SethGbird

Hey I am having an issue my mechanic said he torqued the harmonic balancer bolt to spec after putting on a new timing chain. I have had the car back a week and went to start it there was a thudding sound. Turned it off and saw the belt was coming off looked under the car and the balancer bolt wasn’t even figured tight. It had shared the woodruff key off at some point too
any ideas how to the woodruff out, I am worried I am going to have to take off the front end. And does anyone have an idea on why the bolt came loose? Is this a “common” problem?

Sheared off woodruff key

Harmonic balance

ILM-NC G37S

iTrader: (3)

First, the crank bolt coming loose is not a common issue on these or any other cars I have ever wrenched on. I can envision three possibilities:
- reused crank bolt (big "no no");
- improper bolt torquing (these cars: 33ft-lb.+90˚);
- binding load on the pulley's causing shock/ stress.

As for the woodruff key shearing, more than likely the key was either not fully seated into the groove or was installed improperly on the crank nose allowing the key to "creep" as the crank pulley was being installed. Again, this can be attributed to reusing old parts. Unless there was something external causing excessive shock to the key the failure rate for those is relatively low.

In the old days a blow torch and a small screwdriver would pop out a sheared key. However, with this engine, I do not think you will be able to get the sheared key out without removing the cover and the crank sprocket. Any tricks will risk debris falling into the engine/ timing assembly/ oil pump, etc. I'll tag @BULL here as he has vast experience with this engine and may have some ideas.

Either way, I'd push the issue with the mechanic. He did the work and should make it right.

SethGbird

Thank you for the information! It sounds fishy pretty important part to be having a “common” issue with. As far as reused parts that is good to know the bolt defiantly looks older than a week. My guess is then the bolt had been loose the whole time a rattled the key till it finally broke. When looked to check the bolt is was about half way threaded, pulley falling off. Definitely taking this up with the mechanic, unbelievable. He had suggested I do the timing chain and this what I get back 🤦‍♂️

ILM-NC G37S

iTrader: (3)

That most definitely is a improper installation.

What were your original symptoms that warranted replacing the timing chain(s)?

SethGbird

Beyond regular maintenance nothing warranted it. It’s just shy of 200k

ILM-NC G37S

iTrader: (3)

Classic example of "If it ain't broke, don't fix it!" Sorry that the mechanic screwed it up. Hopefully he will do right by you.

Good luck, Seth. Please keep us updated.

SethGbird

Ya absolutely won’t be doing that again lol

Yes definitely will keep ya posted thank you for knowledge. He better fix it or he’s going to pay for it, no excuses for this in my book.