Poll: Have you replaced your stock bearings?

[Big boi m5]

Well, I doubt a 6 owner M5 with perfect maintenance would skip such a job when it's seen as so necessary on line.

I have to decide wether the risks outweigh the benefits. I'm not convinced the car won't go to 120k miles without the job, I'm not convinced it hasn't been done, and the job itself looks like it will cost me 1/3rd the value of the car.

On the other hand, is there a better engine than the S65/S85 and what's a few thousand to make it a reliable engine for 50k more miles?

I'll tell you, it's all about what my wife will get more angry at? Spending the money on prevention or the car blowing up?

[pbonsalb]

The car blowing up.

[slicer]

Originally Posted by SleepingBMW

Of course the last hypothesis is the one everyone believes, with in my opinion, less evidence supporting it than the others I listed, which is all S85/S65 engines constantly wear the bearings and they must be replaced every 50-80k miles. If this was the case I think the issue would be as big or bigger as IMS and BMW would have been forced to issue a recall or statement, and we would have seen a lawsuit emerge. You know Lawyers would love to get millions from BMW in a slam dunk case like bad engines. They couldn't do it and deemed it not worthy of their time in a world where they take dozens of cases with low success rates hoping for one home run.

There is a class action lawsuit for rod bearings in process right now. If that's all the proof you need that there's a problem then there you go.

[StrifeM3]

Replaced mine at 100k.

[bigjae1976]

Replaced mine at 57k. I used OEM bearings...kinda wish I did the BE Bearings.

[Helmsman]

Originally Posted by bigjae1976

Replaced mine at 57k. I used OEM bearings...kinda wish I did the BE Bearings.

If the original shells where if decent shape I wouldn't worry about plugging back OEM clearance mate, as engine will be warmed up nicely going forward. I'm sure will take you a long way.

[bigjae1976]

Originally Posted by Helmsman

If the original shells where if decent shape I wouldn't worry about plugging back OEM clearance mate, as engine will be warmed up nicely going forward. I'm sure will take you a long way.

I had the newer tin/aluminum shells so I'm not 100% sure what is good or bad. I've been told that my bearings had quite a bit of wear on them at 57k.

[Helmsman]

Originally Posted by bigjae1976

I had the newer tin/aluminum shells so I'm not 100% sure what is good or bad. I've been told that my bearings had quite a bit of wear on them at 57k.

Had the motor since new or a lot of miles when you took over?

[Big boi m5]

Originally Posted by slicer

There is a class action lawsuit for rod bearings in process right now. If that's all the proof you need that there's a problem then there you go.

Filed in 2016, seemingly lawyer bait, but it does atleast show lawyers were willing to take a chance.

BMW is both denying an issue and targeting mods as the cause.

Anyone else agree that a rod bearing job wouldn't show up in a car fax ?

[Green-Eggs]

Originally Posted by SleepingBMW

Could it be that it's actually disrespecting the break in period that causes the 90% major wear and then poor guys 30-80k miles later reap the consequences as the last 10% minor wear accumulates?

Bearings don't need a break-in procedure and aren't affected by break-in. So abusing the break-in might affect the rings, but won't affect the bearings.

Bearings also don't wear the way you were thinking they do. Over their life, normal rod bearings might wear a few 1/100000 of an inch, maybe 1 or 2/10000 at most. With proper clearance, they shouldn't wear at all, let alone open up by 0.001 inch to normal industry standard specs.

I think there's a second Class Action lawsuit against BMW for RB failure, but I don't have any links for you.

[Big boi m5]

Originally Posted by Green-Eggs

Bearings don't need a break-in procedure and aren't affected by break-in. So abusing the break-in might affect the rings, but won't affect the bearings.

Bearings also don't wear the way you were thinking they do. Over their life, normal rod bearings might wear a few 1/100000 of an inch, maybe 1 or 2/10000 at most. With proper clearance, they shouldn't wear at all, let alone open up by 0.001 inch to normal industry standard specs.

I think there's a second Class Action lawsuit against BMW for RB failure, but I don't have any links for you.

I suppose I have to ask, if the issue was so common, why not address it between S85 and S65? BMW must have not noticed enough cars grenadine or calculated it so low risk that it wasn't worth addressing.

Everyone argues too that the classic engine building rules dictate BMW has to low a tolerance. But why would BMW do this undergraduate level mistake twice?

And you're correct, I know little about engines, but I'm trying to assess risk here the best I can. I have to drive a long way to get this job done under $6k and figure out how to get home and back again. Logistical nightmare for a 1% risk. But worth it for a 30% risk.

Sadly the lawsuits both seem to be exclusively S65 so us M5ers are left to watch and see.

[bigjae1976]

Originally Posted by Helmsman

Had the motor since new or a lot of miles when you took over?

Had the car since new. It has seen a bit of track use and time in cold weather.

[cjm41]

BE bearings ordered, car goes into the shop Wednesday. 80k on the clock.

Will be using OEM bolts with BE bearings after extensive research.

[wfdeacon88]

Originally Posted by cjm41

BE bearings ordered, car goes into the shop Wednesday. 80k on the clock.

Will be using OEM bolts with BE bearings after extensive research.

I'm just curious, why would you use OEM bolts? I did 5 months of extensive research on it prior to my bearing job two months ago... BE bearings and BE-ARP bolts was a no-brainer (from all I came across and discussed with experts)

[Ab28]

Originally Posted by cjm41

BE bearings ordered, car goes into the shop Wednesday. 80k on the clock.

Will be using OEM bolts with BE bearings after extensive research.

Curious as to why OEM bolts?

