Honda Fit/EP3/RSX Lower Ball Joint Castle Nut 90363-S47-000

Honda Lower Ball Joint Castle Nut - 90363-S47-000

Replacing your lower ball joints and you need a fresh castle nut? The 90363-S47-000 is the OEM 12mm castle nut that threads onto your lower ball joint stud. It's the nut that holds your lower ball joint to your knuckle. When you're doing suspension work and you're replacing ball joints, control arms, or knuckles, you're supposed to use a new castle nut. Old castle nuts get deformed from being torqued down and they don't seat properly when you reuse them.

Here's Why You Need a New Nut

Castle nuts are one-time use hardware. When you torque them down the first time, the threads deform slightly and the nut seats into the ball joint stud. If you reuse the old nut, it won't torque to spec properly and your ball joint can work loose. That's a safety issue. Your ball joint separates from your knuckle while you're driving and you lose steering control. Don't cheap out on a $3 nut. Replace it every time you're working on your ball joints.

Removal Trick: Flip It Upside Down for Stuck Ball Joints

Here's a trick if you're trying to remove a stuck lower ball joint and you don't have a ball joint separator tool. Thread the castle nut back onto the ball joint stud upside down so it's flush with the top of the stud. Now you've got way more surface area to hammer on without damaging the threads. Smack the nut with a hammer while prying down on the control arm. The shock from the hammer hits breaks the taper loose and the ball joint pops out of the knuckle. Way easier than trying to hammer on the stud threads or the knuckle. Just don't reuse that nut after you've been beating on it.

Sold Individually, No Cotter Pin Included

This nut's sold individually. If you're doing both sides, order two. The nut doesn't come with a cotter pin. You need to order cotter pins separately. Honda uses a specific size cotter pin for the ball joint castle nut slots. Make sure you've got the right size pin before you button everything up.

What You Get

• Honda OEM lower ball joint castle nut (part number 90363-S47-000)
• 12mm castle nut
• Threads onto lower ball joint stud
• Secures ball joint to steering knuckle
• Same nut your car came with from the factory
• Sold individually (cotter pin not included)

Fits Your Car

• 2013-2015 Acura ILX
• 2002-2004 Acura RSX
• 2001-2005 Honda Civic DX/EX/LX
• 2002-2005 Honda Civic Si
• 2012-2015 Honda Civic DX/EX/LX
• 2017-2021 Honda Civic EX/LX
• 2002-2006 Honda CR-V
• 2003-2011 Honda Element
• 2007-2020 Honda Fit
• 1999-2004 Honda Odyssey