I'm not sure what a harmonic balancer is for, I suppose to balance the engine. If they go bad, do they just fall off or what?

 

Do a search and you will find lots of answers...this is a hot topic

 

Won't fall off, but move forward and take out the steering rack or back and grind into the oil pan and front timing cover. Or wobble really bad and throw the belts off.

 

It's more of a vibration dampener than a balancer, though some corvettes do have balance weights in them.

 

From what I read in the FSM only manual trans cars have the balance weights in them.

 

One of two things happen when the balancer goes bad. The first is a separation of the top half from the center half of the damper--that is the membrane holding the two pieces together stars separating from the balancer causing sever vibration to the system. This causes the two belts to fly off the PS/alternator/AC system and often tearing up the the hood insulation. The second is the crank bolt becomes loose and the entire balance start to move toward the PS rack or backs into the the timing chain cover. This can also cause the belts to fly off and tear up the hood insulation. The OEM crank bolt is Torque to Yield and most do not have it properly replaced (torque sequence) with a new bolt so many recommend an ARP replacement bolt.

When you have the balancer replaced you should also pin the new one to the crank for added insurance.

 

 

SORTA KINDA Correct.

The main issues with an OEM Dampener is the rubber dampening strip between the center HUB and the outer ring, becomes debonded. That causes the outer ring to spin on the hub . When its no longer bonded it can also walk forward and or Aft and damage the steering rack housing and or the front engine cover.

NOTE! The dampener is held to the crank snout with two methosd. The VERY TIGHT interference fit between the dampener and crank snout and the TTY bolt..

There have been Dampener Torque To Yield (TTY) bolts that have come loose but the rubber debonding is more of an issue.

The procedure for removing/ reinstalling the dampener and properly installing (torqueing) the TTY MUST be followed to the exact procedure in the service manual.

Most people purchase an aftermarket dampener (better quality and wont separate) and install it using the TTY bolt. Some purchase the ARP Dampener bolt which is NOT a TTY and can be reused over and over again. It gets torqued to a specific torque (190 ft/lbs off the top of my head) with excellent results.

Its not a matter of IF the dampener fails but WHEN it will fail. Normally it gives you ample warning as you will see the outer ring wobble slightly and or the rubber strip between the ring and hub start bulging out.

The OEM dampener TTY bolt normally fail to hold the dampener on when:

1. Its installed incorrectly (not per the service manual procedure)
2. The threads inside the crank snout are damaged (due to improper hub removal or installation)
3. Damaged crank snout mating surface. (happens when the bolt fails and the dampener spins on the crank snout.

Pinning the dampener to the crank is NOT a requirement UNLESS you are driving a power adder. HOWEVER, Some people add the pin for piece of mind (as I did) to prevent it from spinning on the crank. In my case it was over kill but I know it pinned!

Bill