Corvette C5 and C6 Harmonic Balancer problems raise serious concerns regarding General Motors solution to growing problems with Corvette C7

During the previous generation of Corvette, there were several problems that plagued that generation of the plastic fantastic.  The problems persisted and were never satisfactorily addressed by +General Motors and proudly reside on the list of things to check before buying any of the sixth generation Corvettes.

One of those problems, a truly annoying one and occasionally resulting in costly repairs was the problem with harmonic balancer used on all LS series motors. 

Usually, harmonic balancer is designed with a key way, to fit only one way and prevent securing bolt from loosening over time.  However, this is not what GM Corvette team decided to do at the time when Corvette C5 was introduced.  (+Tadge Juechter was an errand boy on Corvette team, at that time).  Instead, the fine GM engineers decided to go with a HB that had no key way and was designed to be installed using a diamond shape washer and a corresponding bolt.

The decision was without any doubt cost driven, without any reliability considerations whatsoever.

What followed was a true nightmare to the owners, a nightmare that continues to happen until today.  Not surprisingly, the nut would over time, worked itself loose, to the point where HB would wobble noticeably, if the failure went ignored, the collateral damage could be quite costly and if it happened after a warranty expired, lighten up owners wallets considerably.

In spite of huge number of failures that started happening early on during C5 lifecycle, GM ignored the problem and in fact, used the identical design on C6, with exactly same results.  Did GM know about this flaw?  Of course, there were plenty of warranty claims to get even a complete idiot's attention.  Yes, somehow, this problem continued throughout two generations of Corvette.

Fast forward to the seventh generation of Corvette and new HB.  Surprise, surprise,  new HB has a keyway.   Apparently GM figured this one out after all?  Good thing and testimony to the buyers of C7 that GM will address minor issues like engine failures, torque tube failures, differential failures and engine destruction during torque tube R&R?

As a matter of fact, the opposite.  The fact that it took GM TWO Corvette generations to finally deal with seemingly simple problem can damage anyone's confidence that there will be productive upgrades during C7 production duration to eliminate problems already discovered and those that will rear their ugly heads later on.  Ironically enough, C7 car already has a problem related to a key way aka dowel or alignment pins, specifically those that are missing on engine bellhousing and torque tube flange.  Even more ironically, those pins were present on previous generations.  Already, there are numerous thrust bearing damage cases resulting in total engine destruction. 

What does this mean?  What it means is that in spite of claims of "new GM", business of ignoring problems and creating new ones is booming.  What it also means is that even if someone in GM realizes a problem, the actual solution (not dealing with the effect but addressing the cause) is not likely to take place during the duration of the seventh generation of Corvette and most likely not until the NINTH generation will be introduced.

Certainly, not a confidence building corporate strategy and great incentive to shop among other makes to effectively avoid problems with the current Corvette.