Description

The Mercury MerCruiser Quicksilver 26-43035 is a genuine Mercury Marine OEM upper driveshaft oil seal used in select Mercury and Mariner outboard lower-unit and gearcase assemblies. This seal is installed in the driveshaft sealing area where the factory gearcase diagram calls for 43035 / 26-43035, helping retain gear lubricant inside the lower unit while helping protect the gear housing from water intrusion around the driveshaft.

Key Features

• Genuine Mercury Marine factory OEM oil seal.
• Mercury/MerCruiser part number: 26-43035.
• Manufacturer part number: 43035.
• Official part label: SEAL Oil.
• GTIN/UPC: 745061149663.
• Listed shipping weight: 0.02 lb.
• Listed shipping dimensions: 1.50 in. L x 1.50 in. W x 0.25 in. H.
• Used in select lower-unit, gearcase, driveshaft, and water-pump-base-related sealing locations where specified by Mercury diagram.

Application Compatibility

Common where-used application groups include select Mercury and Mariner outboards by serial number and gearcase configuration, including:

• 45 Bodensee 4-Stroke applications
• 45 Jet applications
• 50 HP 3-cylinder applications
• 50 HP 4-Stroke / BigFoot / EFI 4-Stroke applications
• 55 HP and 60 HP 3-cylinder applications
• 60 HP BigFoot and 60 EFI 4-Stroke applications
• 65 Jet and 80 Jet applications
• 70, 75, 80, and 90 HP 3-cylinder applications
• 75, 90, 115, and 125 DFI 1.5L 3-cylinder applications where specified
• 75, 80, 90, 100, and 115 EFI 4-Stroke applications where specified
• 100, 115, 120, and 125 HP 4-cylinder applications where specified

Use this seal only where the Mercury lower-unit or gearcase diagram specifically calls for 26-43035 / 43035.

Fitment Notice

Confirm fitment by engine serial number, gearcase style, driveshaft diameter, and exact diagram location before ordering. Mercury used different driveshaft seals, water pump base seals, shift shaft seals, and propeller shaft seals across similar horsepower ranges, so horsepower alone is not enough to confirm fitment.

When This Part Needs Replacement

Replace this oil seal if gear lube appears milky, water is found in the lower unit, gear oil is leaking from the upper driveshaft area, or the seal is removed during water pump base or gearcase service. It should also be replaced if the sealing lip is hardened, cut, distorted, corroded around the casing, or worn from driveshaft surface damage.

Installation Notes

Inspect the driveshaft sealing surface before installing the new seal. A grooved, pitted, or corroded driveshaft can damage the new seal and cause repeat leakage. During lower-unit service, also inspect the water pump base, related gaskets, shift shaft seal, propeller shaft seals, drain/fill screw gaskets, and gearcase pressure/vacuum test results. Follow the Mercury service manual procedure for the correct seal orientation and installation depth for the specific gearcase.

Alternate/Superseded Part Numbers

• 26-43035 — Mercury/MerCruiser formatted part number
• 43035 — Manufacturer part number
• 26-43035A4 — related lower-unit gearcase seal kit reference; verify by serial number and gearcase diagram
• Sierra 18-0583 — aftermarket cross-reference commonly associated with this seal
• Honda 91251-ZW1-003 — cross-reference to verify by application
• Chrysler/Force 26-43035 — legacy/application reference to verify by gearcase

Parts Desk Insight

Water in the lower-unit oil is rarely solved by replacing one seal at random. This driveshaft oil seal should be inspected along with the water pump base, shift shaft seal, prop shaft seals, and drain screw gaskets, then confirmed with a pressure/vacuum test before the lower unit goes back into service.

Shipping: Ships same or next day for fast Canada wide shipping.