Official S65 Rod Bearing Condition Example Thread

Helmsman wrote

...Or is it a given for a shop to take one shell from each bag per rod?

I alluded to this a couple posts up. Shops doing these jobs should be measuring each shell during assembly to catch any irregularities and to ensure quality. Unfortunately however, I might suggest that a number (majority?) of techs around the country fall into the category of "parts changers" and don't understand the intricacies of the topic and just plug and play whatever they pull out of a box.

The coined term "You don't know what you don't know" comes into play here. I also suggest that for too many in the automotive industry, the Dunning Kruger Effect applies. See attached image.

deansbimmer wrote

Machines cannot consistently and 100% without fail produce bearings that are all exactly .000X of each other. There must be a process of selection prior to packaging.

All bearing manufacturers measure shells as they're packed, in one way or another. It is a mandatory step in the production process when dimensions down to the ten-thousandths must be known. Some brands capitalize on their process and advertise them to portray a sense of superiority. For example, KING trademarked theirs as "Bulls Eye Tolerance".

ACL offers "Graded Sets" for some engines, but I've not seen much literature from ACL regarding their process for our engines. Based off of measurements I've encountered it's obvious however that they must be measuring and matching shells for each set.

Here is another fun article from KING's Dr. Dmitri Kopeliovich about bearing wall consistency. King has published some of the best literature about bearing design and production. http://www.kingbearings.com/wp-content/uploads/2015/07/consistency-aera.pdf

Thanks again Coulter (nice page btw!). Interesting read, so that tigher production curve of King's improve their yield, while it doesn't necessarily improve shipped product depending on what variance they decide to ship I guess?

Anyhow, ACL commit to a certain shell variance (0.008mm). When you've found that they match the pair within a box delivery, do you mean the individuall shells could be outside of the max/min thickness to still achieve total variance? That would seem strange in my view as they wouldn't honor the per shell variance (and dangerous as you say when mixed up). While once shells are measured to be within spec'd 0.008mm intervall they could on the other hand simply pack them together with no further fuzz? Or are they making the effort to match within the variance to further tighten the total (i.e. like BE).

Sorry to keep shasing you mate but we're eager to learn!

Thanks,
Nik

deansbimmer wrote

I alluded to this a couple posts up. Shops doing these jobs should be measuring each shell during assembly to catch any irregularities and to ensure quality. Unfortunately however, I might suggest that a number (majority?) of techs around the country fall into the category of "parts changers" and don't understand the intricacies of the topic and just plug and play whatever they pull out of a box.

The coined term "You don't know what you don't know" comes into play here. I also suggest that for too many in the automotive industry, the Dunning Kruger Effect applies. See attached image.

Haha, I'm finding myself in the valley of dispair! Slowly working my way up though with your good help...
Ps. Realize bummer to spend all this time but hopefully gives good mktg in return. Web page in the signature..?

Helmsman wrote

Anyhow, ACL commit to a certain shell variance (0.008mm). When you've found that they match the pair within a box delivery, do you mean the individuall shells could be outside of the max/min thickness to still achieve total variance? That would seem strange in my view as they wouldn't honor the per shell variance (and dangerous as you say when mixed up). While once shells are measured to be within spec'd 0.008mm intervall they could on the other hand simply pack them together with no further fuzz? Or are they making the effort to match within the variance to further tighten the total (i.e. like BE).

I don't recall any falling outside acceptable limits but there were certainly variances that could have yielded minimal clearances if certain packs within sets were mixed with certain others. From a manufacturing standpoint, falling within tolerance still doesn't negate the need to measure and batch shells properly before shipping. Its the basic tolerance stack issue.

2013 E92 M3, original owner
7500 oil changes w/ OEM oil
111,500 miles

RB top by Quest4Six, on Flickr

RB bottom by Quest4Six, on Flickr

tbone28 wrote

2013 E92 M3, original owner
7500 oil changes w/ OEM oil
111,500 miles

RB top by Quest4Six, on Flickr

RB bottom by Quest4Six, on Flickr

They actually don't look that terrible compared to others with less mileage. But 111k miles for a 2013? Definitely not driving mine enough.

It seems to have got lucky with the journal and shells measures!

