Crank Pulley
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Crank Pulley
My vette is one that falls in the "affected vin numbers" ,but I have not had any problems............YET!! I am very concerned about this and very upset. Does anyone know that the correct torque for the Crank bolt suppose to be?? I guess I have no choice but to monitor it every week for as long as I own it, Sounds pretty dumb that GM will not recall these cars.
I have absolutely no confidence in taking the car to far from home or to have a little free spirited driving ( Red line once in a while ) that is one of the reasons we buy vettes, right?
P.S. She was born in August '04 and 2600 miles on the clock.
I have absolutely no confidence in taking the car to far from home or to have a little free spirited driving ( Red line once in a while ) that is one of the reasons we buy vettes, right?
P.S. She was born in August '04 and 2600 miles on the clock.
Last edited by spectra6.0; Apr 28, 2005 at 06:56 AM.
Racer
Joined: Nov 2004
Posts: 332
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From: Switzerland
I am also in the affected range (VIN#9260) and I don`have a problem either ........yet. I have around 1300 Miles now and since the car hit 500 Miles I have taken the car to redline at least 20 times.If it happens well then they have to fix it. So drive it hard now and if it fails , well then. Better than babying the car now and then it happens after 10 000 miles or more.
Burning Brakes
Joined: Feb 2001
Posts: 892
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From: Houston Texas
You use a spare crank bolt and torque it to 240 ft.lbs. Its purpose is to make sure the harmonic balancer is fully seated on the crankshaft and up against the crankshaft sprocket. Then you remove that crankbolt, install a new bolt and torque it to 37 ft.lbs. Then turn it an additional 140 degrees. Its a torque-to-yield bolt. The whole purpose of using 2 bolts is to make sure youre getting an accurate torque when installing the second bolt and not using it to seat the balancer and torque it at the same time.
The problem is that you cant get a socket on it because the steering rack is in the way. If youre mechanically inclined at all, you could fix all this yourself by yanking the steering rack and pinning the balancer. You would never have another problem out of it and you wouldnt have to let the dealership people have their hands all over your vette. I would hate having a car knowing that its a potential bomb while driving around. That has to suck to always have that thought of "I wonder when its going to come off" in the back of your head. If that balancer does come off, its going to cause alot more damage. That balancer is also what rides against the front seal in the timing cover which prevents oil from coming out.
The problem is that you cant get a socket on it because the steering rack is in the way. If youre mechanically inclined at all, you could fix all this yourself by yanking the steering rack and pinning the balancer. You would never have another problem out of it and you wouldnt have to let the dealership people have their hands all over your vette. I would hate having a car knowing that its a potential bomb while driving around. That has to suck to always have that thought of "I wonder when its going to come off" in the back of your head. If that balancer does come off, its going to cause alot more damage. That balancer is also what rides against the front seal in the timing cover which prevents oil from coming out.
Melting Slicks
Joined: Nov 2004
Posts: 2,514
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From: Orwigsburg Pa.
I agree with the drive it hard now mentality. If it fails they fix it. A guy sent me a PM that he had the ''meltdown'' this past Saturday on a track entering a sweeping turn at 100 mph and through he lost his power steering he was able to bring the car to rest. He is going to post details . There has now been close to 20 failures reported on this forum . Alot of guys like to convince themselves that this problem is ''isolated'' and it may be. But we only get a small percentage of the 11,000 owners that fall in the vin range that use the forum. If one were to extrapolate to all owners in that range there could be a significant number indeed.I will say that I have two thousand miles on mine since the 2nd fix and I have driven the car like a Corvette. I do feel for you guys who are in the ''what if'' and ''when'' mode. Some guys have demanded a proactive fix--the new washer etc and had it done.
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Was at the BB last week and the engineers looked at my car (I'm in the vin window) and said my belt is just starting to fray. I've got just over 3000 miles on the car including a 2 day Evolution School where we drove the car hard both days.
Called the dealer and he's ordering the parts and we'll have the job done in a couple of weeks.
Will be glad to put the pin back in this grenade!!!
Called the dealer and he's ordering the parts and we'll have the job done in a couple of weeks.
Will be glad to put the pin back in this grenade!!!
Le Mans Master
Joined: Aug 2004
Posts: 6,412
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From: Bluffton, SC
GM has been using this type of crank pulley bolt for many years with no major problems. The consensus among GM mechanics I've spoken with is that the fewer than 90 reported failures for the C6 can be traced back to one assembly/work station at an engine plant. Of course GM will not publically admit that.
