Exhaust gasket ring part numbers?

[xen0blade]

So, I'm looking at realoem, and there are two different part numbers for the gasket on the rear half of the exhaust: 18101405737 and 18111723379. Does one (the asbestos free one, 18101405737) supersede the other one? Do I need two of each? One of each? Too many part numbers are in my head right now to make sense of this.

[rajicase]

You need one of each. They are different size. 3&4 in the realoem diagram.

[xen0blade]

Thanks! It's amazing how good this forum is for answering technical questions. Here's another: P=NP? (Honestly, if someone answers that question below...then...I..well, I've got nothing.).

[rajicase]

That question cant be answered!

[Das Bullitt]

The asbestos free one is fiberous, the other is a stainless steel type. AFAIK there is not 2 hard metal ones due to the diameter on the fiber one is bigger than that of the hardened steel. Someone can correct me, but that has been my experience.

[hc1001]

Yes they are two different gaskets. I believe one goes around a pipe and the other goes inbetween.

[anotherhaus]

There are threads in various places saying the p/n's you quoted from the rear exhaust diagram are incorrect (I don't have links but you can find them). Apparently tThe correct p/n's can be found in the middle exhaust diagram:

http://realoem.com/bmw/showparts.do?...18&fg=10&hl=31

(13 and 14):

18111719446
18111723720

Though I don't know why there's a 720 and 721...yet another mystery about rear section gaskets.

If you want to wait I have these on order and I'll be able to verify if they're right or wrong in a week or so when I re-do my hangers.

[xen0blade]

There are threads in various places saying the p/n's you quoted from the rear exhaust diagram are incorrect (I don't have links but you can find them). Apparently tThe correct p/n's can be found in the middle exhaust diagram:

http://realoem.com/bmw/showparts.do?...18&fg=10&hl=31

(13 and 14):

18111719446
18111723720

Though I don't know why there's a 720 and 721...yet another mystery about rear section gaskets.

If you want to wait I have these on order and I'll be able to verify if they're right or wrong in a week or so when I re-do my hangers.

DId those end up being the correct part numbers (13/14)?

[anotherhaus]

I believe so. I compared the drivers side ones (since it falls out when you pull the exhaust). They looked the same. I decided to re-use the gaskets since they were undamaged and I ended up being rushed to put the system back together so I didn't test fit the passenger side gasket.

[xen0blade]

OK. I have an official, complete, triple-checked answer. I talked to Pelican Parts yesterday, and called a couple of buddies at BMW this morning, and here's the actual, factual answer: the diagrams are sort of wrong.
18111719446 and 18111723720 are the correct part numbers on the M3. The other two part numbers are because that particular diagram is for the MZ3, not the M3.

[35nhma]

OK. I have an official, complete, triple-checked answer. I talked to Pelican Parts yesterday, and called a couple of buddies at BMW this morning, and here's the actual, factual answer: the diagrams are sort of wrong.
18111719446 and 18111723720 are the correct part numbers on the M3. The other two part numbers are because that particular diagram is for the MZ3, not the M3.

Awesome. Looks like RealOEM may have updated their diagrams to reflect these changes. As of 2024 the gaskets parts are #21 & #22 in the new diagram.

21	Gasket ring asbesto-free	48MM	1			18111723720	$8.37		ENDED
	Required for repair
--	Hex nut wiht flange	M8	2			18307620549
--	Hex bolt	M8X55-8.8	2			07119902957	$5.27
21	Gasket ring asbesto-free		1			18111723721
22	Gasket ring	48MM	1			18111719446	$8.37