INA US Accessory Drive Belt Tensioner Assembly FT40121
INA US Accessory Drive Belt Tensioner Assembly FT40121 - view 2
INA US Accessory Drive Belt Tensioner Assembly FT40121
INA US Accessory Drive Belt Tensioner Assembly FT40121 - view 2

Belt Tensioner for 2006-2010 BMW 550i & More - Ina US FT40121

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$91.99
MPN: FT40121
UPC: 670774252488
Item Package Quantity: 1
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INA US Accessory Drive Belt Tensioner Assembly P/N:FT40121
INA US Accessory Drive Belt Tensioner Assembly P/N:FT40121
$91.99

Keep every accessory on your BMW spinning quietly with the INA US Accessory Drive Belt Tensioner Assembly (MPN FT40121). This tensioner applies tension to the front end auxiliary drive (FEAD) belt, holding steady tension so the belt drives the engine's accessories without slipping. It fits many vehicles, among them the 2006-2010 BMW 550i, 2003-2008 BMW 760Li and 2003-2006 BMW X5 — see the Buyer's Guide tab for the full list and engine-level details.

  • Precise tension control: engineered to deliver consistent belt tension for reliable operation of the engine's accessory systems.
  • FEAD vibration damping: designed to provide vibration damping in tight installation spaces on high-load engines.
  • Maintains belt tension: helps prevent slippage and reduce premature wear to support belt and accessory life.
  • Smoother, quieter drive: minimizes vibration and noise for smoother engine operation.

Built from high-quality materials for long-lasting reliability, even under demanding conditions. If a worn or seized tensioner is behind belt squeal, chirping, or excess vibration, installing this assembly replaces that component.

Interchange: 11 28 7 505 566 · 11 28 7 549 589 · 7 505 566 · 7 549 589 · 10-0716
11287505566 · 11287549589 · 7505566 · 7549589 · 100716 · APV2304 · 55048 · 5340121100

This part cross-references / interchanges with the following part numbers:

11 28 7 505 566, 11 28 7 549 589, 7 505 566, 7 549 589, APV2304, 55048, 5340121100, 10-0716

Frequently Asked Questions

What does this belt tensioner do?

It applies tension to the accessory drive (FEAD) belt, keeping it tight so it can drive engine accessories without slipping.

Will this fit my BMW?

It fits many BMW models, among them the 2006-2010 BMW 550i, 2003-2008 BMW 760Li and 2003-2006 BMW X5. Check the Buyer's Guide tab for the full list.

What are signs my tensioner may need replacing?

Belt squeal or chirping, excess vibration or noise, and a belt that slips or wears prematurely can be signs. Diagnose the cause before replacing.

Is this the same as a serpentine belt tensioner?

Yes. This FEAD tensioner maintains tension on the front end auxiliary drive belt.

Should I replace the belt too?

Inspecting the drive belt while the tensioner is off is good practice; replace the belt as directed by the vehicle service procedure if it shows wear.

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