Hayden 5986 Accessory Drive Belt Idler Assembly

Hayden 5986 Idler Assembly

The Hayden 5986 accessory drive belt idler assembly is built for BMW accessory drive systems that use a back idler, grooved pulley, or smooth pulley layout. With a black plastic pulley body, 1.000 in. belt width, and a 1.01 in. inside diameter, it is a direct-fit service part for select BMW 750iL, 850i, 850Ci, and 850CSi applications.

Use this Hayden Idler Assembly when servicing the accessory drive belt system on BMW models that require stable belt routing and consistent pulley alignment. The Hayden 5986 is a practical OE-style replacement for worn idler hardware in air conditioning, alternator, and power steering belt drive applications.

Key Features

• Accessory drive belt idler assembly for BMW belt drive service
• Black plastic construction with a single-groove pulley design
• 1.000 in. belt width and 23.9 mm pulley width
• 74.613 mm outside diameter for specified belt routing applications
• Two mounting holes with 0.25 in. mounting hole diameter
• Cross-references Continental 49054 and Dayco 89092 for the same application
• Hayden 5986 part number for catalog and fitment lookup

Detailed Description

The Hayden Idler Assembly line focuses on accessory drive belt system components that keep belt routing stable across engine-driven accessories. Part number 5986 is a black, plastic idler assembly with a 1.01 in. inside diameter, 2.9375 in. outside diameter, and 4.66 in. overall length. It is listed for BMW 750iL, 850i, 850Ci, and 850CSi applications across air conditioning, alternator, power steering, grooved pulley, and smooth pulley positions. If you are replacing a worn BMW accessory drive belt idler assembly, the Hayden 5986 provides the correct style and dimensions for the specified fitments.

Compatible With BMW 750iL, BMW 850i, BMW 850Ci, and BMW 850CSi applications where the accessory drive belt system uses this idler assembly configuration. This part cross-references Continental 49054 and Dayco 89092 for the same application.

Common Problems This Part Addresses

• Belt noise caused by a worn or rough idler pulley
• Improper belt tracking in the accessory drive belt system
• Visible pulley wear or cracking on the idler assembly
• Loss of belt stability in air conditioning, alternator, or power steering drive routing
• Service replacement for aging BMW belt drive hardware

Installation Notes and Tips

Verify pulley style, belt width, and mounting-hole layout against the removed part before installation. Confirm the application position listed for your vehicle, since this idler assembly is used in multiple BMW accessory drive configurations. Inspect the belt, tensioner, and adjacent pulleys at the same time so the new idler assembly is installed into a clean, aligned belt path.

Fits 1988-2001 BMW 750iL, N/A; Fits 1988-1993 BMW 750iL, Alternator; Fits 1988-1993 BMW 750iL, Power Steering; Fits 1988-1993 BMW 750iL, Grooved Pulley; Fits 1988-1993 BMW 750iL, Smooth Pulley; Fits 1988-2001 BMW 750iL, Air Conditioning; Fits 1991-1992 BMW 850i, N/A; Fits 1991-1992 BMW 850i, Air Conditioning; Fits 1991-1992 BMW 850i, Alternator; Fits 1991-1992 BMW 850i, Power Steering; Fits 1991-1992 BMW 850i, Grooved Pulley; Fits 1991-1992 BMW 850i, Smooth Pulley; Fits 1993-1997 BMW 850Ci, N/A; Fits 1993-1997 BMW 850Ci, Air Conditioning; Fits 1993-1997 BMW 850Ci, Alternator; Fits 1993-1997 BMW 850Ci, Power Steering; Fits 1993-1997 BMW 850Ci, Grooved Pulley; Fits 1993-1997 BMW 850Ci, Smooth Pulley; Fits 1994-1995 BMW 850CSi, N/A; Fits 1994-1995 BMW 850CSi, Air Conditioning; Fits 1994-1995 BMW 850CSi, Alternator; Fits 1994-1995 BMW 850CSi, Power Steering; Fits 1994-1995 BMW 850CSi, Grooved Pulley; Fits 1994-1995 BMW 850CSi, Smooth Pulley.

Quality Assurance

Hayden is a recognized name in accessory drive belt system components, and the 5986 idler assembly is cataloged with direct interchange references for application matching. Use the part number 5986 and the listed BMW fitment details to confirm the correct replacement before service.