Timing Chain. Porsche 996 GT3 / 997 GT3  ❭  95910555201

Chain tensioner adjuster. 
The OE Match timing chain adjuster (also known as a chain tensioner adjuster) is an engine timing component used in Porsche 964 and Porsche 993 models. These adjusters help maintain the correct tension in the engine’s timing chain system, ensuring accurate synchronization between the crankshaft and camshafts.

Fits:
Porsche 964 1989 - 1994
Porsche 964 Turbo 1993 - 1994 3.6L
Porsche 964 RS
Porsche 993 1994 - 1998

Diagram Ref no 9 and 10.

The OE Match versions correspond to Porsche reference numbers 96410507900 / 96410507901 (left side) and 96410508000 / 96410508001 (right side) and are designed as direct replacements for the original factory components.

The timing chain adjuster is part of the camshaft timing system used in air-cooled Porsche flat-six engines. The component works together with the timing chain tensioner and guide rails to keep the chain correctly tensioned as the engine operates.

Each engine uses separate left and right adjusters, depending on the cylinder bank.

The chain adjuster maintains the proper position and tension of the timing chain, preventing slack or vibration within the timing assembly. By keeping the chain properly tensioned, it helps ensure precise valve timing and smooth engine operation.

Replacing worn adjusters helps prevent timing chain noise, improves reliability and protects critical engine components from excessive wear.

Function
• Timing Chain Tension Control: Maintains proper tension in the camshaft timing chain
• Valve Timing Accuracy: Ensures correct synchronization between crankshaft and camshafts
• Engine Protection: Prevents chain slack, vibration and premature wear
• Smooth Operation: Helps eliminate chain rattle and timing instability

Timing components are constantly exposed to engine heat, oil pressure and mechanical load. Over time adjusters can wear or lose precision, leading to timing chain noise, unstable valve timing or reduced engine performance. Replacing worn chain adjusters ensures proper tensioning of the timing chain and helps protect the engine’s internal components.

Consider replacing the timing chain adjuster when:
•  Timing chain rattle or knocking noise appears
•  Performing timing chain or tensioner replacement
•  During engine rebuild or top-end service
•  High-mileage engines with original timing components


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Related, superseded, cross reference or alternative numbers for comparison.

9641050

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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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Camshaft Timing Chain. CLOSED TYPE.
OE Match camshaft timing chain - the primary chain that connects the crankshaft to the camshaft(s) and synchronises their rotation. It corresponds to Porsche OEM ref 993.105.529.00, which was used in Porsche 911 1965 - 1997 models.
Fits left or right. Sold each.

Fits:
Porsche 911 1965 - 1989
Porsche 964 1991 - 1993
Porsche 993 1994 - 1997

Diagram ref no 1

The camshaft timing chain is a critical engine component that maintains precise timing between the crankshaft and camshaft(s). This timing governs when the engine’s intake and exhaust valves open and close relative to piston position - a key factor in efficient combustion, engine power, emissions, and overall drivability. The chain connects the rotating crankshaft to the camshafts so that valve timing is mechanically linked and constant.

Function:
• Synchronises engine timing: Maintains crankshaft-to-camshaft rotation alignment
• Supports combustion efficiency: Ensures accurate valve events for intake and exhaust strokes
• Transfers mechanical drive: From crankshaft to camshaft drive mechanisms
• Withstands high loads: Engine torque and RPM forces over long service life.

Unlike timing belts, timing chains are metal-to-metal and designed for durability, although they can stretch or wear with high mileage or inadequate lubrication.

The timing chain is at the heart of the engine’s mechanical timing system. While chains are generally long-lasting, wear can occur due to mileage, heat cycling, lubrication contamination, or slack from chain stretch. A worn or stretched timing chain can lead to:
•  Incorrect valve timing
•  Engine noise (rattle at startup or idle)
•  Reduced power and efficiency Irregular idle and misfires
•  Potential catastrophic engine damage if timing deviates too far.

Replacing a worn chain with an OE Match unit restores correct timing precision and helps protect major internal engine components.

When to replace. Install a new timing chain when:
•  There is timing chain noise (rattling) at startup or idle
•  Chain tensioner or guides are being replaced
•  Engine has high mileage with original timing components
•  You are performing engine rebuild, top-end service, or head removal
•  Diagnostic codes indicate timing inconsistencies

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

99310552900

The product you are viewing cross references to these numbers