PRODUCT DETAILS
Genuine Honda Crank Pulley Woodruff Key (90704-634-000) - B & D Series
This is the woodruff key that indexes your crank pulley to the crankshaft. It's small, it costs almost nothing, and it's the difference between a pulley that stays where you put it and one that spins on the crank. Anyone who's dealt with a wallowed keyway knows what that costs, and this is the part that prevents it.
Replace It With Your Timing Belt
The practical advice on this page, and the reason most people are here.
You can't reach the timing belt without pulling the crank pulley, which means the key comes out too. It's a small piece of hardened steel being pried from a tight slot, and it's easy to nick or bend on removal even when you're careful.
A worn or damaged key means a pulley that doesn't seat exactly right, which allows movement under load. That movement eventually wallows out the keyway in the crankshaft itself, and repairing that is an engine-out job on a part you can't replace separately.
Since you're already in there doing a timing belt, and this costs a fraction of anything else in the job, there's no version of reusing the old key that makes sense.
What A Spun Pulley Looks Like
Worth recognizing, because the symptoms point elsewhere at first.
A pulley that's moved on the crank throws off your timing marks. You'll set the engine to TDC by the pulley and find the cam marks don't line up, or you'll chase a timing problem that doesn't respond to adjustment because the reference itself has moved.
On a D-series that's now thirty years old, a previous owner's careless pulley install is a genuine possibility. If your timing marks don't agree with each other, the keyway is worth a look before you go further.
Get The Torque Right
The key indexes the pulley, but the crank bolt is what holds everything together.
Look up the torque spec for your engine and follow it. These bolts are torqued high for a reason, and an undertorqued bolt lets the pulley work against the key, which puts you right back where you started with a damaged keyway.
Clean the keyway and slot before assembly so nothing holds the pulley off its seat.
Use The Genuine Part
The dimensions are the entire specification. A key that's slightly undersized allows movement, and one that's oversized won't seat properly. Either outcome defeats the purpose.
Honda makes these to tight tolerances in hardened steel that resists the deformation your old one has already started showing. On a part this cheap protecting a crankshaft, it's an easy decision.
Fitment
1976-1989 Honda Accord
1973-2005 Honda Civic
1984-1991 Honda CRX
1993-1997 Honda Del Sol
1997-2001 Honda CR-V
1979-1991 Honda Prelude
1986-2001 Acura Integra
Covers B-series and D-series engines. Part number 90704-634-000.
Who Should Grab One
This is for anyone doing a timing belt, replacing a crank pulley, or building an engine who'd rather fit a fresh key than trust one with three decades of shear cycles behind it. It's the cheapest part in the job and among the most consequential if it fails. Add it to the order and torque the bolt properly.
Fits: Honda and Acura B-series and D-series, see the application list above. Part number: 90704-634-000. Type: genuine Honda crank pulley woodruff key. Recommended: replace whenever the crank pulley is removed.