[Shon]

Doing suspension install and found this on top the shock mount where it connects to chassis. Usually there is a gasket (part #5) but I cannot find this part on realoem. Is this OEM part?

[weehe126]

#5 is almost a paper gasket, real thin. That pic of your part doesn't look OEM to me.

[Wolf 335]

I believe that part is oem. Maybe it was discontinued at one point.

You can see it in my pic when I did my front struts it is there.




Additionally it can be seen on the schematic that they had some part similar to this plate. Looks like its grayed out



And furthermore, from the Bentley repair manual...

[feuer]

Originally Posted by weehe126

That pic of your part doesn't look OEM to me.

Originally Posted by Wolf 335

I believe that part is oem. Maybe it was discontinued at one point.

Exactly! Absolutely OEM

[feuer]

Originally Posted by Shon

. Usually there is a gasket (part #5) but I cannot find this part on realoem. Is this OEM part?

OEM Part Number: 31306772226

[Shon]

Thanks everyone. I remember the reinforcement plates on e46 but didn't know why it was on my car. I put it back the same way it was.

[weehe126]

Good to know, I just had the paper gasket on my E90.

[Tim603]

My car came with that reinforcement plate as well, they have been discontinued. That being said there have been reports of that part of the unibody "mushrooming" so if you have the reinforcement plate I would recommend running it

[feuer]

Originally Posted by Tim603

My car came with that reinforcement plate as well, they have been discontinued. That being said there have been reports of that part of the unibody "mushrooming" so if you have the reinforcement plate I would recommend running it

Share the info on this. I would like to see. It was a problem on previous generations 3-series.

[Tim603]

Originally Posted by feuer

Share the info on this. I would like to see. It was a problem on previous generations 3-series.

I think bmw discontinued them because they didn't see it was truly a problem but personally I would rather be safe than sorry. When I was doing all my suspension stuff I did some research, found the same thing about previous 3 series gens, mayyyybe found some examples on our chassis but can't really remember.

I decided to keep mine for reinforcement purposes because...why not? Rather be safe than sorry is the way I look at it. If your car doesn't have them you can always get the turner ones.

https://www.ecstuning.com/b-turner-m...es/tsu9075str/

[feuer]

Originally Posted by Tim603

I think bmw discontinued them because they didn't see it was truly a problem but personally I would rather be safe than sorry. When I was doing all my suspension stuff I did some research, found the same thing about previous 3 series gens, mayyyybe found some examples on our chassis but can't really remember.
I decided to keep mine for reinforcement purposes because...why not? Rather be safe than sorry is the way I look at it. If your car doesn't have them you can always get the turner ones.
https://www.ecstuning.com/b-turner-m...es/tsu9075str/

OEM aren't strut tower reinforcement plates as they are exactly the same size as the strut mount. They are actually for the strut mounts. BMW change the material used through out the years. If you pull up part numbers you will see that pre LCI and LCI have different part numbers what is physically/measurement wise identical parts. No issues with strut tower on e9x to my knowledge what so ever.

[Tim603]

Originally Posted by feuer

OEM aren't strut tower reinforcement plates as they are exactly the same size as the strut mount. They are actually for the strut mounts. BMW change the material used through out the years. If you pull up part numbers you will see that pre LCI and LCI have different part numbers what is physically/measurement wise identical parts. No issues with strut tower on e9x to my knowledge what so ever.

I know you know how load distribution works. That plate distributes the load over a larger surface area thus reinforcing the strut tower sheet metal. Its basically the same as the turner reinforcement plates just with a little less surface area.





Also OP I believe the part you are referring to is #3 in this diagram which has been discontinued.

[feuer]

Originally Posted by Tim603

I know you know how load distribution works. That plate distributes the load over a larger surface area thus reinforcing the strut tower sheet metal. Its basically the same as the turner reinforcement plates just with a little less surface area.

Ok, I will bite. Let's have discussion. Why OEM didn't go wider than strut mount? Like Turner plate and OEM plates for 46 ? Would not that be more efficient load distribution? If you compare e46 non M and M3 strut mounts you will see that the non M are similar to e90 and the reinforcement plates shape and size is similar (larger) to M3 strut mounts. BMW made it like that proactively because the m3 had stiffer suspension.

[Tim603]

Originally Posted by feuer

Ok, I will bite. Let's have discussion. Why OEM didn't go wider than strut mount? Like Turner plate and OEM plates for 46 ? Would not that be more efficient load distribution? If you compare e46 non M and M3 strut mounts you will see that the non M are similar to e90 and the reinforcement plates shape and size is similar (larger) to M3 strut mounts. BMW made it like that proactively because the m3 had stiffer suspension.

Well seeing how beefy the E90 M3 strut mounts are they probably just did it for good measure. It may not be wider than the strut mount but still provides reinforcement. Even on the Bentley manual its listed as a reinforcement part. I'm guessing they eventually deemed it unnecessary or not critical for structural integrity so they discontinued it and stopped using them.

That being said I'm still running mine as it does add structural integrity and would rather be safe than sorry. Overkill? Possibly lol but why not is the way I look at it

[feuer]

Originally Posted by Tim603

Well seeing how beefy the E90 M3 strut mounts are they probably just did it for good measure. It may not be wider than the strut mount but still provides reinforcement. Even on the Bentley manual its listed as a reinforcement part. I'm guessing they eventually deemed it unnecessary or not critical for structural integrity so they discontinued it and stopped using them.

That being said I'm still running mine as it does add structural integrity and would rather be safe than sorry. Overkill? Possibly lol but why not is the way I look at it

Yes, I know e9x M3 strut mounts are beefy and they are larger outside diameter (compare to non M) just like the e46 m3 strut mounts and the e46 reinforcement plates. Having more contact area on the inside diameter will be a lot less effective than having more area on the outside diameter.

[Shon]

I decided not to install them to lower the front end a tad bit more paired with lowering perches. Strut mount is definitely more beefier than the e46 and roads in Atlanta aren't bad plus M3 strut bar has a plate on top.

[feuer]

Originally Posted by Shon

I decided not to install them to lower the front end a tad bit more paired with lowering perches. Strut mount is definitely more beefier than the e46 and roads in Atlanta aren't bad plus M3 strut bar has a plate on top.

I hope you replaced the strut mounts because old and collapsed mounts will come in contact with the lowering perch under load.

[Shon]

Originally Posted by feuer

I hope you replaced the strut mounts because old and collapsed mounts will come in contact with the lowering perch under load.

Sure did. They were due for replacement.