SKU: 61093860077

Lower Unit Seal Kit – Fits Johnson/Evinrude 18-25 HP (Replaces 18-2684, 87606, 9-74105)

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Description

Lower Unit Seal Kit – Fits Johnson/Evinrude 18-25 HP (Replaces 18-2684, 87606, 9-74105)Lower Unit Seal Kit Fits Johnson Evinrude 18 25 HP (Replaces 18 2684, 87606, 9 74105) This lower unit seal kit is designed for Johnson Evinrude 18 HP, 20 HP, and 25 HP 2 stroke outboard motors manufactured between 1958 and 1978. It provides all the necessary seals and gaskets to rebuild and reseal your lower unit gearcase, preventing water intrusion and oil leaks. This kit serves as a direct replacement for several aftermarket part numbers, including

Lower Unit Seal Kit – Fits Johnson/Evinrude 18-25 HP (Replaces 18-2684, 87606, 9-74105)

This lower unit seal kit is designed for Johnson/Evinrude 18 HP, 20 HP, and 25 HP 2-stroke outboard motors manufactured between 1958 and 1978. It provides all the necessary seals and gaskets to rebuild and reseal your lower unit gearcase, preventing water intrusion and oil leaks.

This kit serves as a direct replacement for several aftermarket part numbers, including Sierra 18-2684, GLM 87606, Mallory 9-74105, QuickMarine 18-2684, JSProxam 18-2684, Boatpartstore 18-2684, and EMP/Wholesale Marine 26-01728.

  • Installation Type: Complete repair and replacement of lower unit seals.
  • Function: Restores gearcase integrity by replacing all critical seals and gaskets.
  • Warranty: This kit is backed by a 90-day warranty (JSProxam).

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Brand Part Number
Sierra 18-2684
GLM 87606
Mallory 9-74105
QuickMarine 18-2684
JSProxam 18-2684
Boatpartstore 18-2684
EMP/Wholesale Marine 26-01728

Compatible Engine Models

Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson/Evinrude Serial Number Guide.

Brand Model Rated HP Stroke Years Notes
Johnson/Evinrude All 18 2-Stroke 1958-1973 2 cylinders
Johnson/Evinrude All 20 2-Stroke 1966-1973 2 cylinders
Johnson/Evinrude All 25 2-Stroke 1969-1978 2 cylinders

Technical Specifications

Specification Value
Product Type Lower Unit/Gearcase Seal Kit
Installation Repair/Replace
Package Includes Complete seals/gaskets for lower unit
Warranty 90 Day (JSProxam)

Package Contents

  • 1 x Shift Rod Gasket (18-0882)
  • 1 x Oil Seal (18-2031)
  • 1 x Oil Seal (18-2032)
  • 1 x Seal Kits (18-2534)
  • 2 x Drain/Fill Plug Washer (18-4248)
  • 1 x O-Ring (18-7100)
  • 1 x O-Ring (18-7120)

Installation Guide

  1. Preparation: Drain the gearcase lubricant completely. Secure the outboard motor in a stable, upright position.
  2. Lower Unit Removal: Unbolt and carefully detach the lower unit (gearcase) from the engine's midsection. You may need to disconnect the shift linkage.
  3. Bearing Carrier Disassembly: Remove the propeller shaft bearing carrier. This often requires a special puller tool.
  4. Old Seal Removal: Identify and carefully pry out the old oil seals, gaskets, and O-rings from the housing and driveshaft areas. Avoid scratching the metal surfaces.
  5. Cleaning and Inspection: Thoroughly clean all sealing surfaces, removing any old adhesive, corrosion, or debris. Inspect components for excessive wear or damage.
  6. New Seal Installation: Lubricate the new seals and O-rings with marine grease. Press them into place evenly, ensuring they are fully seated and square in their bores.
  7. Reassembly: Reassemble the components in the reverse order of disassembly. Ensure correct alignment of all parts.
  8. Lower Unit Reinstallation: Reattach the lower unit to the motor, making sure the driveshaft spline, water tube, and shift rod are correctly aligned.
  9. Refill with Lubricant: Fill the gearcase with the manufacturer-recommended lower unit lubricant through the bottom fill hole until it flows out the upper vent hole.
  10. Leak Check: Install both drain/vent plug screws with new washers. Check for any signs of leakage around the seals before operating the engine.