Teufel_Hunden wrote

They actually don't look that terrible compared to others with less mileage. But 111k miles for a 2013? Definitely not driving mine enough.

it's a daily driver

tbone28 wrote

Teufel_Hunden wrote

They actually don't look that terrible compared to others with less mileage. But 111k miles for a 2013? Definitely not driving mine enough.

it's a daily driver

Being in Maryland I just don't drive mine a lot in the winter. I just went over 47k miles, so I have some catching up to do.

teufel_hunden wrote

being in maryland i just don't drive mine a lot in the winter.

[Laughs in winter tires and rust]

Mine is my winter beater. I use snow wheels here in NH. Yes, the salt and moisture will eventually kill the car, but I will enjoy it in the meantime. Had my 08 for 9 of its 12 years and it’s got a lot of life left.

Teufel_Hunden wrote

They actually don't look that terrible compared to others with less mileage. But 111k miles for a 2013? Definitely not driving mine enough.

They actually do look terrible, don't let those dark spots fool you.

tdott wrote

Teufel_Hunden wrote

They actually don't look that terrible compared to others with less mileage. But 111k miles for a 2013? Definitely not driving mine enough.

They actually do look terrible, don't let those dark spots fool you.

Standing alone, no they don't look good. But I've seen ones that look much worse with half the mileage.

Teufel_Hunden wrote

tdott wrote

Teufel_Hunden wrote

They actually don't look that terrible compared to others with less mileage. But 111k miles for a 2013? Definitely not driving mine enough.

They actually do look terrible, don't let those dark spots fool you.

Standing alone, no they don't look good. But I've seen ones that look much worse with half the mileage.

A shiny turd is still a turd.

Teufel_Hunden wrote

Standing alone, no they don't look good. But I've seen ones that look much worse with half the mileage.

That means nothing and doesn't make this type of wear is acceptable in any way.

tdott wrote

Teufel_Hunden wrote

Standing alone, no they don't look good. But I've seen ones that look much worse with half the mileage.

That means nothing and doesn't make this type of wear is acceptable in any way.

I agree, it does not.

2011 M3 DCT @75,300 miles. Shop said bearings are worn, but nothing outrageous. Looking back at dealer maintenance records from previous owners, this car has gone 15k miles between oil changes a couple times. :

jvictormp wrote

Guys, ECS's got BE Bearings with ETA February 7th.

ECS let me down, I bought the bearings on Feb 4th, since the ETA in stock was Feb 7th. When it was Feb 7th, the ETA was modified to Mar 12th.

Wonder what happens in the stores that it's so difficult to manage the stock.

chutak wrote

2011 M3 DCT @75,300 miles. Shop said bearings are worn, but nothing outrageous. Looking back at dealer maintenance records from previous owners, this car has gone 15k miles between oil changes a couple times. :

15k OCI

chutak wrote

2011 M3 DCT @75,300 miles. Shop said bearings are worn, but nothing outrageous. Looking back at dealer maintenance records from previous owners, this car has gone 15k miles between oil changes a couple times. :

Long OCIs will not necessarily be detrimental to bearings. Modern synthetics are very robust. Oil filters do an excellent job. Unless there is a massive fuel dilution problem, synthetics provide excellent protection for long OCIs. An example of how well modern synthetics hold up is super-late-model racing. The Chev 604s V8 engines (400HP, 400ftlb) in use get an oil change once per season. And, while they red-line at only 6000RPM, they live their life at WOT.

Most people, myself included, change their oil way more often than needed. Oil analysis can tell you how much life is left in the oil. Most people do not sample prior to changing due to the headache and costs involved. I know I sure do not want to fiddledick around to get a sample out of my S65 and then pay for the shipping and analysis. And fresh oil is pretty cheap insurance - as long as you don't:

• forget to put oil in the engine
• put the wrong oil in the engine
• under fill the oil
• over fill the oil
• forget to change the filter
• forget to tighten the filter
• use the wrong filter
• forget to replace the filter gaskets
• forget to put the pan plugs in
• under torque the pan plugs
• over torque the pan plugs
• forget to put the oil cap on

Yikes

That said, I have seen some horror stories due to long oil change intervals - but the problems were usually sludge in the heads, not bottom end issues. And this was in environments with really long, cold winters (think Minnesota but colder), short city commutes and use past 12 months.

Happy motoring and keep the foot to the floor.

Just got my bearings done by AutoCouture Motoring. My M3 is a 2013 with 49,xxx. I'm surprised with how my bearings looked, but I got them replaced with BE Bearings and ARP bolts so no more RB worries.

Yea the alu bearings usually come out looking like that, including the wavy pattern.
Apparently it's down to the way the babbitt layer is applied.