The Mercury Genuine OEM Crankshaft Retaining Ring, Part Number 53-67446, is a small but critical component used in the crankshaft assembly of Mercury's legendary V6 two-stroke outboards.
Installed in the crankshaft bearing carrier, this precision split ring secures the lower crankshaft ball bearing in its machined bore, preventing bearing movement while maintaining proper crankshaft alignment during engine operation.
Mercury identifies Part 53-67446 as the ball bearing retaining snap ring used in the crankshaft, piston, and connecting rod assembly on numerous V6 engines.
Although inexpensive, this retaining ring performs an essential function. If the bearing is not positively retained, crankshaft end play and bearing movement can occur, potentially leading to premature bearing wear, crankshaft damage, seal failure, or catastrophic engine damage.
Fits Mercury's Legendary V6 Two-Stroke Engines
Mercury Part 53-67446 fits a remarkably wide range of legacy Mercury V6 outboards spanning more than three decades of production. It is found in many 2.0L, 2.4L, 2.5L, 3.0L, and 3.2L engines used in recreational, commercial, racing, and SportJet applications. Mercury parts catalogs list this retaining split ring across approximately 179 different engine models.
Common applications include Mercury 135 HP, 150 HP, 175 HP, 200 HP, 225 HP, 250 HP, and 300 HP V6 outboards equipped with carbureted, EFI, Laser EFI, XRI, DFI Optimax, Pro Max, Super Mag, Pro XS, Sport XS, 250XB, 300X, 300XS, SeaPro, Marathon, Offshore, SST-120, SST-140, S2000, S3000, Formula Race, and commercial powerheads.
The same retaining ring is also used in numerous SportJet 175XR2, 200 EFI, 210 Carb, 240 EFI, 240 EFI M2, 250 EFI, 250 DFI, and 250 DFI M2 engines, making it one of the most widely used crankshaft retaining components in Mercury's legacy two-stroke lineup.
Because Mercury introduced numerous engineering revisions throughout production, always verify fitment by engine serial number before ordering.
Why Replace the Retaining Ring?
Whenever the crankshaft, lower main bearing, or bearing carrier is removed during a powerhead rebuild, the retaining ring should be carefully inspected for distortion, corrosion, or loss of spring tension.
Snap rings and retaining rings are designed to maintain constant pressure within their grooves. Reusing a ring that has been stretched, damaged, or improperly removed can reduce its holding ability.
Replacing the retaining snap ring during a complete rebuild is inexpensive insurance compared to the cost of repairing a damaged crankshaft or crankcase.
Recommended During Engine Rebuilds
The Mercury 53-67446 retaining ring should be considered whenever performing a complete powerhead overhaul, including crankshaft replacement, lower main bearing replacement, connecting rod service, piston replacement, sleeve installation, crankcase machining, or complete engine rebuilding.
Professional engine builders routinely replace inexpensive retaining hardware during major service because these components experience repeated stress throughout the engine's life.
Installation Tips
Before installing the new retaining ring, thoroughly clean the retaining groove and inspect it for burrs, corrosion, or damage. Verify that the lower crankshaft bearing is fully seated before installing the ring.
Use proper snap-ring pliers designed for internal retaining rings to avoid overstretching the ring during installation. After installation, confirm that the retaining ring is fully seated around the entire groove before completing engine assembly. Never force a distorted retaining ring into place or reuse one that has lost its spring tension.
Buckshot Racing #77 Tech Tip
Many builders focus on pistons, bearings, and crankshafts while overlooking small hardware that keeps those components properly located. The Mercury 53-67446 crankshaft retaining ring is one of those inexpensive parts that performs a critical job.
Replacing it during every major rebuild helps ensure proper crankshaft bearing retention and contributes to the long-term reliability of high-performance Mercury V6 engines.
Final Thoughts
The Mercury Genuine OEM Crankshaft Retaining Ring 53-67446 is an essential component for maintaining proper crankshaft bearing retention in Mercury's legendary V6 two-stroke engines.
Whether you're rebuilding a 2.0L, 2.4L, 2.5L, 3.0L, or 3.2L powerhead, servicing a 300XS, 300X, 250 Pro XS, 225 Pro Max, 200 EFI, SportJet, or SeaPro, replacing this precision retaining ring helps ensure the crankshaft and lower main bearing remain securely positioned for years of dependable service.