Synthetic Causes Bearing Cavitation
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Novice
Joined: Nov 2006
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Synthetic Causes Bearing Cavitation
Was talking to a local Indy (denver) and he told me that synthetic oil is causing the main inner bearing to cavitate and the bearing goes out.
So I am thinking Fooey.
He goes on to say that the oil is so slippery that the bearing simply stops rotating and a flat spot is created. But this only happens at certain speeds/rpm's when the cruise control is locked and at highway speeds. He took me to the back room and showed me a bearing/crank on a bike this happened to. Showed me 9 other bikes that were in because of this happening to them.
So, my question is - has ANYONE else heard of such a thing anywhere in these here United States that might possibly confirm such a bold statement?
So I am thinking Fooey.
He goes on to say that the oil is so slippery that the bearing simply stops rotating and a flat spot is created. But this only happens at certain speeds/rpm's when the cruise control is locked and at highway speeds. He took me to the back room and showed me a bearing/crank on a bike this happened to. Showed me 9 other bikes that were in because of this happening to them.
So, my question is - has ANYONE else heard of such a thing anywhere in these here United States that might possibly confirm such a bold statement?
Cruiser
Joined: Dec 2007
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RE: Synthetic Causes Bearing Cavitation
I talked to an independent wrench yesterday that indicated the same thing but for different more understandable reasoning. He indicated that the H-D synthetic is not holding up to the heat of the engine and the lubricant is breaking down prematurely. He strongly recommends a good quality 20W-50 for the engine and I didn't catch what he recommended for the trans and clutch. I know the engine runs hot I have measured 260 oil temp just off the show room floor, it has cooled down some now that it is semib-broken in. He also showed me a couple of engines that he claimed as victims of the H-D syn. I have been a fan of syn but wonder if it is just H-D syn if there is really anything to it. Strange two different independent wrench's in different areas come up with the same thing for different reasons? Hmmmmm
Tourer
Joined: Jun 2007
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RE: Synthetic Causes Bearing Cavitation
That's an old one - search thru this forum and you'll surely find many saying bull$hit. It's from back in the day before the MoCo came out with it's own syn blend.
Try this Google search, too. Mostly junk, but a couple discussing (or dismissing) this question.
Be careful with this indy, he's a bit behind the times....
Try this Google search, too. Mostly junk, but a couple discussing (or dismissing) this question.
Be careful with this indy, he's a bit behind the times....
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Novice
Joined: Nov 2006
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RE: Synthetic Causes Bearing Cavitation
No worries - I am more than careful with him - I do my own work where I can and would never let him touch my ride.
I am running Mobil 1 which I put in a bit prematurely (IMO) at about 2500 miles on a new ring job. Have about 5k on her and don't plan on looking back unless something comes up bad when I run a static comp check on her.
Odd though that he has 10 bikes in his shop all run on what he claimed is synthetic oil having all bad crank bearings.
I am running Mobil 1 which I put in a bit prematurely (IMO) at about 2500 miles on a new ring job. Have about 5k on her and don't plan on looking back unless something comes up bad when I run a static comp check on her.
Odd though that he has 10 bikes in his shop all run on what he claimed is synthetic oil having all bad crank bearings.
Cruiser
Joined: Apr 2007
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RE: Synthetic Causes Bearing Cavitation
Boy does that bring back memories . . . LOL
Yup, according to HD, until they came out with their own that is, synthetics were toooo slippery and will cause bearings to skate. The last thing I heard wasduring Sturgis, 2001 IIRC,just before HD came out with Syn3. At the Civic Center in Rapid City some 'factory rep' was talkng about the new bikes. Someone asked about synthetic oil and the rep said the "oil passasges in the TC were tooooo small" (see there is some consistency) and synthetic oil would clog the passages. I told the rep he was a phuckin idiot and I was invited to leave.
I've been running synthetic oil for well over 20 years in everything I own. I run 20-50 in the engine and primary and 75-110 in the transmission. I put about 10k on a year and I change theengine and primary once a year and the transmission every third time.
That being said I don't see how you can take a 20-50 motor oil, a 10-40 motor oil (which is essentially what the HD primary lube was) and a 75-90 gear lube (totally different SAE testing) and blend it into one lubricant. I know there was a tech tip or service bulletin (CRS) that came out addressing foaming problems withSyn3.
Bottom line is I think any quality synthetic is fine (Amsoil, Mobil 1, Redline, etc) I don't think Syn3 is a quality product. I wouldn't use it in lawn mower.
Yup, according to HD, until they came out with their own that is, synthetics were toooo slippery and will cause bearings to skate. The last thing I heard wasduring Sturgis, 2001 IIRC,just before HD came out with Syn3. At the Civic Center in Rapid City some 'factory rep' was talkng about the new bikes. Someone asked about synthetic oil and the rep said the "oil passasges in the TC were tooooo small" (see there is some consistency) and synthetic oil would clog the passages. I told the rep he was a phuckin idiot and I was invited to leave.
I've been running synthetic oil for well over 20 years in everything I own. I run 20-50 in the engine and primary and 75-110 in the transmission. I put about 10k on a year and I change theengine and primary once a year and the transmission every third time.
That being said I don't see how you can take a 20-50 motor oil, a 10-40 motor oil (which is essentially what the HD primary lube was) and a 75-90 gear lube (totally different SAE testing) and blend it into one lubricant. I know there was a tech tip or service bulletin (CRS) that came out addressing foaming problems withSyn3.
Bottom line is I think any quality synthetic is fine (Amsoil, Mobil 1, Redline, etc) I don't think Syn3 is a quality product. I wouldn't use it in lawn mower.
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Road Master
Joined: Aug 2005
Posts: 765
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From: Alleghany Co., NC and SW Florida
RE: Synthetic Causes Bearing Cavitation
Yep AND masturbation causes blindness!
Who is your Indy? Sister Mary Elephant at St. Scooter's????
Dave ain't here man!
[IMG]local://upfiles/3789/5357636119194864948FB8D3770EFC65.jpg[/IMG]
Who is your Indy? Sister Mary Elephant at St. Scooter's????
Dave ain't here man!
[IMG]local://upfiles/3789/5357636119194864948FB8D3770EFC65.jpg[/IMG]
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Road Warrior
Joined: Dec 2005
Posts: 1,817
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From: MONTGOMERY,AL.
RE: Synthetic Causes Bearing Cavitation
Simply that is the biggest BS i have heard. Being an independent he probably has not kept up with the latest schools or tech changes. Alot of ol timers say that.
Banned
Joined: Mar 2007
Posts: 3,706
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From: Woodstock, Ont , Can
RE: Synthetic Causes Bearing Cavitation
Bearings fail for lots of reasons and oil isn't one of them. If an oil supposedly so slippery that it can't get traction to roll how the hell can it grind a flat spot on it. Misaligned bores jamming the bearings is likely the cause by reducing it's clearances. They jam and then skate.
Ron
Ron