Troubleshooting & FAQ

Q: How can I be sure this seal kit fits my specific Johnson/Evinrude motor?
A: This kit is designed for the 18, 20, and 25 HP models listed in the compatibility table for years 1958-1978. Always verify your engine's horsepower and year range before ordering. You can also use the cross-reference table to match your existing part number if you are replacing another aftermarket kit.

Q: What are common signs that my lower unit seals are failing?
A: The most common indicator is milky or creamy-looking gear lube when you drain it, which signals water intrusion. Other signs include visible oil leaks around the propeller shaft or driveshaft, or a recurring need to top off the gear oil.

Q: How often should lower unit seals be replaced?
A: We recommend replacing lower unit seals as part of regular preventative maintenance every 2-3 seasons or 200-300 hours of use. You should replace them immediately if you discover any signs of water intrusion or oil leakage.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

  • Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
  • This product is an aftermarket replacement part and is not an OEM component.
  • Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

  • Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
  • Fast Global Shipping: Free delivery worldwide in 5–15 days.
  • Direct from Manufacturer: Competitive pricing without compromising quality.
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 61093860077

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4.1 ★★★★★
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Product Reviews
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Poorboy5764
West Palm Beach, US
★★★★★ 5
Great Timex Watch
Color: Black/Yellow
This Timex Ironman watch arrived on time and is of great quality. I have used these watches for years and have NO complaints about their longevity, accuracy, or dependability. I will definitely purchase again if needed.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 1, 2026
R
Verified Purchase
Rikeshay
Massapequa, US
★★★★★ 5
Item as described.
Color: Dark Blue
A timeless tradition of a great design and useful watch. Have been using this watch design for over a 30 years.
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Reviewed in the United States on May 27, 2026
B
Verified Purchase
Buck
Boise, US
★★★★★ 5
Great thowback to the OG Ironman, but Amazon's listing gets it undue negativity.
Color: Black/Yellow
Amazon's listing is not very good with it's wording so this watch has gotten undue negative reviews. I've seen this model listed as both the Endure 30 and the Original 30 Shock, it has 1 alarm with 3 different modes (not 3 separate alarms), 200m WR, ISO shock resistance, (reverse) Indiglo with night mode, 2 time zones, 12/24hr time, 30 lap stopwatch, 24hr countdown timer (repeatable), and day/date (MM.DD or DD.MM). Its basically a slightly updated feature set compared to an Ironman 8-lap. This watch is great, it's got the look of the original Ironman 8-lap with modern guts. The only minus for me is it could be a little slimmer on the wrist, but I also didn't realize it was shock resistant when I bought it. For comparison, it is a few mm smaller in all dimensions than a G-Shock G2300/G2310/GW2310 series. The band is similar to G-Shocks in that it is formed/molded around the wrist but like the case it's still slimmer in the way it wears around the wrist. Not as slim as an F91W but not as massive as any G-Shock basically. The module has a better display with bigger numbers than the above mentioned Casios. With the exception of the lap memory, the G23## G-Shocks have more features, but the Endure 30 is much easier to use thanks to the display and larger buttons. If you want 3 alarms you need the very similar Classic 30. The main differences being the Classic has 3 separate alarms (not 1), occasion reminders and 3 time zones but losses the Ironman 8-lap look, the shock resistance and it's only 100m WR. The Classic seems to come in at least two case varieties (chunky or slim), two sizes and many color combinations. If you only need the Endure 30's features but want a different shape/size/style/slimmness, I believe the Essential 10/30 and BASIC Transit models are functionally the same with only different lap memories, WR, and no shock resistance. Unfortunately, Timex doesn't easily identify the actual module used in a watch like Casio, so the best way to figure out what features a watch has is to lookup the watch model on the Timex website. Of course the manuals do not always match the marketing names they have used over the years (Endure/Classic/Essential/etc), and each manual covers a few shapes/sizes of watch but just search for the model number in the manuals sections and you'll eventually find the right one. If no manual pops up right away delete digits from the right end of the model number until a manual is found, I believe those last digits only indicate slight variances in style/color that are not important to functionality.
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Reviewed in the United States on May 31, 2021
H
