Bushing – Fits Mercury/Mercruiser 18-25 HP Outboards (Replaces 23-85557)

$8.49 $13.00

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Bushing – Fits Mercury/Mercruiser 18-25 HP Outboards (Replaces 23-85557) is backordered and will ship as soon as it is back in stock.

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Product Details

This propeller shaft Bushing – Fits Mercury/Mercruiser 18-25 HP Outboards (Replaces 23-85557) and is designed for a precise fit on various Mercury/Mercruiser outboard engines from 15–25 HP (2-Stroke, 1985–2010) and specific 25 HP Force outboards (1996–1998). It is typically installed in the forward gear assembly within the gear housing.

This component serves as a direct replacement for Mercury 23-85557, Sierra 18-3075, and SEI Marine 93-262-16.

Installs in the gear housing (lower unit) to support the propeller shaft.
Engineered for use in propeller shaft gear assemblies.
Critical for maintaining alignment and reducing friction in the drivetrain.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Mercury	23-85557
Sierra	18-3075
SEI Marine	93-262-16

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury and Mariner models, this bushing fits a wide variety of 2-stroke and 4-stroke outboards, including standard, XD, Marathon, Sea Pro, and Jet drives from 1985 forward.

For Force outboards, compatibility is confirmed for 25 HP models from 1996–1998.

Sears-branded models using a remote 6.6-gallon fuel tank from 1997–1998 are also compatible.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury	18	18	2-Stroke	1985–1998	23-85557	Various serial number ranges
Mercury	18XD	18	2-Stroke	1985–2001	23-85557
Mercury	20	20	2-Stroke	1996–2010	23-85557
Mercury	20 Jet	20	2-Stroke	1996–2010	23-85557
Mercury	20XD	20	2-Stroke	1985–2001	23-85557
Mercury	25	25	2-Stroke	1985–2010	23-85557	Various serial ranges
Mercury	25XD	25	2-Stroke	1985–2001	23-85557
Mercury	25 HP Lightning	25	2-Stroke	1996–1997	23-85557	International only, 3-cylinder
Mercury	25 Marathon	25	2-Stroke	1996–2010	23-85557
Mercury	25 Sea Pro	25	2-Stroke	1996–2010	23-85557
Mercury	Super 15	15	2-Stroke	1996–2010	23-85557
Mercury	15 Marathon XD	15	2-Stroke	1996–2010	23-85557
Mercury	15 Sea Pro (XD)	15	2-Stroke	1996–2010	23-85557
Mercury	9.9	9.9	4-Stroke	1998–2010	23-85557	323cc models
Mercury	15	15	4-Stroke	1998–2010	23-85557	Various serial ranges
Mariner	13.5	13.5	4-Stroke	1998–2010	23-85557	International models
Mariner	15	15	4-Stroke	1998–2010	23-85557
Mariner	15 Bodensee	15	4-Stroke	1998–2010	23-85557
Force	25 HP	25	2-Stroke	1996	23-85557
Force	25 HP	25	2-Stroke	1997	23-85557
Force	25 HP	25	2-Stroke	1998	23-85557	Serial: 0E288000-0E344999
Sears	25 HP	25	2-Stroke	1997	23-85557	With 6.6 gallon remote tank
Sears	25 HP	25	2-Stroke	1998	23-85557	With 6.6 gallon remote tank

Technical Specs

Product Type: Propeller Shaft Bushing
Installation: Gear Housing/Lower Unit
Dimensions: Height: 2.2 in, Width: 10.0 in, Length: 8.0 in
Weight: 0.06 lbs (0.027 kg)
Application: Propeller Shaft Gear Assembly
Other Technical Attributes: Installed in forward gear assembly
GTIN: 745061199323
Manufacturer: Mercury Marine

What’s in the Box

1 x Bushing (23-85557)

Installation Notes

Ensure the engine is off and the battery is disconnected. Shift the outboard to the neutral position.
Drain the gearcase lubricant by removing the upper and lower drain/fill plugs.
Remove the propeller and associated hardware.
Unbolt and carefully separate the lower unit (gearcase) from the upper driveshaft housing.
Disassemble the gear housing to access the propeller shaft and forward gear assembly. Refer to your service manual for the specific procedure.
Remove the old bushing, taking care not to damage the housing or surrounding components.
Clean the bushing bore thoroughly to remove any old sealant, corrosion, or debris.
Press the new bushing into place using an appropriate driver or press tool. Ensure it is fully seated and properly aligned.
Reassemble the gear housing, propeller shaft, and lower unit components in reverse order.
Re-install the lower unit, refill with fresh gear lubricant, and attach the propeller.

Troubleshooting & FAQ

How do I know if my propeller shaft bushing is failing?

Common signs of a worn or failing bushing include excessive vibration, especially at speed; a "rumbling" or "grinding" noise from the lower unit; and visible metal shavings in the gear lube when drained. An inspection may also reveal excessive play in the propeller shaft.

Can I replace this bushing without special tools?

While basic hand tools are needed for disassembly, removing the old bushing and pressing in the new one often requires a specific bushing driver or a press to avoid damaging the new part or the gearcase housing. Professional installation is highly recommended.

What is the recommended replacement interval for this part?

There is no fixed replacement interval. Bushings should be inspected for wear whenever the lower unit is serviced or if symptoms of failure (like vibration or noise) appear. It's common to replace them during a more comprehensive lower unit rebuild.

Is there a break-in period after installation?

No specific break-in period is required. However, it's good practice to run the engine in the water at low to medium RPMs after installation to check for any unusual noises, vibrations, or leaks from the gearcase before resuming normal operation.

Will this bushing fit a Bigfoot/High Thrust model?

Yes, this bushing is listed as compatible with certain Mercury Bigfoot models with a 2.42:1 gear ratio. Always confirm your specific engine's serial number and part requirements with a service manual before ordering.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost?

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns?

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

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