SKF 31581 Engine Crankshaft Seal - Rear

SKF 31581 Rear Crankshaft Seal Overview

SKF 31581 is a rear crankshaft seal for engine sealing applications where oil control at the rear of the crankshaft is critical. It is built with a silicone sealing surface type and sized for a 3.150 shaft diameter, with a 3.944 outside diameter and 0.394 width for the specified application.

As part of SKF’s Crankshaft Rear Seal - Rear line, this seal reflects the brand’s long history in shaft sealing design and bonded seal development. SKF 31581 is made to specific design requirements using premium materials to help maintain proper sealing performance in demanding engine environments.

Key Features

• Rear crankshaft seal for engine oil sealing at the back of the crankshaft
• Silicone sealing surface type for the listed application
• Width: 0.394
• Outside diameter: 3.944
• Shaft diameter: 3.150
• SKF part number 31581 for direct identification

Detailed Description

SKF 31581 is an engine crankshaft seal designed for rear main sealing service on select Nissan, Toyota, and Volvo applications. It is a fitment-based replacement for vehicles including the Nissan 240SX, Nissan Altima, Toyota 4Runner, Toyota Pickup, Volvo 760, and Volvo 780. This part number 31581 is specified for rear position use and is sized to match the listed shaft and housing dimensions.

This SKF rear crankshaft seal supports oil retention at the rear of the engine while helping keep contaminants out of the sealing area. This part cross-references 1218353-9 and 9031180010 for the same application.

Vehicle Fitment

• Fits 1990-1998 Nissan 240SX, rear
• Fits 1993-1995 Nissan Altima, rear
• Fits 1991-1995 Toyota 4Runner, rear
• Fits 1991-1995 Toyota Pickup, rear
• Fits 1990 Toyota 4Runner, rear, From 6/90
• Fits 1990 Toyota Pickup, rear, From 6/90
• Fits 1988-1990 Volvo 760, rear
• Fits 1988-1990 Volvo 780, rear
• Fits 1989 Nissan 240SX, rear, From 7/89
• Fits 1989 Nissan 240SX, rear, Thru 7/89

What It Helps Address

• Rear engine oil leaks at the crankshaft sealing area
• Oil seepage that can contaminate the bellhousing or transmission area
• Loss of crankcase oil from a worn rear seal
• Contamination entering the rear seal interface
• Seal replacement needs during engine service on listed Nissan, Toyota, and Volvo models

Installation Notes and Tips

Confirm the shaft diameter, outside diameter, and width against the original seal before installation. Inspect the crankshaft sealing surface for wear, scoring, or contamination, and clean the sealing area thoroughly before fitting the new seal. Verify rear-position application and model-year coverage for your vehicle, including the noted production breakpoints on 1989-1990 Nissan 240SX and 1990 Toyota 4Runner and Pickup.

Quality Assurance

SKF has a long history in shaft seal engineering, including early integrated seal development and ongoing refinement of bonding methods and material selection. SKF 31581 is manufactured to high quality standards for long service life and dependable sealing performance in the specified application.