AEM Cam Gear Failure on SFWD Build
09-14-2014, 05:44 AM
#1
Honda-Tech Member
Thread Starter
AEM Cam Gear Failure on SFWD Build
While tuning my friends SFWD civic, which was making decent power at the time ~790whp, the AEM cam gears he had took a dump on us. At the top of the pull around 8800 rpms the AEM exhaust cam gear literally snapped all the sprockets and came shooting out of the car. i never seen anything like this before. We proceeded to inspect the intake cam gear to see if it was showing any signs of wear and what do you know, the intake cam gear was also on its way out. it had hairline cracks on all of the sprockets. AEM = JUNK. You guys should check your gears just in case yours are also showing signs of failure. FYI the damaged this caused was bent exhaust valves. Thank god the ferreas didn't snap in the block.
FYI i did a search on instagram and i found 2 other similar disaster stories with AEM cam gears. Doodoo product from AEM
FYI i did a search on instagram and i found 2 other similar disaster stories with AEM cam gears. Doodoo product from AEM
09-14-2014, 06:33 AM
#2
Re: AEM Cam Gear Failure on SFWD Build
Nothing new here, heard about these breaking over 10 years ago. AEM at some point made a solid face cam gear, can't see how that one can possibly break, not sure why they went back to this light weight design.
09-14-2014, 07:51 AM
#4
Are you talking about the solid faced 3 bolt tru-time gears? Or a different one. Someone told me the 3 bolts are prone to slipping
09-14-2014, 10:01 AM
#5
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Thread Starter
Re: AEM Cam Gear Failure on SFWD Build
09-14-2014, 10:26 AM
#6
I read about half a dozen threads from long ago and from the sounds of it 99% of slips were due to user error (not torquing them enough, etc) they prob went to the 5 bolt design to reduce user error (more bolts=more clamping force)
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09-14-2014, 02:07 PM
#10
Re: AEM Cam Gear Failure on SFWD Build
Yes the 3 bolt gear, I doubt it would slip if torqued down properly. I've dealt with AEM first hand they seem like good people, they probably won't pay for your engine and will just send you a new cam gear, not that you'll want to use it again...
09-16-2014, 10:37 AM
#11
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Re: AEM Cam Gear Failure on SFWD Build
The older 3 bolt gear was known for failure issues this was over 10 years ago now there newer designs I'm not sure of. Iv used the 3 bolt AEM gears and didn't have a issue but i did have the same thing happen to me with the skunk2 titanium cam gears, they developed hair line cracks that eventually broke apart the gear and ripped my timing belt in half. I was told this can be from over torqing the bolts when adjusting timing on the dyno.
09-16-2014, 01:15 PM
#14
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Re: AEM Cam Gear Failure on SFWD Build
This is scary as I have the exact same cam gears on my car and I am starting to hear a ticking sound coming from my intake cam gear.
09-16-2014, 02:03 PM
#15
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Re: AEM Cam Gear Failure on SFWD Build
Removing a bunch of material from the sprocket to make unique shapes and lighten them decreases strength. I've noticed a lot of these companies ignore certain engineering standards and settle for what looks cool. Look at where the gear failed, it says a lot.
09-17-2014, 03:51 AM
#16
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Re: AEM Cam Gear Failure on SFWD Build
09-17-2014, 05:13 AM
#18
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Re: AEM Cam Gear Failure on SFWD Build
Honestly I don't get why companies make them out of aluminum... sure it's lighter but it's fatigue limit is much lower than that of.a comparable steel alloy. also the added rotational drag from a heavier cam gear is negligible when compared to the weight of the rotating assembly.
When you consider the forces the timing belt places on the camshafts in addition to the force of the valve springs acting against the cam, then toss in high rpm and vibration and it seems silly to use aluminum, especially when companies purposefully and willingly remove material in key structural areas... either for appearance or weight reduction or a combination of both.
it's just like titanium retainers.... they have a finite service life due to tensile strength and fatigue limits. eventually they will break, just like a cam gear.
I think someone needs to start offering a steel alloy based adjustable cam gear that won't slip or break, something that would be more geared towards the high rpm/power crowd.
