SKF 39139 Engine Crankshaft Seal - Rear

Engine Crankshaft Seal Overview

SKF 39139 is an engine crankshaft seal built for rear applications on select BMW models. It uses a nitrile sealing surface and application-specific dimensions to help maintain proper sealing at the crankshaft interface.

Fits select BMW 540i, M5, X5, Z8, 740i, 740iL, 750iL, 840Ci, 850Ci, 530i, 850CSi, and 850i rear applications. Part number 39139 is a direct reference for buyers searching for a rear crankshaft seal for BMW engine sealing service.

Key Features

• Nitrile sealing surface for engine oil sealing applications.
• Specified width, outside diameter, and shaft diameter for application matching.
• Rear crankshaft seal design for select BMW engines.
• SKF sealing engineering backed by long-running OE-style manufacturing practices.

Detailed Description

SKF 39139 is an engine crankshaft seal engineered for rear installation points on a wide range of BMW applications. The seal is specified with a 0.472 width, 4.929 outside diameter, and 3.937 shaft diameter, helping ensure the part matches the intended crankshaft sealing interface. The nitrile sealing surface is selected for engine oil sealing performance in the operating environment of the application.

SKF has a long history in seal development, including early integrated shaft seal design and continued refinement of bonding and material selection. For buyers servicing BMW 540i, BMW 740i, BMW 740iL, or related models, part number 39139 provides a focused replacement option for rear crankshaft sealing service. This part cross-references Monroe Shocks & Struts (e.g., 145839139, 975939139) for the same application.

Common Problems This Part Addresses

• Oil seepage at the rear crankshaft sealing area.
• Contamination entering the engine sealing interface.
• Seal wear from age, heat, and normal engine operation.
• Loss of proper crankshaft oil retention during service intervals.

Installation Notes and Tips

Confirm shaft diameter and seal dimensions before installation. Inspect the crankshaft sealing surface for wear, scoring, or contamination before fitting the new seal. Clean the sealing area thoroughly and follow the vehicle service procedure for correct placement and alignment. For BMW rear crankshaft seal service, verify the application against the listed fitment before beginning work.

Quality Assurance

SKF designs and manufactures seals to specific application requirements using premium materials and established bonding techniques. The brand’s seal engineering heritage and manufacturing standards support consistent sealing performance and long service life.