The crank pulley failure has, at this point, affected fewer than 1% of the cars in the VIN range before the new washer was added. That's not much consolation if you're one of that 1%, but it's not likely to be seen by the vast majority of C6 owners. Personally, I check my belt every month and have painted a reference mark on the bolt so any movement can be seen.
With one or two exceptions, all the failures have occurred during the first 2,000 miles. A failure beyond that point, while not impossible, is extremely unlikely. Personally, I wouldn't hesitate to take my own C6 on any trip, anywhere.
The crank pulley failure has, at this point, affected fewer than 1% of the cars in the VIN range before the new washer was added. That's not much consolation if you're one of that 1%, but it's not likely to be seen by the vast majority of C6 owners. Personally, I check my belt every month and have painted a reference mark on the bolt so any movement can be seen.
With one or two exceptions, all the failures have occurred during the first 2,000 miles. A failure beyond that point, while not impossible, is extremely unlikely. Personally, I wouldn't hesitate to take my own C6 on any trip, anywhere.
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Thread Starter
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Joined: Oct 2004
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Originally Posted by StanNH
GM has been using this type of crank pulley bolt for many years with no major problems. The consensus among GM mechanics I've spoken with is that the fewer than 90 reported failures for the C6 can be traced back to one assembly/work station at an engine plant. Of course GM will not publically admit that.
The crank pulley failure has, at this point, affected fewer than 1% of the cars in the VIN range before the new washer was added. That's not much consolation if you're one of that 1%, but it's not likely to be seen by the vast majority of C6 owners. Personally, I check my belt every month and have painted a reference mark on the bolt so any movement can be seen.
With one or two exceptions, all the failures have occurred during the first 2,000 miles. A failure beyond that point, while not impossible, is extremely unlikely. Personally, I wouldn't hesitate to take my own C6 on any trip, anywhere.
The crank pulley failure has, at this point, affected fewer than 1% of the cars in the VIN range before the new washer was added. That's not much consolation if you're one of that 1%, but it's not likely to be seen by the vast majority of C6 owners. Personally, I check my belt every month and have painted a reference mark on the bolt so any movement can be seen.
With one or two exceptions, all the failures have occurred during the first 2,000 miles. A failure beyond that point, while not impossible, is extremely unlikely. Personally, I wouldn't hesitate to take my own C6 on any trip, anywhere.
Stan ,
You said that you would not hesitate taking a trip, I assume that your Vette does fall in that affected range?? I'm just trying to gain a little confidence back. I have 2,600 miles but still very concerned. Have not visited red line too often, but will be brave and start on a more regular basis. About painting a mark across the bolt and on the Crank, that sounds like a good idea that I will do today. What did you use?
-Thanks
Race Director
Joined: Oct 2004
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Originally Posted by spectra6.0
So if put a torque wrench on the crank bolt (the original bolt, without removing or replacing it.) I should see it torqued to 37 ft. lbs. without any movement from the bolt??
In other words, the bolt is supposed to be tighter than all get out. It has to be to prevent the harmonic dampener from slipping on the crank snout, because there is no key. With the older style keyed dampeners, the crank bolt only needed to be tightened to about 140 ft-lbs (exact value not important). But with only a friction fit, it has to be *tight* to avoid slippage under inertia loads, and ultimate unscrewing of the bolt. (Once the dampener starts slipping on the crank snout, it unscrews the bolt.)
Note that the bolt is supposed to be so tight that you have to jam a bar into the teeth of the flywheel to keep the engine from turning over before you can get the bolt tight.
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From: www.EXOTICVETTE.com - FL Cruise-In VI, VII, & VIII
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St. Jude's Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
I've noticed excessive (in my opinion) belt noise on my C6. Could this me an indicator at just about 1000 miles? Will check that VIN # and see if it's in the range. I know my C5 had a noisey tension pulley and it annoyed me.... hoping the C6 isn't just naturally noisey!?!?
Race Director
Joined: Jan 2005
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From: Daytona Beach FL
Originally Posted by spectra6.0
I noticed at idle the crank pulley wobbles just a little, is this normal???
I don't even know if I'd want to drive it to the dealer, unless he's real, real close.
Bob
Race Director
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Originally Posted by spectra6.0
I noticed at idle the crank pulley wobbles just a little, is this normal???
Thread Starter
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Originally Posted by shopdog
Depends on what you mean by "a little". Pulleys are rarely machined perfectly, and there's always going to be a little runout (looks like wobble to the casual eye). That's normal. Actual wobble, though, would be a very bad thing.