B pillar crack prevention

E28 technical advice asked and given! Troubleshooting, modifications and more.
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pavulon
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B pillar crack prevention

Post by pavulon »

As my search for a terrific E28 slogs on (and on), Ivo mentioned an issue which I did not realize to be a concern. B pillar cracking. Short of a rollcage sort of solution, is there an established reinforcement in which this issue can be effectively avoided or remedied? Were all E28s vulnerable or were some more (or less) likely to crack?

Thanks in advance.
Mike W.
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Re: B pillar crack prevention

Post by Mike W. »

I don't think any reasonable action can prevent it. However for whatever reason I used to hear about that in the early days of Mye28, but I haven't heard about it in a while. You'd think as the cars get older it would be more of an issue, but it doesn't seem like it. One data point, my '85 had not cracked when I sold it with 330K on it. And not usually, but on occasion, it saw hard cornering and brisk travel on dirt roads. YMMV.
AnalogGuy
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Re: B pillar crack prevention

Post by AnalogGuy »

I've been around many e28's since they were new and have never seen or heard of a b-pillar cracking. I'm guessing what someone is referring to is the b-pillar trim at the interior. These commonly get beat up (cracked ?) by the seatbelt buckle not retracting fully. It's always a good idea to be sure the buckle isn't loose before you shut the door. If you go to 10 parts cars you'll see most of the b-pillar inside trim panels damaged.
kojo96
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Re: B pillar crack prevention

Post by kojo96 »

AnalogGuy wrote:I've been around many e28's since they were new and have never seen or heard of a b-pillar cracking. I'm guessing what someone is referring to is the b-pillar trim at the interior. These commonly get beat up (cracked ?) by the seatbelt buckle not retracting fully. It's always a good idea to be sure the buckle isn't loose before you shut the door. If you go to 10 parts cars you'll see most of the b-pillar inside trim panels damaged.
This isn't what the op was talking about. Reference was to the body/chassis developing structural cracks at the top of the B pillar, where it meets the roofline.
RonW
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Re: B pillar crack prevention

Post by RonW »

On most cars that joint has a large radius. On the E28 (and I assume the E12) the radius is very small, making it susceptible to stress fractures.
SlickDizzy
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Re: B pillar crack prevention

Post by SlickDizzy »

By this point I would guess most E28s that are not garage queens (and probably a few that are) have the B-pillar crack, and people just don't realize it.

You could probably attempt to mitigate the issue with front & rear strut braces to reduce the torsional forces the body experiences (or complete some thorough seam welding if you're really hardcore) but ultimately I think it is what it is.

Even if that area wasn't prone to cracking the E28 would still be awful in side-impact collisions, which is where all cars improved multiple orders of magnitude through the 90's.
LeiseyJr
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Re: B pillar crack prevention

Post by LeiseyJr »

Mine hasn't cracked yet. Seen it on others, but I personally believe they were in a heavy collision at one point. Adding a rollcage would stop it from cracking...
Ju@n
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Re: B pillar crack prevention

Post by Ju@n »

SlickDizzy wrote:By this point I would guess most E28s that are not garage queens (and probably a few that are) have the B-pillar crack, and people just don't realize it.

You could probably attempt to mitigate the issue with front & rear strut braces to reduce the torsional forces the body experiences (or complete some thorough seam welding if you're really hardcore) but ultimately I think it is what it is.

Even if that area wasn't prone to cracking the E28 would still be awful in side-impact collisions, which is where all cars improved multiple orders of magnitude through the 90's.
My guess is you're probably right, since the cracking starts in the inside part and then spreads to the outside.
Mine has the crack on both sides, I've been about to fix it a thousand times but never got around to it, from what I've been told the correct way to do it is to reinforce it from within the pillar with a small plate.
I'm not sure that that would be a solution that would last forever but I guess it's better than nothing
HayekFan
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Re: B pillar crack prevention

Post by HayekFan »

