I never said "crust" (now famous) removal was the only reason. In your case I'll bet that shaft was at minimum material condition and the elastomeric seal wasn't perfect either, from manufacture and dry shelf lifequote:
My clearest case of leak IMMEDIATELY after installing synthetic oil was a gearbox. I have trouble with the notion of 'crust' on those seals. I'm not talking about input or output shafts, either. I'm talking about a diff lock shaft seal leak. That shaft has not moved since I got the car, and I have a lot of trouble thinking there was oxidized gear oil crust that was disintegrated faster than Obi-Wan Kenobi disappeared when hit with a light saber. That seal weeps on synthetic (only), and it's not even below the static oil level.
First off, nobody said any of my seals were "killed." Just leaking. Second, if you'd read my post carefully, you'd have noticed that (A) I'd used synthetic the entire life of the vehicle; (B) I had no -- repeat, NO -- leaks that entire time; (C) the leaks began 3000 miles into the first change with Redline. Therefore, you'll notice, I never said that synthetics cause leaks, but rather, in my case, I believe Redline caused leaks. Third, as I said, a non-leaking seal is a seal without a problem. Period. If the seal doesn't leak on Monday, and begins leaving drops on the driveway on Tuesday, it was fine on Monday and broken by Tuesday. If continuing with one's existing oil would have meant no leaks for another 50,000 miles, while the switch to Oil X caused, uncovered, precipitated a seal weakness, hyper-cleaned "false seals," whatever ... Oil X caused the leak. We can say that while Oil X may be compatible with seal material A, Oil X may be incompatible with seal material A after so many miles having previously used Oil Y. In other words, your conclusion doesn't matter in the real world. An old seal is not necessarily a "bad" or "damaged" seal, not if it can be maintained functionally using another lubricant. The only other option is for you to insist that the timing was entirely coincidental, which is just silly.quote:
Originally posted by JohnBrowning:
Kev99sl, It is fact not an opion that quality automotive polymers do not react to common automotive oil or or solvents reguardless of their group. If the gasket material reacts that mean that your automotive OEM used low quality, low density junk material!! It is absolutely silly to blame a failed gasket on the oil used since they quite useing all one base type like all PAO with no AN or esters etc....
The seal is either cheaply made or it is damaged. Just becasue you cannot see that it is cheaply made or damaged does not change this fact! If LC,Neutra 131, Auto-RX,B12 Chemtool,MMO,Kerosine etc... do not kill seals or gaskets what makes you think that a lubricant that is made for automotive applications is going to be hard on seal.
If you had a seal or gasket leak after you put synthetic in it was not casued by the synthetic. That seal or gasket was already damaged. If you contact gasket or seal manufactures or polymer manufactures they can confirm this.
Maybe synthetic didn't CAUSE the conditions that can lead to a leak...quote:
Good discussion, but I stand by my statement. Even when the oil is pouring out as fast as you pour it in did the synthetic oil really CAUSE the leak by destroying the seal? Wearing the moving metal shaft at the seal? I mean REALLY BE THE CAUSATIVE FACTOR? I have to again say: Nope!
You say this, and yet you also say:quote:
Originally posted by sands:
I mean, really this is a pointless technical play on words deciding weather are not synthetic "caused" the leak...
Oh ok, well how about this. The seals deteriorated while using dino oil. Therefore, dino oil causes leaks. Ridiculous? Yes, but not a whole lot more than saying that although synthetic did not damage the seals in the first place, it leaks through the damaged seals, so therefore it caused the leaks.quote:
Originally posted by sands:
So I guess we can say that the leak was caused by the synthetic, but the areas damaged resulting in a leak were not caused by the synthetic.
quote:
Originally posted by acewiza:
So maybe we should re-phrase the statement and say "synthetic oil leaks better than dino oil?"