You could still use a hard anodized aluminum outer section that contacts the timing belt... you don't need a lot of strength in that area and the hard anodizing eliminates most of the wear issues with using softer aluminum. the center section would be steel with 5-6 bolts to lock the two sections together while eliminating any potential slip (high grade ARP hardware would be the logical choice for bolts and washers). I'm not 100% on what alloy would be the best option but even the crappiest grade of steel is stronger than aluminum.
Given the increased strength of steel you could still perform operations to reduce the overall weight of the gear without imparting any structural defects or weak points over those inherent with a similarly designed aluminum gear... all the while still having an attractive product although I think function over form would be the way to go. older gears from companies like Jun and Toda were solid faced and I've never seen one of those fail. also the added machine time to remove material means a higher cost per part.
although the overall price point of a steel gear would be lower than that of an aluminum gear due to the differences in initial material costs (material grade dependent). the biggest cost factor would be machining and tooling costs, mostly due to longer cycle times and slower feed rates based on material hardness.
I think it would be worthwhile to at least look into it, especially when something like a 100 dollar cam gear can prevent tens of thousands of dollars in engine repair/replacement... hell even if the steel gear costs more than an aluminum gear, most likely due to the low volume of sales and the lack of "cool" factor over an aluminum gear, it would still be cheaper than replacing engines and engine components. although you could still anodize or powdercoat the steel gear.
even though AEM will probably tell you to punt I would still inform them of the gear failure. it could be possible that this has happened before and could very well be isolated to one batch of gears that were produced or an inherent design flaw in the product. if they are aware of a decent number of failures similar to yours and it's either a bad batch or manufacturer error they might help with some of the repair costs, especially since this failure happened on an actual "race car" that gets public exposure. I know when parts have failed on the FormulaD cars that run them they have bent over backwards to rectify most issues.
I think they would be more concerned about negativity surrounding their products in a competitive racing environment and the potential sales loss than over the cost of helping you fix the damage. even if it's just sending you new cam gears that you can sell to purchase better units. Although the AEM reps I've spoken to at SEMA and PRI seemed pretty arrogant when it came to their products, even after I told the guy which companies they borrowed technology from and relabeled it as their own (probably a good 75%-80% of their products at least)
just my lengthy and random two cents lol.
When you consider the forces the timing belt places on the camshafts in addition to the force of the valve springs acting against the cam, then toss in high rpm and vibration and it seems silly to use aluminum, especially when companies purposefully and willingly remove material in key structural areas... either for appearance or weight reduction or a combination of both.
it's just like titanium retainers.... they have a finite service life due to tensile strength and fatigue limits. eventually they will break, just like a cam gear.
I think someone needs to start offering a steel alloy based adjustable cam gear that won't slip or break, something that would be more geared towards the high rpm/power crowd.
You could still use a hard anodized aluminum outer section that contacts the timing belt... you don't need a lot of strength in that area and the hard anodizing eliminates most of the wear issues with using softer aluminum. the center section would be steel with 5-6 bolts to lock the two sections together while eliminating any potential slip (high grade ARP hardware would be the logical choice for bolts and washers). I'm not 100% on what alloy would be the best option but even the crappiest grade of steel is stronger than aluminum.
Given the increased strength of steel you could still perform operations to reduce the overall weight of the gear without imparting any structural defects or weak points over those inherent with a similarly designed aluminum gear... all the while still having an attractive product although I think function over form would be the way to go. older gears from companies like Jun and Toda were solid faced and I've never seen one of those fail. also the added machine time to remove material means a higher cost per part.
although the overall price point of a steel gear would be lower than that of an aluminum gear due to the differences in initial material costs (material grade dependent). the biggest cost factor would be machining and tooling costs, mostly due to longer cycle times and slower feed rates based on material hardness.
I think it would be worthwhile to at least look into it, especially when something like a 100 dollar cam gear can prevent tens of thousands of dollars in engine repair/replacement... hell even if the steel gear costs more than an aluminum gear, most likely due to the low volume of sales and the lack of "cool" factor over an aluminum gear, it would still be cheaper than replacing engines and engine components. although you could still anodize or powdercoat the steel gear.
even though AEM will probably tell you to punt I would still inform them of the gear failure. it could be possible that this has happened before and could very well be isolated to one batch of gears that were produced or an inherent design flaw in the product. if they are aware of a decent number of failures similar to yours and it's either a bad batch or manufacturer error they might help with some of the repair costs, especially since this failure happened on an actual "race car" that gets public exposure. I know when parts have failed on the FormulaD cars that run them they have bent over backwards to rectify most issues.