Everything I've come to know would only lead me to BE-ARP bolts. Did that the first time around on my last E9x.

[wfdeacon88]

Originally Posted by lat77

Curious as to why OEM bolts?

Everything I've come to know would only lead me to ARP bolts. Did that the first time around on my last E9x.

Agreed. To confirm you were referring to the BE-ARP bolts, the ones designed specifically for BE bearings... not just ARP.

[Ab28]

Originally Posted by wfdeacon88

Agreed. To confirm you were referring to the BE-ARP bolts, the ones designed specifically for BE bearings... not just ARP.

Haha Yes. I'll go back and edit that.

[cjm41]

Originally Posted by wfdeacon88

I'm just curious, why would you use OEM bolts? I did 5 months of extensive research on it prior to my bearing job two months ago... BE bearings and BE-ARP bolts was a no-brainer (from all I came across and discussed with experts)

Originally Posted by lat77

Curious as to why OEM bolts?

Everything I've come to know would only lead me to ARP bolts. Did that the first time around on my last E9x.

BE-ARP bolts use ARP2000, which is a weaker alloy than the ARP625 compound which the bolts more commonly referred to as "ARP bolts" are made of.

BE-ARP bolts are as strong as OEM bolts, the difference is that the BE-ARP bolts have an easy torquing process. The only benefit is, they're easy to install, it's up to you if they're worth the extra money. I'm not installing, and the shop told me makes no difference to them.

The traditional ARP bolts are far superior. They are made of the ARP625 compound. They are also significantly more expensive. The downside is that they are the same exact size as OEM bolts but don't account for the difference in torque, resulting in the bolt being driven in just a tiny bit further than they are supposed to in order to meet the torque spec.

This is what the BE-ARP aimed to (and successfully) corrected. However, it's a cheaper alloy than the ARP625.

The confusion lies with the name "ARP" which is the brand name, but people on the forum don't discuss compound.

How do I know? I called ARP and spoke to someone for about 30 minutes.

Why isn't this more widely known? Nobody is hiding it, but people associate "BE" and "ARP" individually with being superior.

This is true... of the BE bearings which correct the clearance issue. It's also correct of the ARP625 bolts which are a superior alloy, and thusly priced accordingly.

BE-ARP (made of ARP2000) are not superior quality to OEM. They are simply easier to torque when installing.

All of this said- you'll all be fine. There are plenty of S65s running around with all sorts of variations. I let my obsessive nature get the best of me and spent a couple days on the phone getting the real story and piecing it all together like a detective. I know all sorts of crap about the inner workings of these companies now as well

I simply chose what I believe to be the most suitable combo of bolts and bearings.

Edit: I'm still somewhat on the fence about not using the ARP625 bolts. Some very reputable people told me the bolt size is a non-issue, and I trust them. However, there are no reported issues with OEM bolts. Therefore I felt the BE bearings and OEM bolts were the most logical combo. That's not to say the BE bearing/ARP625 bolt combo isn't superior/stronger- it is. But they, apparently, aren't 100% perfect.

[pbonsalb]

Absolutely nothing wrong with stock bolts. If you have confidence you mechanic can install rod bearings, he can install stock bolts. No reports of stock bolts failing. But they take longer to install due to the torque sequence so shop’s prefer to to spend more on parts and to let them make more on labor.

[bigjae1976]

The OEM torque sequence isn't bad at all with the right tools.

[IamFODI]

Originally Posted by SleepingBMW

I suppose I have to ask, if the issue was so common, why not address it between S85 and S65? BMW must have not noticed enough cars grenadine or calculated it so low risk that it wasn't worth addressing.

Everyone argues too that the classic engine building rules dictate BMW has to low a tolerance. But why would BMW do this undergraduate level mistake twice?

Not only make the mistake twice, but spend over a decade passing up chance after chance to correct it afterward -- even when they issued updated bearings in 2010.

Those were my questions, too, and others have been asking them for years -- albeit often quietly because of backlash. I can't speak for anyone else, but I've never seen or heard a real answer. Or at least a real answer that withstands a minor rebuttal. Conversations on these points always seem to just dead-end mysteriously.

I've seen two main attempts at an explanation:

1. BMW won't fix it because that'd trigger a lawsuit
2. Tighter clearances can increase power and reduce NVH, and BMW valued those improvements over longevity

The first seems unlikely because, at least in the US, courts don't recognize fixing a problem as evidence of guilt per se because that would disincentivize fixing problems. Plus, companies fix critical problems all the time without being successfully sued. Software/firmware patches for major security vulnerabilities, anyone?

The second, I've actually seen dismissed (apparently unintentionally) by the same person who proposed it on the basis that the hp/NVH differences would be insignificant. And anyway, no one with increased-clearance bearings seems to be reporting less power or more NVH.

Haven't yet seen a response to those rebuttals. I'd be very interested.

Of course, this is all academic in the end. Some years from now, when dozens of S65s and S85s have done 60k-100k+ miles with extra-clearance bearings and been torn down, none of this hand-wringing will have any practical relevance. Either the extra clearance helps with no unwanted side-effects, or it doesn't.

But until then, as you said, we're all just trying to speculate on relative risk, and this kind of open question can weigh pretty heavily.

[Solo_M_Tech]

for everyone saying OE shells are an acceptable solution....


2011 car had 107k Miles with bearing replacement done in 2015 at 81k miles with OE shells and ARP bolts.

26K miles and they were wiped out.

Replaced with the VAC kit with ARP bolts. New owner didn't trust the PO had actually done the service, and had me replace them for security.

Sorry about the poor picture. Didn't think to clean off the bearings before the pic.