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Sierra 18-3704 Marine Propeller Nut for Mercury/Mariner Outboard Engines

Manufacturer

Picture for manufacturer Sierra

Part Number

18-3704
13 reviews
Sale Price

$21.59

3 left at this price

delivery box

Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-3704 is a marine-grade replacement propeller nut designed for Mercury and Mariner outboard engines in the 30–70 HP range. It directly replaces OEM Mercury Marine part number 11-69578 and is a direct-fit aftermarket alternative engineered to meet or exceed original equipment specifications.

Key Features:

  • Direct OEM replacement for Mercury Marine prop nut 11-69578
  • Compatible with Mercury/Mariner outboard engines, 30–70 HP
  • Interchangeable with GLM 21240 and Mallory 9-73901
  • Cross references: SIE 3704, SIE18-3704, 0418-3704, 04183704
  • Part of the Sierra 18-3702 Prop Nut Kit (which includes two tab washers)
  • Manufactured by Sierra International to meet stringent marine industry standards

Sierra International is a trusted name in marine aftermarket parts, offering premium-quality replacements across thousands of marine applications. The 18-3704 prop nut ensures a secure propeller connection, helping to maintain safe and reliable outboard engine performance. Sold individually.

Easy to follow, and found what I was looking for at a very reasonable price. I will be back for more. Customer service very very friendly and helpful when i had to return a part. Was completely no hassle and will gladly keep shopping with Autoplicity for

So far, very easy. Price, Delivery Time and Quality were very Good. Thank You.

Easy to navigate. Good pricing

Site is simple and easy to use.

great so far,hope to be notified of shipping

The site showed items in stock, I hope that was accurate

Thank you for the great prices

This was my first time buying from Autoplicity. I had never heard of the site but gave it a shot. I ordered an Autometer gauge and pod and paid less than the price of just the gauge at other vendors. The two items shipped a day later (I ordered Sunday, shipped Monday). I have no complaints at this time.

easy ordering!

By far the best price I found on a Bak flip bed cover! Shipped the next day, although I did have to call to get the tracking number. However, customer service was very nice and emailed me the tracking number immediately. I will do business here again!

Quick and easy

Excellent.

Excellent prices. Delivery was fast. Great site to order parts from.

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