I think they would be more concerned about negativity surrounding their products in a competitive racing environment and the potential sales loss than over the cost of helping you fix the damage. even if it's just sending you new cam gears that you can sell to purchase better units. Although the AEM reps I've spoken to at SEMA and PRI seemed pretty arrogant when it came to their products, even after I told the guy which companies they borrowed technology from and relabeled it as their own (probably a good 75%-80% of their products at least)
just my lengthy and random two cents lol.
09-17-2014, 08:42 AM
#19
Honda-Tech Member
Thread Starter
Re: AEM Cam Gear Failure on SFWD Build
Honestly I don't get why companies make them out of aluminum... sure it's lighter but it's fatigue limit is much lower than that of.a comparable steel alloy. also the added rotational drag from a heavier cam gear is negligible when compared to the weight of the rotating assembly.
When you consider the forces the timing belt places on the camshafts in addition to the force of the valve springs acting against the cam, then toss in high rpm and vibration and it seems silly to use aluminum, especially when companies purposefully and willingly remove material in key structural areas... either for appearance or weight reduction or a combination of both.
it's just like titanium retainers.... they have a finite service life due to tensile strength and fatigue limits. eventually they will break, just like a cam gear.
I think someone needs to start offering a steel alloy based adjustable cam gear that won't slip or break, something that would be more geared towards the high rpm/power crowd.
You could still use a hard anodized aluminum outer section that contacts the timing belt... you don't need a lot of strength in that area and the hard anodizing eliminates most of the wear issues with using softer aluminum. the center section would be steel with 5-6 bolts to lock the two sections together while eliminating any potential slip (high grade ARP hardware would be the logical choice for bolts and washers). I'm not 100% on what alloy would be the best option but even the crappiest grade of steel is stronger than aluminum.
Given the increased strength of steel you could still perform operations to reduce the overall weight of the gear without imparting any structural defects or weak points over those inherent with a similarly designed aluminum gear... all the while still having an attractive product although I think function over form would be the way to go. older gears from companies like Jun and Toda were solid faced and I've never seen one of those fail. also the added machine time to remove material means a higher cost per part.
although the overall price point of a steel gear would be lower than that of an aluminum gear due to the differences in initial material costs (material grade dependent). the biggest cost factor would be machining and tooling costs, mostly due to longer cycle times and slower feed rates based on material hardness.
I think it would be worthwhile to at least look into it, especially when something like a 100 dollar cam gear can prevent tens of thousands of dollars in engine repair/replacement... hell even if the steel gear costs more than an aluminum gear, most likely due to the low volume of sales and the lack of "cool" factor over an aluminum gear, it would still be cheaper than replacing engines and engine components. although you could still anodize or powdercoat the steel gear.
even though AEM will probably tell you to punt I would still inform them of the gear failure. it could be possible that this has happened before and could very well be isolated to one batch of gears that were produced or an inherent design flaw in the product. if they are aware of a decent number of failures similar to yours and it's either a bad batch or manufacturer error they might help with some of the repair costs, especially since this failure happened on an actual "race car" that gets public exposure. I know when parts have failed on the FormulaD cars that run them they have bent over backwards to rectify most issues.
I think they would be more concerned about negativity surrounding their products in a competitive racing environment and the potential sales loss than over the cost of helping you fix the damage. even if it's just sending you new cam gears that you can sell to purchase better units. Although the AEM reps I've spoken to at SEMA and PRI seemed pretty arrogant when it came to their products, even after I told the guy which companies they borrowed technology from and relabeled it as their own (probably a good 75%-80% of their products at least)
just my lengthy and random two cents lol.
When you consider the forces the timing belt places on the camshafts in addition to the force of the valve springs acting against the cam, then toss in high rpm and vibration and it seems silly to use aluminum, especially when companies purposefully and willingly remove material in key structural areas... either for appearance or weight reduction or a combination of both.
it's just like titanium retainers.... they have a finite service life due to tensile strength and fatigue limits. eventually they will break, just like a cam gear.
