose with the starter befor. But yeah you need a impact if its out of the car.
 
I have an inner from an old harmonic balancer pulley. Bolt that inner on the sprocket and I use a chain wrench to wrap around that inner. Then with the torque wrench, i play "tug of war" with the torque wrench and chain wrench to meet torque specs on the main sprocket bolt.
 
With the engine on the stand if the oil pan is still off, I put my large Snap-on pry bar between the block and one of the crank counterweights. This holds the crank still for tightening the crank pulley main bolt to torque.

Impact to take off, but not to put on.

I use the same method for flywheel bolts.
 
Last edited:
Since the engine is out of the car and you don't have a flywheel, you can still put the flywheel bolts into the end of the crankshaft (you don't need all 6 or 7, just 2) and use a breaker bar against those bolts to hold the crankshaft still. This usually requires a buddy to hold the breaker bar still which in turn will hold the crank still while you use a torque wrench and tighten it down to the correct amount. This way has a small chance of damaging the threads on the flywheel bolts you are using so be sure to inspect those threads and either buy 2 new bolts for this reason or use a tap and die set to redo the threads. Hope this helps and good luck!
 
Are you trying to tighten the 4 crank pulley bolts or the crank sprocket bolt? Your initial post was about the 4 pulley bolts.

Do not use an impact on the 4 small bolts for the pulley. They should go in easy. If they do not go in easy you have a problem.

As for the crank sprocket bolt use an impact. Preferably an adjustable one you can turn the torque down on. That is what I use. Do not go crazy on it though. Torque specs for it should be about 87 ft/lbs.
 
I've had luck putting it in 5th and then having a friend hold the brakes while I used a torque wrench.

With out anyone pressing on the brakes, with it just being in 5th you should be able to get it torqued down to at least 70 foot pounds no problem. Around 75 in my experience is when it starts to turn, that last five is when I typically need someone to hold the brakes.

*edit* Maybe it was 87 and not 80. I just remember after 75 pounds the crank wants to spin with out someone on the brakes.
 
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