PRODUCT DETAILS
Genuine Honda Crank Pulley (13810-R40-A01) - K24Z2, K24Z3 & K24Z7
The crank pulley does more than drive your accessories. It's a harmonic damper, which means it's absorbing the torsional vibration the crankshaft produces on every combustion event. When the rubber bonding inside it degrades, it stops damping, and those vibrations go somewhere less forgiving. This is the genuine Honda replacement, 6-5/8 inches in diameter.
Grab A New Woodruff Key Too
Worth adding to your order, since it's the small part that makes this job go properly.
The crank pulley key, part number 90704-PNA-000, is what indexes the pulley to the crankshaft. It's inexpensive, it's easy to damage on removal, and a worn or nicked key means a pulley that doesn't seat exactly right.
Given that you're already in there and the part costs almost nothing, there's no sensible reason to reuse the old one.
What A Failing Pulley Looks Like
These fail in a specific and recognizable way.
The pulley is built in two pieces, an inner hub and an outer ring, bonded with rubber between them. That rubber is what absorbs vibration, and over time and heat cycles it degrades.
What you see is the outer ring separating or walking relative to the inner hub. Sometimes there's visible rubber cracking or missing chunks. Sometimes the outer ring has shifted enough that your belt no longer tracks straight, which shows up as belt wear or squealing.
The serious version is the outer ring letting go entirely at speed, which takes your accessory belt with it and can do real damage on the way out.
Why Damping Matters Beyond The Noise
Worth understanding, because it's easy to think of this as just a pulley.
A crankshaft doesn't rotate smoothly. Every combustion event twists it, and it springs back, which sets up torsional vibration along its length. Left unchecked, that vibration is genuinely destructive to the crank, the bearings, and anything driven off the front of the engine.
The damper absorbs it. When it stops working, those vibrations don't go away, they just have nowhere useful to go. That's why a degraded pulley isn't only a belt problem.
Use The Genuine Part
The damping characteristics are the specification here, and they're tuned to the engine. A pulley that bolts on and spins isn't necessarily damping the frequencies a K24 produces.
Underdrive and lightweight pulleys exist and have their place on a race engine, but they're a different product with different tradeoffs. If you want a factory-behaving engine with proper damping, this is the part.
Fitment
2013-2015 Acura ILX
2009-2014 Acura TSX
2008-2012 Honda Accord
2012-2015 Honda Civic Si
2010-2012 Honda CR-V
Covers the K24Z2, K24Z3, and K24Z7. Part number 13810-R40-A01, which supersedes 13810-R40-A02.
Who Should Grab One
This is for the K24 owner who's found a separating pulley, a belt that won't track straight, or vibration that wasn't there before. It's also worth doing on a high mileage engine you're going through, since the rubber degrades on a calendar as much as on an odometer. Add the woodruff key, torque it properly, and get the front of the engine back to doing its job.
Fits: Honda K24Z2, K24Z3, and K24Z7, see the application list above. Part number: 13810-R40-A01 (supersedes 13810-R40-A02). Diameter: 6-5/8" (16.83 cm). Type: genuine Honda crank pulley and harmonic damper. Recommended: new crank pulley key, part 90704-PNA-000.
2013-2015 Acura ILX
2009-2014 Acura TSX
2008-2012 Honda Accord
2012-2015 Honda Civic Si
2010-2012 Honda CR-V