Locked Up Timing Chain
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Melting Slicks
Joined: Nov 2010
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From: On the east coast we drive until we die
Locked Up Timing Chain
I had my engine rebuilt due to a failed lifter eating my cam. During the disassembly, the shop found the timing chain was locked up. They said they'd never seen one lock up before and said it was on the verge of failing. It was a double roller but I'm not sure on the brand. Is the chain locking up a normal preface of a failure or could it be contributed to something else?
I upgraded the chain but my concern is did the chain almost fail because it was faulty, because of the lifter/cam failure, or was it something else which may happen again? It was a H/C LS2 with an UDP, which I know gets referenced alot in timing chain failures. There was about 30k miles on this build so I would think I the chain was faulty it would have broke sooner. I'm wondering if the cam being eaten by the lifter affected the chain.
I'd appreciate any theories or info on timing chain failures.
I upgraded the chain but my concern is did the chain almost fail because it was faulty, because of the lifter/cam failure, or was it something else which may happen again? It was a H/C LS2 with an UDP, which I know gets referenced alot in timing chain failures. There was about 30k miles on this build so I would think I the chain was faulty it would have broke sooner. I'm wondering if the cam being eaten by the lifter affected the chain.
I'd appreciate any theories or info on timing chain failures.
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I had my engine rebuilt due to a failed lifter eating my cam. During the disassembly, the shop found the timing chain was locked up. They said they'd never seen one lock up before and said it was on the verge of failing. It was a double roller but I'm not sure on the brand. Is the chain locking up a normal preface of a failure or could it be contributed to something else?
I upgraded the chain but my concern is did the chain almost fail because it was faulty, because of the lifter/cam failure, or was it something else which may happen again? It was a H/C LS2 with an UDP, which I know gets referenced alot in timing chain failures. There was about 30k miles on this build so I would think I the chain was faulty it would have broke sooner. I'm wondering if the cam being eaten by the lifter affected the chain.
I'd appreciate any theories or info on timing chain failures.
I upgraded the chain but my concern is did the chain almost fail because it was faulty, because of the lifter/cam failure, or was it something else which may happen again? It was a H/C LS2 with an UDP, which I know gets referenced alot in timing chain failures. There was about 30k miles on this build so I would think I the chain was faulty it would have broke sooner. I'm wondering if the cam being eaten by the lifter affected the chain.
I'd appreciate any theories or info on timing chain failures.
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,626
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From: On the east coast we drive until we die
Good question. The chain is very stiff and needs to be deliberately bent to change shape. Picture how a normal bicycle chain just flops around. My timing chain is almost solid. Now I have never actually handled a timing chain before so I have no idea how they're supposed to be but based on the concern for its condition, I'm assuming it's not supposed to be stiff?
Safety Car
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From: Opelika Alabama
Good question. The chain is very stiff and needs to be deliberately bent to change shape. Picture how a normal bicycle chain just flops around. My timing chain is almost solid. Now I have never actually handled a timing chain before so I have no idea how they're supposed to be but based on the concern for its condition, I'm assuming it's not supposed to be stiff?
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From: St. Louis, MO
St. Jude Donor '08
Good question. The chain is very stiff and needs to be deliberately bent to change shape. Picture how a normal bicycle chain just flops around. My timing chain is almost solid. Now I have never actually handled a timing chain before so I have no idea how they're supposed to be but based on the concern for its condition, I'm assuming it's not supposed to be stiff?
Thread Starter
Melting Slicks
Joined: Nov 2010
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From: On the east coast we drive until we die
That's a possibility. Certainly the valvetrain issues I was having would contribute to it......?
I just checked my paperwork. The double roller chain has about 20k miles on it. The underdrive pulley is an ASP installed close to 9 years and 40k miles ago. I can't see that contributing to it after all this time.
Here's a link to the chain...if it works
as a side game, you can try and guess what states/countries I'm making
I just checked my paperwork. The double roller chain has about 20k miles on it. The underdrive pulley is an ASP installed close to 9 years and 40k miles ago. I can't see that contributing to it after all this time.
Here's a link to the chain...if it works
as a side game, you can try and guess what states/countries I'm making
Last edited by 5knives; Feb 15, 2016 at 03:17 PM.
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From: St. Louis, MO
St. Jude Donor '08
The video is unlisted, you might want to switch it to public.
I have to admit that looks too tight based on my experience, a link chain might be that tight but not a roller. I'm interested to see what others think.
