Chain housing O-ring. Porsche 964 / 993  ❭  99970728840

Chain housing O-ring, 6 x 2.5 mm  
This original Porsche O-ring is used in the chain housing / oil bridge sealing area, helping prevent oil leaks and maintain correct sealing around the timing chain housing assembly.
Sold individually

Fits:
Porsche 964 1989 - 1994
Porsche 993 1994 - 1998

Diagram ref no 22

What This Part Does / Functions
•  Seals the chain housing / oil bridge connection
•  Helps prevent engine oil leaks
•  Supports correct sealing around the timing chain housing area
•  Helps maintain clean and reliable engine operation
•  Replaces a hardened, flattened, cut or leaking original O-ring
•  Provides correct OE Porsche size, material and fitment
•  Supports correct reassembly after chain housing or oil bridge service
•  Helps maintain factory engine sealing performance.

Why Replace This Part?
O-rings are exposed to engine oil, heat, pressure and age-related hardening. Over time, the seal can flatten, crack, swell or lose elasticity. Once the chain housing or oil bridge area has been disturbed, the O-ring should normally be replaced to ensure a reliable seal when reassembled. Replacing it with a Genuine Porsche OE chain housing O-ring helps prevent oil leaks and supports correct engine sealing.

Common Symptoms of a Failed Chain Housing O-Ring
•   Oil leak around the chain housing area
•   Oil residue near the oil bridge or chain tensioner area
•   Persistent seepage after previous engine work
•   Hardened, flattened or cracked O-ring during inspection
•   Oil smell from hot engine components
•   Oil drips underneath the vehicle
•   Seal damage after chain housing service
•   Need to reseal the oil bridge / chain housing connection.

When to Replace This Part
•   When removing or refitting the chain housing components
•   During chain housing, oil bridge or chain tensioner service
•   If oil leakage is traced to the chain housing sealing area
•   If the O-ring is hardened, flattened, cracked or damaged
•   During engine rebuild or top-end repair
•   When replacing related timing chain housing sealing components
•   After separating the oil bridge from the chain housing

Where It Fits on the Car
This O-ring fits in the engine chain housing / oil bridge sealing area. It is used around the timing chain housing system on the flat-six engine and helps seal the oil passage connection where specified. Correct installation is important. The sealing surfaces should be clean, and the O-ring should be fitted without twisting, pinching or damage.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99970728840

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