N-902-818-02 Genuine VW/Audi AWD Differential Drain and Fill Plug

Genuine VW/Audi AWD differential drain and fill plug, part number N-902-818-02. This original threaded service plug closes the assigned opening in the differential arrangement below. It is supplied individually for fluid service or replacement of damaged service hardware.

Technical details

• Original number: N-902-818-02 / N90281802.
• Published nominal size: M10 x 1 x 10.
• Internal hex drive with the pictured sealing-ring arrangement beneath the head.
• Specified application: assigned service plug in the rear torque-vectoring differential arrangement.
• One plug supplied. Fluid, additional plugs, tools and differential components are separate.

The plug closes a service opening while allowing access for the applicable fluid maintenance procedure. Correct thread size, engagement and sealing hardware are necessary for a sound connection. The housing can have several service points and fluid chambers, so match the original number at the actual opening.

This is a small service plug rather than a mounting bolt or complete differential service kit. Similar-looking drain and fill plugs may differ in thread pitch, length, sealing arrangement and intended location. Vehicle model alone does not identify every plug in an AWD drivetrain.

Common reasons to replace

Replace a rounded internal hex drive, damaged threads, deformation, corrosion affecting reliable installation or missing service hardware. A plug previously tightened with an incorrect tool may no longer provide a reliable connection during the next fluid service.

Renew the plug or sealing hardware whenever the factory procedure requires replacement. Leakage around the service opening should be traced to its source: inspect the plug, sealing contact surface and housing threads rather than assuming the plug is the only possible cause.

An unsuitable replacement plug or damaged sealing ring can prevent correct seating. A new plug cannot repair stripped housing threads, a cracked casing, worn differential components or a leak from a nearby shaft seal. Correct the diagnosed defect before completing fluid service.

Installation and service notes

Follow the factory procedure for the exact differential and fluid chamber. Identify the prescribed fill and drain locations before removing a plug. Keep service tools and the area around the opening clean so debris is not introduced into the assembly.

Where the procedure requires it, confirm access to the correct fill opening before draining fluid. Observe the specified vehicle position, fluid temperature, fill quantity and level-setting procedure for the actual chamber being serviced.

Inspect the housing threads and sealing surface, then fit the specified plug and sealing hardware. Start the plug by hand without cross-threading. Use a correctly sized internal hex tool fully seated in the drive.

Apply the factory tightening requirement for this exact service opening. Do not transfer a torque from an engine oil drain plug, another differential chamber or an unrelated M10 fastener. Follow the prescribed thread preparation and do not add sealant or other material unless required by the procedure.

Use the specified fluid for the actual chamber; neighboring AWD components can have different fluid requirements. This plug does not establish fluid type, level or service interval. Select fluid and other maintenance parts separately for the vehicle's original drivetrain arrangement.

After servicing, clean the surrounding area and complete the required leakage and operating checks. If the plug fails to seat normally, inspect hardware selection and the housing before tightening further. This listing supplies one original plug; order the quantity required by the service procedure.

Fitment

Confirm original N90281802 at the actual service opening before ordering. One plug supplied.