Crankshaft Balancer

[Don.Williams]

Well, another surprise. My '98 C5 has about 31,000 miles on it. About a month ago I started hearing noise up front, and it increased to the point that my wife could hear me approaching from a block away.

I couldn't find the problem and took it to a non-dealer repair shop. He took the front accessory drive belt off and the noise went away. He put the belt back on and the noise returned.

Then he rubbed chalk on the ribbed section of the belt and the noise went away for a few hours.

The bottom line is that the crankshaft harmonic balancer, the one which drives the belt, has allowed the pulley section to shift and it wobbles, making the noise. It also wears out belts.

I called around San Diego and found it is a known and common problem, but again it is not one recognized by GM.

It would be interesting to see the ratio of harmonic balancers purchased by Corvette compared to the number of matching C5's produced to date.

My guess, based on a random sample of repair shops and dealers, it that about 5% of the C5's out there have or will have or someday will have this problem.

Oh yes, the repair cost is around $450 for parts and labor. The part itself costs $125.00.

The reason the labor is so high is that the power steering gear, the power steering cooler, both drive belts, and the starter motor have to be removed in order to get to the balancer.

Then you have to do some fancy marking in order to set up the new balancer to match the setup of the old balancer if it was modified during production.

It is indeed a major project to replace it. Check it out in the '98 factory manual, starting on page 6-93.

And of course, this happens after the car is out of warranty.

Am I the only one with this problem?

 

[Don.Williams]

:Twist

Forgot to mention that the complete process for replacing the crankshaft balancer for the '98 C5 starts on page 6-93, jumps to page 6-174, and finally to page 6-308. These are all under "Engine Mechanical".

My feeling is that the factory repair manuals have become more difficult over the years, and this is the 4th Vette (and repair manual set) I have had.

One more comment. Due to the tolerences specified in the manual, this is a project which requires special tools.

:nono

THIS IS NOT A DO-IT-YOURSELF PROJECT!

 

[ZZRider]

No problems with my 99.

Then again I only had it a year and ~18,000mi before the mods started including a stroker (different crank/balancer/etc). I have really not heard much about this being a common problem before. What I have heard is that the balancer is really only pressed onto the crank, not keyed. This became a problem when the supercharger applications became available. Most, including myself, have them keyed on (or use locking dowels) for such a project.

 

[Don.Williams]

No key is correct.

They are pressed on, and it takes 4 separate press steps to put it back on the crankshaft.

According to the manual it also takes special tooling to do the press-on steps. Of course one could probably put something together to do it but it's interesting that the factory manual goes into such detail for the installation process.

In fact, it tells you to use the old bolt for the first of the three steps, then switch to the new bolt.

 

[redvett]

crankshaft balancer

I would highly reccomend you take your car to the dealer and if they dont want to fix it call customer assistance. ( The phone number is in the back of your owners manual) I know i got them to replace a complete engine on my 1985 in 1990.

 

[Don.Williams]

Thanks redvett,

The customer assistance number is useless for situations like this. All they do is access your repair records at the dealer and if there is no record of a problem report (and there won't be in this instance) they tell you it's just too bad. A problem report is only entered into the computer when the dealer writes up a repair order. If it's just a note on the pad and they don't do any work, no record is made.

In this case I only noticed the problem recently, somewhat above 31,000 miles.

I wouldn't be so upset if I hadn't checked around at some independent shopt and learned that it was a pretty common problem.

As far as the dealer is concerned, the car is out of warranty and he has refused to give my any way to contact someone in the Corvette service chain who can address the issue.

I can report that I finally got a call from someone at GM who has promised to call back in a few days.

I'm just bothered by the difference in the treatment I get with my $50,000 Corvette and the treatment my wife gets with her $40,000 Mercedes. The Mercedes dealers seem to care.

The Corvette dealer I bought this last car from has only two claims to fame, he sells more Corvettes than any other dealer in the area, and he always sells at list price or higher.

Oh yes, one more thing. Whenever you have service done there, you get a call from the dealer asking you to give them high marks on the Satisfaction Survery you get from Chevrolet.

 

[redvett]

Keep calling and ask to talk to a superviser. The squeeky wheel gets the grease. Did you get the name of the person who called you that is who is handling your case. As far as your dealer is concerned they are worthless since they wont help you at all. Try another one.

 

[Don.Williams]

Yup,

I got a name, 800 number, and extension.

He initially called about the parking brake problem because I had filed a complaint with Autoline, but I think he is adding the balancer to the inquiry.

[Friday I went in for my new drivers license. I didn't have to take a driving test. When you do take the test you have to demonstrate that the brakes, horn, mirrors, parking brake, etc. all work. My parking brake would have failed me if I had taken a driving test with the car before I fixed it last week.]

I had just adjusted the parking brakes myself since it looked like I was heading down a blind alley with Chevrolet. As it turns out, some C5's never had their adjusters extended from the install position so my parking brake never worked. My adjusters were screwed to the collapsed position.

And I agree about the dealers. They don't seem to care much one way or the other. I once bought a new Z car and it had transmission problems. After taking it in for service 4-5 times, I took the issue to Autoline and got little satisfaction. It was my word against the dealers. When I decided to trade the car in, the guy at that same dealership who did the test drive asked "What's wrong with your transmission, it seems to grind when you shift?" There's more to the story but you get the point I'm sure.

