Original BMW Timing Chain Deflection Rail for BMW E39 M5 and E52 Z8 (2000–2003)

The Original BMW timing chain deflection rail, part number 11-31-1-406-366, guides the timing chain inside the timing case of the S62 V8 in the 2000–2003 BMW M5 and Z8. BMW calls it a deflection rail, and most shops know it as a timing chain guide rail. A chain-driven timing system runs noisier than a belt, and this rail's plastic guide face keeps the chain quiet as it travels between the crankshaft and camshaft sprockets. Over time that plastic can wear down to the metal beneath it. Once it does, the timing case gets loud and the engine's timing can be thrown off. The rail weighs 565 g (1.2 lb) and is made in Germany.

Original BMW Parts carry a 24-month parts warranty.

BMW's parts data ties this number to a single engine, the S62, as fitted to the E39 M5 and the E52 Z8. Production of the part began in September 1998, and no end date is shown. The M5 and Z8 share the same number, so there is no separate roadster version. The timing chain keeps the valves opening and closing in step with the pistons. That makes the guides that hold the chain's path as much a part of the timing system as the chain itself.

Technical Details

• Manufacturer: BMW (Original BMW part)
• Part number: 11-31-1-406-366
• BMW part name: deflection rail (timing chain guide rail)
• Function: guides the timing chain in the timing case
• Engine: S62 V8
• Weight: 565 g (1.2 lb)
• Production start: September 1998
• Sold as: one piece
• Made in: Germany
• Warranty: 24-month parts warranty on Original BMW Parts

Common Questions

What does a worn S62 guide rail sound like?
The usual sign is a rattle or clatter from the engine, most noticeable at startup or idle. The noise comes from the chain striking or rubbing nearby parts once the guide is worn or broken.

Can a worn rail cause running problems?
Yes. A worn or damaged guide can let the chain slip, which throws off crankshaft-to-camshaft timing and can cause misfires. A badly worn rail can also lead to stalling or hard starting.

Do the M5 and Z8 use the same rail?
They do. BMW fits part 11-31-1-406-366 to the S62 in both the E39 M5 and the E52 Z8.

PMB supplies this rail for owners who want to keep an S62 timing system to factory specification.

Fitment & Compatibility

Use the fitment table below to confirm year, make, model, submodel, and any notes tied to your exact vehicle. Pay close attention to engine, chassis, position, and option-specific details before ordering. PMB Performance has spent over 20 years matching parts to vehicles and can verify this against your VIN.