Quote:
Originally Posted by Doc Oc
I just did mine as well. They looked much worse than yours. Yours are the best I've ever seen here. It's nice to know you won't be chewing up the new bearings anytime soon. I also had split motor mounts coincidentally.
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Yea, glad to see you caught yours in time bro! And with the motor mount fixed your car should drive a good deal smoother, too. I actually replaced my passenger side tourn mount 2 months ago, and that made a world of difference while also cured a previously unfixable steering wheel vibration at freeway speed. Now with the driver side changed as well, she drives good as new
Quote:
Originally Posted by BMRLVR
I was just speaking to one of my engine guy peers and he pointed out something that made a lot of sense after I thought about it. So please read some food for thought I have written below.
The bearings in this thread are the new 702/703 bearings that were introduced sometime in 2010 production year cars. Since these bearings are Aluminium/tin bearings they are going to show wear much differently than the older 088/089 lead/copper/steel bearings. Basically since there is no soft lead (Babbitt) overlay on these 702/703 bearings they will not look as bad as the 088/089 bearings even if they are experiencing the same type of operating condition.
So when you see these newer lead free bearings that "look" better after being in an engine for an equal mileage as the old lead/copper/steel bearings, you are only seeing the additional surface hardness of the bearing shell better able to take contact from the crank journal in boundary lubrication conditions caused by breakdown in the hydrodynamic lubrication in the bearing. A better looking bearing shell doesn't mean a better functioning bearing, the lubrication issue, which I believe is insufficient clearance, still needs to be addressed to actually correct the bearing issue.
One big issue I can see with these newer bearings is increased chance of crank journal damage due to the harder surface of the shell.
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save some of your time arguing with the naysayers, we all make our own decisions and some simply don't believe it, or care, and that's fine. They're not interested in the additional information, and I certainly don't give a rats ass about their 2 cents. Also keep in mind that many folks are still under original warranty or covered by CPO/3rd party policies, so less worries for them, too. I think what you said above is one of the reasons I felt like sharing mine bearing swap outcome, as there have been few reports on S65s with the non-lead based bearings. I too share the belief that the engines that has seized/broke due to BF are truly in the minority %, but I have also heard of 2011+ failures from local shops; broken engine is not small things people joke about. Maybe or hopefully it is true that the new bearings are better able to take contact and withstand wear. Since mine is a high mileage engine that was supposedly built with the newer bearings, and I decided to take out my insurance policy on it, just figured I post it up and add to the record book. If my results instill confidence in owners that the 702/703 bearings are stronger and will last much longer, and therefore make them less nervous about post June 2011 built S65s, that's great too