What type of balancer did you have? Did you have the ls2 style dampener or ls3?
By the way, if you hold your phone sideways your videos will be 1080p and will fill the screen on a computer or TV.
I have to admit that looks too tight based on my experience, a link chain might be that tight but not a roller. I'm interested to see what others think.
What type of balancer did you have? Did you have the ls2 style dampener or ls3?
By the way, if you hold your phone sideways your videos will be 1080p and will fill the screen on a computer or TV.
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Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,626
Likes: 195
From: On the east coast we drive until we die
The video is unlisted, you might want to switch it to public.
https://youtu.be/nYdNOVCSFQc
I have to admit that looks too tight based on my experience, a link chain might be that tight but not a roller. I'm interested to see what others think.
What type of balancer did you have? Did you have the ls2 style dampener or ls3?
By the way, if you hold your phone sideways your videos will be 1080p and will fill the screen on a computer or TV.
https://youtu.be/nYdNOVCSFQc
I have to admit that looks too tight based on my experience, a link chain might be that tight but not a roller. I'm interested to see what others think.
What type of balancer did you have? Did you have the ls2 style dampener or ls3?
By the way, if you hold your phone sideways your videos will be 1080p and will fill the screen on a computer or TV.
My paperwork does not mention anything about a balancer/dampener so I have no idea. Is there one version more commonly used or a certain type of build which would require one over the other?
Last edited by 5knives; Feb 15, 2016 at 03:53 PM.
Tech Contributor
Joined: Jul 2002
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From: St. Louis, MO
St. Jude Donor '08
No but try it as I suggested next time. You'll be happy.
There is a brand of dampener that has been associated with timing chain breaks but I don't recall which brand off the top of my head.
There is a brand of dampener that has been associated with timing chain breaks but I don't recall which brand off the top of my head.
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,626
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From: On the east coast we drive until we die
I'll check with my shop. I'm assuming the stock dampener is not recommended?
I just find it too much of a coincidence the chain locked up after my valvetrain issues.
Tech Contributor
Joined: Jul 2002
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From: St. Louis, MO
St. Jude Donor '08
Stock dampener is fine - some folks have problems with them coming apart but most are just fine. There was a problem with a certain under drive dampener and pulley breaking timing chains.
Here's some info...
https://www.corvetteforum.com/forums...ster-link.html
Here's some info...
https://www.corvetteforum.com/forums...ster-link.html
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,626
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From: On the east coast we drive until we die
The shop said it was most likely lack of oil, wrong oil, or a manufacturer's defect. With 20k+ miles on the chain, I'm more inclined to think it was oil starvation. Nod to CMYSIX for his guess. I've always used either Mobil1 or Amsoil 5w30 but I'll be going to Amsoil Zrod 10w30 exclusively now. So, would my failed lifter eating the cam contribute to the oil starvation or was there something else in the works?
The shop also said my balancer looked fine but I can upgrade to an ATI just to be safe if I wanted to. Wish I thought of this before the motor was back together and in the car. Faulty balancers and UDPs cause the chain to snap or stretch, which wasn't the case here, so I'm debating whether to bother with the swap now. (brainstorming out loud)
<edit> Going back and forth with my shop through texts so information is coming in slowly. They don't think the lifter issue had anything to do with a lack of oil since it was only 1 lifter out of 16 that failed. So I'm not sure what the deal with the chain was then. Possibly a manufacturer defect after 20k miles?
The shop also said my balancer looked fine but I can upgrade to an ATI just to be safe if I wanted to. Wish I thought of this before the motor was back together and in the car. Faulty balancers and UDPs cause the chain to snap or stretch, which wasn't the case here, so I'm debating whether to bother with the swap now. (brainstorming out loud)
<edit> Going back and forth with my shop through texts so information is coming in slowly. They don't think the lifter issue had anything to do with a lack of oil since it was only 1 lifter out of 16 that failed. So I'm not sure what the deal with the chain was then. Possibly a manufacturer defect after 20k miles?
Last edited by 5knives; Feb 15, 2016 at 05:42 PM.
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,626
Likes: 195
From: On the east coast we drive until we die
Stock dampener is fine - some folks have problems with them coming apart but most are just fine. There was a problem with a certain under drive dampener and pulley breaking timing chains.
