Center bolt on crank pulley broke

acuraguy81 · Jul 15, 2010

I broke the bolt putting the balancer back on the crank. Any idea if I just put the other 3 bolts through the pulley onto the balancer will that be enough to hold it all? Or will I have to easy out the broken stud which will be a pain in my ***.

Alpheus · Jul 15, 2010

Re: Center bolt on crank pulley broke

The 3 other bolts do nothing to hold the balancer to the crankshaft. It must be all the way back on the shaft so as to make a seal for the front oil seal. You are going to have to get that bolt out of there.

45Auto · Jul 15, 2010

Re: Center bolt on crank pulley broke

You're talking about breaking the center bolt that goes into the crankshaft and holds the balancer on?

No options there, you have to have that bolt in there.

Without it, the balancer/pulley will slide off the front of the crank once you start running the engine and go flying around tearing up stuff or hurting people.

At 4000 RPM the outside of a 6" balancer is moving at just over 100 ft/sec. That's over 70 MPH. Imagine the damage that balancer could do running around inside your boat at 70 MPH.

a70eliminator · Jul 15, 2010

Re: Center bolt on crank pulley broke

Did you snap it because it cross threaded? if yes than you'll probably have to have it removed professionally. If you just cranked it too tight and it snaped then you have a good chance of getting out.

haulnazz15 · Jul 15, 2010

Re: Center bolt on crank pulley broke

I don't know how tight he mut've had it since most of them are to torqued to 80-90ft lbs as it is. He must of really been wrenching on it.

Bondo · Jul 15, 2010

Re: Center bolt on crank pulley broke

Ayuh,... My guess he was using it to install the balancer, rather than the Right Tool....

Bt Doctur · Jul 15, 2010

Re: Center bolt on crank pulley broke

Yep,i concur. without the threaded rod(tool) your left with few options.
Beat the balancer on and install the nose bolt
Get a longer bolt of that thread size and use spacers to draw it in.
Start the balancer and try to draw it on and break the bolt
Neither 1 or 3 will make your day. 2 is the logical choice.
But then again, asking how we would do it sounds like a better choice.

acuraguy81 · Jul 15, 2010

Re: Center bolt on crank pulley broke

I was using a install kit i got from Oriellys so i was doing it all right the stub of the install kit is what broke.

zbnutcase · Jul 15, 2010

Re: Center bolt on crank pulley broke

acuraguy81 said:
I was using a install kit i got from Oriellys so i was doing it all right the stub of the install kit is what broke.

And that does happen, have broken 3 or 4 over the years, all on small Chev because its only 7/16, and every one came right out because they weren't bottomed out. And Snap On gave me free replacements!

acuraguy81 · Jul 15, 2010

Re: Center bolt on crank pulley broke

Tell me how you got the it out? What type of easy out did you use?

acuraguy81 · Jul 15, 2010

Re: Center bolt on crank pulley broke

bump. any tips with what easy type to use i have seen 2 types?

Bondo · Jul 15, 2010

Re: Center bolt on crank pulley broke

Ayuh,... I'd start with drilling the offending piece, Through with a lefthanded drill bit...
Usually the torque of the drill is all that's necessary...

For Easy-outs,... I prefer the short plugs with lefthanded spirials cut into 'em...

The Trick with Easy-outs is ya gotta drill clean Through the offending piece....

acuraguy81 · Jul 15, 2010

Re: Center bolt on crank pulley broke

i will try the backwards drill bit first where would be the best place to find a good drill bit like that?

Bondo · Jul 15, 2010

Re: Center bolt on crank pulley broke

I get mine from my Snap-on guy...

acuraguy81 · Jul 15, 2010

Re: Center bolt on crank pulley broke

yea that would be nice. I will try the local tool shop tomorrow when they are open.

acuraguy81 · Jul 15, 2010

Re: Center bolt on crank pulley broke

good luck for once. i though why not try to turn it with a small screw driver or some thing and boom it turned very easy almost like it was on a ball bearing. so need less to say i got it out!!!!!!!!!!!!!

6meter · Jul 16, 2010

Re: Center bolt on crank pulley broke

My installer is about 2lbs with a handle on it. Worked just fine for 15 years in the Chevy garage.

Bondo · Jul 16, 2010

Re: Center bolt on crank pulley broke

6meter said:
My installer is about 2lbs with a handle on it. Worked just fine for 15 years in the Chevy garage.

Ayuh,... But it's 'ell on the main thrust bearing....

JustJason · Jul 16, 2010

Re: Center bolt on crank pulley broke

You need to press it smoothly... not beat the 'ell out of it.

Center bolt on crank pulley broke

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