Yes, I will keep trying. There is no excuse for these kinds of problems on such an otherwise well-designed car.

Thanks,

DAW

 

[redvett]

Re: Crankshaft balancer

You have to remember the people that answer the customer assistance line have no authority and just record your complaint. A far cry from the Corvette Action Center where they would get it fixed.
Good luck and keep us posted.

 

[Don.Williams]

Thanks redvett-

I know about the Customer Assistance Line. All they do is look at
the dealer records but they don't have the ability to even understand technical issues.

I do have another number. How can I tell whether that is the Action Center or not?

Thanks,

DAW

 

[redvett]

The Action Center is no longer in operation. Just keep calling and complaining about your problem and they will get someone involved. You know (the squeeky wheel gets the grease)

 

[Don.Williams]

Thanks,

G.M. did reply by phone a couple of days ago. They said they had contacted the dealer and the dealer would give me a 10% discount on the repair. That's 10% off of something around $450.00.

This car already had one in-warranty recall, very early on, which replaced the belt tensioner for the belt in question, to fix a clanking noise. It didn't fix anything but the dealer said that was the best Corvette had to offer.

The clanking noise was caused by the belt slipping under high load and jerking the tensioner around. It sounded to the driver like it was coming from the tunnel but it was actually coming from the engine.

Now I wonder whether that tensioner problem, which has existed from day one, caused the slippage of the outer portion of the balancer.

DAW

 

[cruzer99]

Don, It is not uncommon with Chevy's to have the harmonic balancer to seperate over time. This has been a problem that I have read about over the last 20 years. I'm not saying it right, but it's something to watch for over time.

 

[Don.Williams]

:BOW

This whole story turnes out to have a happy ending, for me at least.

I finally got the Corvette regional manager involved and the dealer asked me to bring the car in for a look.

Although the balancer still seems to have excessive wobble, they determined that it was not loose and had not moved. They did, however, do the following, all at no cost to me:

New main belt tensioner system [This is a new design]
New main serpentine belt
New Alternator and pulley
New Vibration damper [Both new design]
New A/C belt idler pulley
Replaced 2 exhaust system hangers which were causing muffler rumble

Turned all 4 brake rotors
Adjusted brakes and parking brake
Measured parking brake lining, good as new, no wear

Total cost for the above: $0.00

I checked and found that the dealer and GM shared the cost of all this, which would normally run around $1,000.00.

I paid them to change the brake fluid just to be sure there was no moisture accumulation.

Both the dealer and I agree that my Vette is now the quietest one they have worked on and I am very happy.

 

[redvett]

Don,
Sounds like you got eveything you needed done. It certainly was worth your time to complain to GM they sure took care of you.

 

[hawaii-5-lo]

sounds like someone told the dealer,better take care of that customer.my 99 doesnt wobble yet 37,000 miles.the other good thing is they told you it was o.k.which means its documented,so if all heck breaks loose from the balancer,maybe they will have to fix that too.
Todd.

 

[Don.Williams]

The lessons I learned are:

1. Regardless of what you tell the service writer, and regardless of the notes he takes, if he doesn't get your concerns into the computer there will never be any record of any un-resolved complaints you made while the car was in-warranty.

2. You do have to continue to press reasonable issues. The fact is that the brake pulsation problem had been reported and they had already replaced one of the belt tensioners in response to a service bulletin. The tensioner was supposed to stop a knocking sound which came at full steering wheel (maximum power steering pressure, such as when backing out of the garage, etc.), but it didn't fix the problem.

I would not ever press any issues unfairly, but in this case I felt everything I had had been reported during the warranty period. (Reported, but not recorded was actually what happened).

The dealers send out a service satisfaction survey after every visit, and if every item is not checked as "completely satisfied" they have to deal with the regional managers. They have called me twice to remind me of this but so far no survey has been received, so I don't know what might have caused them to drop the ball in this instance. In this case I am completely satisfied and feel they went out of their way do their best.

I still see wobble in the balancer pulley, but we'll just have to wait and see whether it ever really moves. Guess I should go mark it with a paint stripe.

The interesting thing is that the independent repair shops say that slipping pulleys are common on that model, and it's cousins, whereas the dealer says he has never seen one.

I guess it's all in where you are coming from.

Thanks again for the responses from everyone.

 

[kpic]

No problems with my 99.

Then again I only had it a year and ~18,000mi before the mods started including a stroker (different crank/balancer/etc). I have really not heard much about this being a common problem before. What I have heard is that the balancer is really only pressed onto the crank, not keyed. This became a problem when the supercharger applications became available. Most, including myself, have them keyed on (or use locking dowels) for such a project.

They are pressed. Same as you, I replaced mine with an ATI Super Damper which is pinned with a single dowel. Single shear strength for a 1/4" dowel is 7360#; double is 14720#. If it ever sees 7360#; a lot more will fail first.

Also replaced the alternator-P/S bracket with a 2003-2005.
From A&A's instructions: "There are two styles of alternator power steering brackets. Chevrolet changed the design in 2003. The early style is very weak and will most likely break. The new style is much stronger. They are about $95 at your dealer. Make sure you have the later style. The following picture shows the difference. (GM# 12578068)"

According to the tuner, it is about 50-50 and I didn't care to learn which 50% I was in; so I paid ~$65 + S&H at GM parts direct.

As you stated, this is for SC loads and not required otherwise.