Verified Purchase
Hudson
Belleville, US
★★★★★ 1
Good interface but unwearable watch band
Color: Black
This review will be divided into 3 sections: looks, usability, and comfort. LOOKS I guess there's not much to say as style is very individual. I think this watch looks good for what you pay for it. USABILITY What I liked about this watch is that I could use it right out of the box. I have had basic Timex digital watches before (never this exact interface), and I was able to quickly figure it out. A quick glance at the manual to make sure I wasn't unaware of any features and I had 100% grasp of all the watch's features. The Timex interface puts many others to shame with its user-friendliness. On this model Timex has added a 'guide' on the display that tells you which button will do what-- increase number, decrease number, etc. This is cool. If you're even remotely handy with interfaces, once you learn this one, you'll know it backwards and forwards, and even if you forget, there's the in-display guide. The functions are standard for a Timex digital-- time and date, stopwatch with lap timing, countdown timer, and alarm. There is a 2nd time zone but no dedicated mode for it. You access it by holding the 'start' button when in the time mode. I like this feature as I occasionally need to know when to call people in 1 particular time zone. But, for example, if you are often switching back and forth between 2 time zones, you will have to reset the time to have the watch display the correct time at all times. And if you need more than 2 time zones, sorry, out of luck. Stopwatch (chrono) is good. Don't use the lap counter much but it seems to work well. Some have complained that the 'start' and 'stop' should be on the same button. Overall, it is a very uncluttered and usable interface. At first I thought it was very inaccurate at timekeeping, but it must have gotten accidentally reset because over the few months since I set it, it's only a couple seconds off from time.gov. very good timekeeping. It seems very water resistant. I have taken it swimming, surfing, and it held up fine. I haven't thoroughly tested its shock resistance but it has done some hiking and climbing where it got banged around a bit and it still works. COMFORT Unfortunately what the watch has in user interface usability, it totally lacks in comfort. The strap is a huge disaster. It is very rigid and uncomfortable. The 'waffling' or indented designs near the bezel on each side of the strap create areas where the strap digs into the wrist. with any prolonged wearing, it gets worse and worse until your wrist is begging you to take it off. The strap is just absolutely godawful. I have read reviews where G Shock owners said it was very good, well though out and comfortable. If that is the case, I shudder to imagine what a G Shock is like on the wrist. If constant pinching around sensitive areas on the side of the wrist seems like it would be the kind of thing to bother you, avoid this watch. I tried swapping it for another Timex band, which amazingly enough was uncomfortable it a DIFFERENT area! It seems Timex doesn't put much thought into their bands-- no part of the band should dig into the wrist. That's just obvious. CONCLUSION I really want to like this watch, I do. It's good-looking. It's very usable in terms of features. But the strap is terrible, so much so that the watch is unwearable. Unfortunately it took me about a week to figure this out, during which time the watch got sufficient wear so that it is no longer new, returnable condition. I am keeping it, using it as a 'beater' watch in the gym (I put my watch on the ground in the gym). If you purchase it I recommend you wear it for a good few hours while not doing anything that will scratch it, so that you can return it if need be.
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Reviewed in the United States on October 5, 2014
P
Verified Purchase
@photobrow
Port Orchard, US
★★★★★ 5
Compared to g-shock?
Color: Black/Yellow
Firstly random public reviews can be comical…”it’s has a battery, terrible, One star” or “I don’t like yellow, one star” omg peoples do better. I’ll review this while comparing to an older style of g-shock from the same era. I’ll start by saying this timex rocks, for me in my mid 50’s it’s so retro and nastalgic, brings back memories, I may have even owned this model back in the day. What’s great about it- the display, larger digits than the typical g-shock and they are super crisp, clear and easy to read. The indiglo is awesome. This is the most accurate quartz watch I have aside from the atomic g-shocks that adjust themselves daily. I prefer a chunky watch and the g-shocks do a better job in that department. i feel this watch is rugged, but I’d still give the nod to g-shock in this department. 200M water resistance is the gold standard and this watch has it which I love for peace of mind for any water based activities. This is a 5 star watch at a great price. I still love some aspects of a g-shock better but its just preference.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 11, 2026

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