(18111723539) - Exhaust Seal Ring (55mm) - 540 (94-95), 740/750 (88-94), 840/850 (91-95) (Genuine BMW) (1 available)

BMW part number 18111723539 (which is interchangeable with or replaced by 18111723531) is a 55mm asbestos-free exhaust gasket/sealing ring.  This high-temperature seal typically crushes into place to prevent leaks at the flange connection where the downpipes interface with the center muffler or catalytic converter assemblies. This 55mm sealing ring is unique to premium, heavy-displacement engines of the late 1980s and 1990s—specifically models equipped with V8 (M60), V12 (M70/S70), or large inline-6 (M30) engines:

5 Series (E34 Generation)

• 540i (M60 V8 engine): 1994 – 1995 

7 Series (E32 Generation)

• 740i / 740iL (M60 V8 engine): 1993 – 1994
• 750iL (M70 V12 engine): 1988 – 1994 

8 Series (E31 Generation Coupe)

• 840Ci (M60 V8 engine): 1994 – 1995
• 850i / 850Ci (M70 V12 engine): 1991 – 1994
• 850CSi (S70 High-Performance V12 engine): 1994 – 1995 

(Note: Certain early E38 chassis 740i/740iL V8 models from 1995–1996 also occasionally catalog this ring at the manifold-to-cat junction depending on build month and market destination). [1]