My car (210k miles) doesn't seem to have the crack, although I'm not positive I'm looking in the right place. I wonder if cars with upgraded, stiffer suspensions might be more prone to it, since presumably they'd have more forces being transmitted to the chassis.
SlickDizzy
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Re: B pillar crack prevention

Post by SlickDizzy »

HayekFan wrote:My car (210k miles) doesn't seem to have the crack, although I'm not positive I'm looking in the right place. I wonder if cars with upgraded, stiffer suspensions might be more prone to it, since presumably they'd have more forces being transmitted to the chassis.
My own presumption is that it's not related to either stiff suspension or collision damage, as my old Euro 528i with stock suspension that had never been in an accident was cracked on both sides by 200k.

I'd guess it's more related to torsional loading. Ever driven a car onto a steep slope (such as a driveway) at an angle from the street? Basically, a situation where both back wheels are on level ground but the front wheels are very unevenly loaded?

A good buddy of mine used to have such a driveway leading to his garage. We knew a guy with a third gen Camaro and we would always make fun of him because you could hear the whole damn car creak and flex from 20 feet away as he turned onto the slope due to its awful rigidity.

While you couldn't hear it like the Camaro, what I didn't tell anyone was that I could always feel the E28 pretty obviously doing it too. I was always worried it'd crack the windshield from the way it seemed to be flexing :oops:
HayekFan
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Re: B pillar crack prevention

Post by HayekFan »

SlickDizzy wrote:I'd guess it's more related to torsional loading.
And since torsional loading is related to suspension, we sort of get back to my point, which is that suspension may be a factor.
cek
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Re: B pillar crack prevention

Post by cek »

Someone please post a pic of a cracked B-pillar. KThxbai.
Dana in Reno
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Re: B pillar crack prevention

Post by Dana in Reno »

I've never heard of this problem before. All of my E28s have creaked on rough roads, but no sign of cracking on my 535is at 225,000. I'd be very interested to see a picture.
Ju@n
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Re: B pillar crack prevention

Post by Ju@n »

Open the door (driver), where the pillar meets the roof you'll see a hairline crack, check closely
Bonsaibacker
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Re: B pillar crack prevention

Post by Bonsaibacker »

Something else to worry about... Pictures appreciated.
SlickDizzy
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Re: B pillar crack prevention

Post by SlickDizzy »

Sadly the pictures I used to know of in a prior thread that showed B-pillar cracking are now apparently gone due to the Photobucket fiasco. :roll:

Often you'll see cracked paint where the B-pillar meets the roof with a line of rust underneath where the roof starts. Sometimes you can't spot them from the outside but they are obvious when the pillar trim is removed and you look up near the headliner.
dsmith
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Re: B pillar crack prevention

Post by dsmith »

My M5s had cracks. One big enough for a fingernail. 528e’s did not. Half of my 535i’s did. More power and aggressive driving equals more cracks.
David B
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Re: B pillar crack prevention

Post by David B »

My 85 535 has a prominent crack on the drivers side B pillar. I assumed it was due to the car having been rolled at one point back in the 90’s.
taavipa
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Re: B pillar crack prevention

Post by taavipa »

Took some close-ups of my passenger side B-pillar today. I didn't find any cracks there.

View from the outside
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Diagonal view from front
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View from the inside
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Might actually be something different but I figure there are three panels joined together there.
Image

Image

A would be the outer B-pillar panel that covers the rocker on the bottom.
C is a reinforcement panel that runs by the roofline on the inside, visible on the previous photo.
B is inner B-pillar panel that continues as upper beam. Down below it continues as (outer) rocker panel.
A and B are brazed together on top (yellow line).

Is it the brazed joint that gives in?

Please feel free to download any of the photos above to mark where the crack would be.
cek
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Re: B pillar crack prevention

Post by cek »

This was Minerva after beings stripped ('85 euro 528i chassis):

Image

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Image

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This is the best pic I can find post body work that shows how they re-enforced that area. I have no idea if this will actually help because even back then I'd never seen a picture of the actual failure:

Image
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