Have you seen a harmonic balancer fail like this?

[phil-l]

I discovered a failed harmonic balancer on a friend's '96 Mustang 3.8 V6 auto (no performance mods; bone stock) that seems to be pretty unusual.

Take a look at the pictures here:

http://community.webshots.com/album/552022226RktMDS

Yes, the balancer is broken into two pieces. And look at that keyway: It's more than *twice* as wide as it should be.

I suspect that the balancer cracked some time ago - but was held in place by the crankshaft bolt. As long as everything stayed in place, it still worked OK. But the vibration started abrading the keyway and causing movement along the crack line. The '96 gets its ignition timing from the crank sensor and the star gear on the balancer, so timing quick got out of whack.

Questions:

- Any idea what really caused a failure like this? Has anyone seen a similar failure?

- I plan to simply replace the balancer, put it all back together and hope for the best. Are there issues I should be aware of, or other problems I may have missed?

Thanks for any insights.

(Apology to admin/moderator: I also posted this is the "Problem Diagnosis" forum - before realizing how little traffic it gets)

[brokenantimatter]

hmmmm?

Ford has a really bad reputation for building shotty crank and cam related parts and I have seen a similar problem happen 98 Windstar where a bad ignition caused the harmonic balancer to viberate to the point where it the teeth sloshed off and and cracked 2/3rds through. They both use the same engine so I pretty sure the powered metal balancer is found in both....Ford has a really bad habbit of cutting corners.

[silverstangs]

I have seen that before, normally caused by a belt that was too tight. Caused by a belt being too small.

[AltecZX2]

hell ive seen fords that have a harmonic balancer, and internaly balanced and still get crank walk lol

[HiFlow5 0]

Wow, I would contact your local Ford dealer and see what they say. Look at the second picture of the balancer, you can see the center ring has walked a little bit and is not uniform. I had the same problem a few years ago on my balancer, but I caught it early on, replaced it and no problems. Good luck, keep us updated.