BMW Single VANOS High-Performance Bearing Rattle Repair Kit

Eliminate the infamous BMW Single VANOS rattle with our High-Performance Single VANOS Bearing Rattle Repair Kit, engineered specifically for BMW Single VANOS units.

As BMW Single VANOS units accumulate mileage, wear within the piston bearing assembly can create excessive axial play. The result is the familiar metallic VANOS rattle coming from the front of the engine, often described as marbles or rocks rattling around inside the timing system.

Our bearing kit replaces the worn factory bearing components with a high-performance roller bearing assembly designed to reduce unwanted movement, eliminate VANOS bearing rattle, and restore proper operation of the VANOS piston assembly.

This kit is designed for Single VANOS units found on BMW M50TU, M52, S50, and S52 engines. (Does not fit European S50B32 engines)

Kit Includes

• 1 VANOS Bearing Ring
• 2 High-Performance Roller Bearings

Individually Fitment Checked

Bearing fit is extremely important when rebuilding a VANOS unit.

Every bearing kit is checked for proper fit using a brand-new VANOS unit before it leaves us. This gives us a known factory-spec reference point for the bearing assembly.

However, your VANOS unit may have accumulated decades of wear. Because of variations in wear between individual units, minor adjustment of the bearing ring or race may be required to achieve the correct fit and preload in your specific VANOS assembly.

This is normal and allows the bearing assembly to be precisely fitted to your VANOS rather than relying on a one-size-fits-all tolerance.

What Does VANOS Bearing Rattle Sound Like?

A worn Single VANOS bearing assembly typically creates a metallic rattling or buzzing noise from the front of the engine. Many owners describe it as sounding like a handful of marbles or small rocks being shaken around inside the VANOS unit.

The noise may be especially noticeable at certain engine speeds and can easily be mistaken for timing chain or timing system noise.

Replacing the worn bearing components and properly setting the bearing preload helps eliminate this excessive movement and restore proper VANOS operation.

Don't Be Fooled by Cheap VANOS Bearing Kits

Not all VANOS rebuild components are created equal.

There are cheaper bearing kits available online, but bearing quality, tolerances, and fitment matter. There's a reason some kits cost significantly less.

Our high-performance roller bearing components are specifically selected for the BMW Single VANOS application, and every kit is checked in a brand-new VANOS unit for proper reference fitment before being sold.

When you're taking apart your VANOS unit, saving a few dollars on one of the most important components inside it isn't worth doing the job twice.

Bearing Fitment & Adjustment

Important: Because used VANOS units can have different amounts of wear, some bearing assemblies may require minor adjustment during installation.

400-grit sandpaper must be used for the following adjustment procedures.

To Tighten the Bearing

If axial play is present or there is insufficient preload, the bearing ring can be carefully sanded to tighten the assembly.

1. Place a sheet of 400-grit sandpaper on a solid, completely flat surface.
2. Using medium pressure, sand one surface of the bearing ring back and forth approximately 6–8 inches, 30–40 times.
3. Rotate the ring 90 degrees and repeat the sanding procedure.
4. Flip the ring over and repeat the procedure on the opposite surface.
5. Rotate the ring another 90 degrees and repeat.

This procedure removes only a very small amount of material—approximately 0.004–0.006 mm from the total thickness of the ring.

Reassemble and check bearing fit and preload. Repeat only if additional adjustment is necessary.

To Loosen the Bearing

If excessive force is required to rotate the VANOS piston, the bearing race can be carefully sanded to increase clearance.

1. Place a sheet of 400-grit sandpaper on a solid, completely flat surface.
2. Using medium pressure, sand one surface of the bearing race back and forth approximately 6–8 inches, 30–40 times.
3. Rotate the race 90 degrees and repeat the sanding procedure.
4. Flip the race over and repeat the procedure on the opposite surface.
5. Rotate the race another 90 degrees and repeat.

This procedure removes approximately 0.004–0.006 mm from the total thickness of the race.

Reassemble and check the piston for proper movement. Repeat only if additional adjustment is required.

Always remove material gradually. It is much easier to remove additional material than to correct a component that has been sanded too far.

Fitment Guide

This bearing kit is designed for applicable BMW Single VANOS units used with the M50TU, M52, S50, and S52 engine families.

Important S50 Fitment Information

US-spec S50B30US: The 1995 US-market E36 M3 uses a Single VANOS S50B30US engine and is an applicable Single VANOS application.

European S50B30: Not Applicable.

European S50B32: Not Applicable

Important Production-Date Note

BMW changed several models from M52 Single VANOS to M52TU Dual VANOS around the 1998–1999 production period. Model year alone is not always sufficient to determine which VANOS system is installed.

For vehicles produced around this transition, verify the engine code and VANOS configuration before ordering.

Fix the Rattle at the Source

If your BMW's Single VANOS sounds like a box of marbles, don't just live with the noise. Our high-performance bearing kit addresses the excessive play within the VANOS bearing assembly and gives you the components needed to precisely fit the bearing to your individual VANOS unit.

Whether you're repairing an existing VANOS rattle or performing a comprehensive VANOS rebuild, this is an ideal upgrade while the unit is already apart.