Harmonic Balancer

Tech discussions on the L77 6.0L V8.
Post Reply
Papa_Linguine
Posts: 6
Joined: Thu Dec 16, 2021 2:17 pm

Harmonic Balancer

Post by Papa_Linguine »

Hello everyone,

Before I purchased my '12 9C1 back in march the department had the harmonic balancer replaced under warranty on March 10th, 2014 @15,085 miles. 43k miles LATER with the odometer at 61k miles the same problem has appeared. My question is if GM revised the harmonic balancer, if that's the case I don't believe they used the revised part. The number listed on the invoice shows the part number 1263-5649 - (S) Balancer
9225-2340 - (S) Tensioner

The customer states: "EXHAUST RATTLE FROM UNDER VEHICLE SEE STORY D"

"CHECK FOR TICKING NOISE FROM ENGINE AREA, WAS TOLD IT WAS THE HARMONIC BALANCER OUT OF BALANCE... PERFORMED INSPECTION FOUND VEHICLE HAD VIBRATION AND TICKING...REPLACED AC BELT TENSIONER, AND REMOVED HARMONIC BALANCER AND REPLACED WITH NEW HARMONIC BALANCER, INSTALLED ALL PARTS REMOVED AND CHECKED OPERATION OK NOISE AND VIBRATION NO LONGER PRESENT."

Now the same problem has came back, I have a slight belt squeal on start up and a light tapping. Doesn't sound like a lifter almost as if the exhaust manifold has a leak. It's difficult to tell if the harmonic balancer is out of balance just by eye sight plan on taking it in shortly. I'm curious if anyone has had a similar experience with their PPV? I'm gonna do some more digging on Monday when I go back to work to dig through the GM catalog. I believe I read somewhere in a thread that the part was revised and the original 12635649 is no longer available order since it was superseded to 12674582.

All insight is welcomed!
Post Reply