Lower Unit Seal Kit – Fits Suzuki DT75/DT85 2-Stroke Outboards (Replaces 25700-95500/25700-95501)

$29.95

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Product Details

This Lower Unit Seal Kit – Fits Suzuki DT75/DT85 2-Stroke Outboards contains the necessary components to overhaul the gear case on Suzuki DT75 and DT85 2-stroke outboard engines from 1988 to 2000. It is designed to restore sealing integrity and prevent water intrusion.

This kit serves as a direct replacement for Suzuki OEM parts 25700-95500 and 25700-95501, as well as Sierra aftermarket part 18-8340.

Installation Location: Lower Unit / Gear Case
Includes OEM-quality seals and gaskets for a reliable fit.

Part Number Matrix

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

Brand	Part Number	Superseded By	Notes
Suzuki	25700-95500	25700-95501	Original OEM part
Suzuki	25700-95501		Current OEM part
Sierra	18-8340		Aftermarket Replacement

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Suzuki owners: This kit is confirmed to fit the DT75 and DT85 2-stroke models listed below from years 1988 through 2000. Please verify your specific model code before ordering.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Suzuki	DT75TCLJ	75	2-Stroke	1988	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLJ	85	2-Stroke	1988	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLK	75	2-Stroke	1989	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLK	85	2-Stroke	1989	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLL	75	2-Stroke	1990	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLL	85	2-Stroke	1990	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLM	75	2-Stroke	1991	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLM	85	2-Stroke	1991	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLN	75	2-Stroke	1992	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLN	85	2-Stroke	1992	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLP	75	2-Stroke	1993	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLP	85	2-Stroke	1993	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLR	75	2-Stroke	1994	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLR	85	2-Stroke	1994	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLS	75	2-Stroke	1995	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLS	85	2-Stroke	1995	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLT	75	2-Stroke	1996	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLT	85	2-Stroke	1996	25700-95501	Supersedes 25700-95500
Suzuki	DT75TCLV	75	2-Stroke	1997	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLV	85	2-Stroke	1997	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLW	85	2-Stroke	1998	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLX	85	2-Stroke	1999	25700-95501	Supersedes 25700-95500
Suzuki	DT85TCLY	85	2-Stroke	2000	25700-95501	Supersedes 25700-95500

Technical Specs

Product Type: Lower Unit Seal Kit
Installation: Gear Case
Other Technical Attributes: OEM-quality seals and gaskets
Product Dimensions: Height: 7.13 in; Width: 6.0 in; Length: 0.88 in

What’s in the Box

1 x Seal Kit Components (Replaces 25700-95501)

Installation Notes

Disconnect the engine's battery and remove the propeller.
Position a drain pan under the lower unit and remove the drain/fill screws to empty the gear lubricant.
Remove the bolts securing the lower unit to the engine's midsection and carefully lower it.
Disassemble the gear case, including the propeller shaft housing and water pump, noting the orientation of each part.
Carefully extract all old seals, o-rings, and gaskets using appropriate seal pullers. Avoid scratching metal surfaces.
Thoroughly clean all sealing surfaces of debris and old sealant.
Lightly coat the new seals with marine grease and press them into place until fully seated.
Reassemble all components in reverse order, ensuring correct alignment.
Torque all bolts and screws to the manufacturer's specified values.
Refill the gear case with fresh marine gear lubricant until it flows from the upper vent hole, then reinstall both screws.
Check for any leaks before operating the engine.

Troubleshooting & FAQ

How do I identify a failing lower unit seal?

The most common sign is milky, grey, or chunky gear lubricant, which indicates water contamination. You may also see visible oil leaking from behind the propeller or from the weep hole under the water pump housing.

Will this kit fit a 4-stroke Suzuki model?

No, this seal kit is exclusively for the Suzuki DT75 and DT85 2-stroke outboard models manufactured between 1988 and 2000. It is not compatible with any 4-stroke engines.

My original part number is 25700-95500. Is this the correct kit?

Yes. Suzuki superseded part number 25700-95500 with 25700-95501. This aftermarket kit is designed to replace both of those OEM part numbers.

How often should lower unit seals be replaced?

As a preventative measure, seals should be inspected annually and replaced every 2-3 years, or if you discover water in the gear lube. Immediate replacement is necessary if you get fishing line wrapped around the prop shaft, as this can quickly destroy the seal.

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.

About Sea Sierra

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Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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