I think someone needs to start offering a steel alloy based adjustable cam gear that won't slip or break, something that would be more geared towards the high rpm/power crowd.
You could still use a hard anodized aluminum outer section that contacts the timing belt... you don't need a lot of strength in that area and the hard anodizing eliminates most of the wear issues with using softer aluminum. the center section would be steel with 5-6 bolts to lock the two sections together while eliminating any potential slip (high grade ARP hardware would be the logical choice for bolts and washers). I'm not 100% on what alloy would be the best option but even the crappiest grade of steel is stronger than aluminum.
Given the increased strength of steel you could still perform operations to reduce the overall weight of the gear without imparting any structural defects or weak points over those inherent with a similarly designed aluminum gear... all the while still having an attractive product although I think function over form would be the way to go. older gears from companies like Jun and Toda were solid faced and I've never seen one of those fail. also the added machine time to remove material means a higher cost per part.
although the overall price point of a steel gear would be lower than that of an aluminum gear due to the differences in initial material costs (material grade dependent). the biggest cost factor would be machining and tooling costs, mostly due to longer cycle times and slower feed rates based on material hardness.
I think it would be worthwhile to at least look into it, especially when something like a 100 dollar cam gear can prevent tens of thousands of dollars in engine repair/replacement... hell even if the steel gear costs more than an aluminum gear, most likely due to the low volume of sales and the lack of "cool" factor over an aluminum gear, it would still be cheaper than replacing engines and engine components. although you could still anodize or powdercoat the steel gear.
even though AEM will probably tell you to punt I would still inform them of the gear failure. it could be possible that this has happened before and could very well be isolated to one batch of gears that were produced or an inherent design flaw in the product. if they are aware of a decent number of failures similar to yours and it's either a bad batch or manufacturer error they might help with some of the repair costs, especially since this failure happened on an actual "race car" that gets public exposure. I know when parts have failed on the FormulaD cars that run them they have bent over backwards to rectify most issues.
I think they would be more concerned about negativity surrounding their products in a competitive racing environment and the potential sales loss than over the cost of helping you fix the damage. even if it's just sending you new cam gears that you can sell to purchase better units. Although the AEM reps I've spoken to at SEMA and PRI seemed pretty arrogant when it came to their products, even after I told the guy which companies they borrowed technology from and relabeled it as their own (probably a good 75%-80% of their products at least)
just my lengthy and random two cents lol.
Great 2 cents! I want to see what AEM will have to say about this once they receive the cam gear.
09-17-2014, 09:51 AM
#20
Honda-Tech Member
Re: AEM Cam Gear Failure on SFWD Build
honestly this is a super common problem with the aem 5 bolt cam gears....I learned about it and removed mine over a year ago because these threads were popping up all over the place...the d-series ones are known to do it also
not going to bash anyone but a 5 min google search for product reviews would have stopped your buddy from buying them in the first place....
the aem 3 bolt gears are good, the provided bolts suck and strip so replace them with something better
I will say with a company like aem we all expect there products to be top quality, just goes to show you that you can never be to careful
not going to bash anyone but a 5 min google search for product reviews would have stopped your buddy from buying them in the first place....
the aem 3 bolt gears are good, the provided bolts suck and strip so replace them with something better
I will say with a company like aem we all expect there products to be top quality, just goes to show you that you can never be to careful
09-17-2014, 11:25 AM
#21
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Re: AEM Cam Gear Failure on SFWD Build
I would try to find a full faced gear. most of them use at least 5 bolts and I've never heard of the more reputable brands having a slip or failure.
09-17-2014, 12:53 PM
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Re: AEM Cam Gear Failure on SFWD Build
Rocking TODA gears since 2001, and still problem free after about 20 dyno tuning sessions and over 120k on the odo ...LOL
The AEM 5-bolt gears "felt" nice when I was tuning them on customer's cars, but feeling nice and actually working nice are completely different things.
I had witnessed similar problems with the Skunk2 Pro series gear, two cases actually of broken cam gears. Now AEM is on the list as well... damn
The AEM 5-bolt gears "felt" nice when I was tuning them on customer's cars, but feeling nice and actually working nice are completely different things.
I had witnessed similar problems with the Skunk2 Pro series gear, two cases actually of broken cam gears. Now AEM is on the list as well... damn
09-17-2014, 07:27 PM
#25