Original BMW VANOS Diaphragm Spring for BMW 3 Series, 5 Series, M3, and Z3 (1992–2000)

Original BMW diaphragm spring 11-36-1-403-550 belongs to the single VANOS unit on the M50, M52, S50, and S52 inline sixes, where BMW uses it on engines that run two thrust washers on the intake side; it fits the BMW 3 Series, 5 Series, M3, and Z3 from 1992 to 2000. BMW's name for the part is diaphragm spring, which says more than the generic spring plate description it often carries. It weighs 24 grams. BMW's production for this number started in March 1994, and it remains available. It is made in Germany. A diaphragm spring is a dished spring washer that holds a steady axial preload on the parts stacked against it in a small space.

Original BMW Parts carry a 24-month parts warranty.

Choosing the right spring comes down to the VANOS layout. This one is for single VANOS engines with the two-thrust-washer arrangement on the intake side, so confirm that setup before ordering. BMW applies it to the E36 3 Series and M3, the E34 and E39 5 Series, and the Z3, all with the M50, M52, S50, or S52 engine. BMW shows no earlier or replacement number for it. It is sold by the piece.

Technical Details

• Manufacturer: BMW (Original BMW Parts)
• Part number: 11-36-1-403-550
• BMW part name: Diaphragm spring
• System: single VANOS, intake side, with two thrust washers
• Weight: 24 g (0.85 oz)
• Production start: March 1994, still in production
• Country of manufacture: Germany
• Sold individually, by the piece
• Warranty: 24 months

Common Questions

Is this the same as a VANOS spring plate?
BMW calls this part a diaphragm spring. It is the spring used in the single VANOS unit on engines with two intake-side thrust washers.

Which engines does it fit?
BMW fits it to the M50, M52, S50, and S52 inline sixes in the models shown above.

Where is it made?
It is a genuine BMW part made in Germany.

Fitment & Compatibility

Compare your production year and trim against the table below. PMB Performance has spent over 20 years matching parts to vehicles and can verify this against your VIN.