Here's some info...
https://www.corvetteforum.com/forums...ster-link.html
Here's some info...
https://www.corvetteforum.com/forums...ster-link.html
So my question now is, what happened to lock my chain up and how can I avoid it on my new one? Which is a stronger version. Or was it really just a freak thing?
Tech Contributor
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From: St. Louis, MO
St. Jude Donor '08
Thanks for the link Joe. Depending on the quote I get for an ATI installed, I may just keep my current balancer for now since it has never given me any problems and I was inspected and approved during the rebuild.
So my question now is, what happened to lock my chain up and how can I avoid it on my new one? Which is a stronger version. Or was it really just a freak thing?
So my question now is, what happened to lock my chain up and how can I avoid it on my new one? Which is a stronger version. Or was it really just a freak thing?
I would find out what brand your balancer is... if it's the brand in that thread, that's only one of many threads on the subject, and I would definitely change it. There was a video of a timing chain in action and those things form into an S upon deceleration, it's important to have the proper tensioners in there (I've seen ls3 tensioners break). A proper balancer
You also have to clearance some engines/oil pump/covers to use some double roller chain like you are using, I'm sure your shop knows that and did it.
As to why it's tight, the chain is open to the oil pan and I've never seen an oil related problem with a timing chain, so I don't think that is it. Manufacturing defect is one potential issue (I'd call the manufacturer and see what they say) or a bad balancer could cause it to do this - it causes them to break...whether they get tight before they break, I don't know.
Thread Starter
Melting Slicks
Joined: Nov 2010
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From: On the east coast we drive until we die
What engine is this? LS1, 2, 3, 6 or 7?
I would find out what brand your balancer is... if it's the brand in that thread, that's only one of many threads on the subject, and I would definitely change it. There was a video of a timing chain in action and those things form into an S upon deceleration, it's important to have the proper tensioners in there (I've seen ls3 tensioners break). A proper balancer
You also have to clearance some engines/oil pump/covers to use some double roller chain like you are using, I'm sure your shop knows that and did it.
As to why it's tight, the chain is open to the oil pan and I've never seen an oil related problem with a timing chain, so I don't think that is it. Manufacturing defect is one potential issue (I'd call the manufacturer and see what they say) or a bad balancer could cause it to do this - it causes them to break...whether they get tight before they break, I don't know.
I would find out what brand your balancer is... if it's the brand in that thread, that's only one of many threads on the subject, and I would definitely change it. There was a video of a timing chain in action and those things form into an S upon deceleration, it's important to have the proper tensioners in there (I've seen ls3 tensioners break). A proper balancer
You also have to clearance some engines/oil pump/covers to use some double roller chain like you are using, I'm sure your shop knows that and did it.
As to why it's tight, the chain is open to the oil pan and I've never seen an oil related problem with a timing chain, so I don't think that is it. Manufacturing defect is one potential issue (I'd call the manufacturer and see what they say) or a bad balancer could cause it to do this - it causes them to break...whether they get tight before they break, I don't know.
Looks like I'll be upgrading to an ATI. What a waste, the engine just went back together. That thread makes a few mentions of the chain links tightening up so am I too assume that is a preface to a full on failure? Looks like I was in for a rebuild no matter what. At least I wasn't stranded anywhere though. What does an ATI installed go for these days?Your guess is as good as mine. For a second I had no idea what the hell you were talking about. Then I realized my own stupidity.
Last edited by 5knives; Feb 15, 2016 at 08:27 PM.
Tech Contributor
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From: St. Louis, MO
St. Jude Donor '08
I was afraid of that when I read your symptoms.
Only bright side is you caught it now instead of blowing up three engines like that other guy.
I don't know on price; it's a bit of a job as you have to remove the rack.
Only bright side is you caught it now instead of blowing up three engines like that other guy.
I don't know on price; it's a bit of a job as you have to remove the rack.
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Melting Slicks
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From: On the east coast we drive until we die
I know it's just aggravating when it could have easily been taken care of during the rebuild for only the cost of the balancer. I can't blame the shop since the same pulley has been on there for close to 9 years and 40k+ miles without issue. But something was going to inevitably happen whether it was a defect in the chain or the balancer. Honestly it was just me brainstorming about why it happened and if precautions were taken to prevent it in the future. I guess sometimes overthinking things is good.
Thread Starter
Melting Slicks
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From: On the east coast we drive until we die
Does anyone know what the functionality difference is between the aluminum and steel dampers are? Also, any reason not to go with another underdrive version?