BMW F20 F21 F30 F31 LCI Hose Radiator Transmission Oil Cooler 8662837

BMW F20 F21 F30 F31 LCI Hose Radiator Transmission Oil Cooler is an original transmission cooling system component, designed for BMW 1 Series and 3 Series models after the facelift (LCI). Thanks to its factory geometry and precisely selected hose diameter, it ensures stable heat dissipation from the transmission oil, which translates into safe drivetrain operation and reduces the risk of overheating. This is a practical solution for users looking for parts structurally matched to a specific BMW generation.

Specifications and technical data

• SKU: 8662837
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8662837
• Substitutable numbers: 8662837, 17128662837
• Category: Oil Coolers & Lines

Purpose and function in the transmission cooling system

The presented hose is a component from the Oil coolers and hoses group, responsible for transporting transmission oil between the gearbox and the heat exchanger or oil cooler. A correctly selected hose:

• maintains proper coolant flow in the transmission circuit,
• stabilizes the transmission operating temperature during city and highway driving,
• limits pressure drops in the system thanks to the correct cross-section and length,
• supports the durability of internal transmission components by reducing the effects of oil overheating.

For modern BMW F-series models, maintaining the proper transmission oil temperature is crucial for smooth gear shifting and the longevity of the entire drivetrain.

Construction and fitment for BMW F20, F21, F30, F31 LCI

The transmission cooler hose in this version has been designed specifically for the architecture of the F20/F21 (1 Series) and F30/F31 (3 Series) bodies after the LCI modernization. This means:

• geometry matched to the factory routing of hoses in the engine bay,
• designed for specific mounting points and brackets,
• compatibility with original oil cooler connectors and transmission housing.

As a result, installation is straightforward, without the need for modifications or additional adapters, and the hose maintains the correct positioning relative to other auxiliary components.

Benefits of using an original BMW hose

Using a hose from the same design line as factory BMW components provides a number of practical benefits:

• Consistency with the cooling system design – the hose works with the factory oil cooler and transmission in accordance with the manufacturer's specifications.
• Reduced risk of leaks – the proper profile of the ends and fitment to original connectors minimize the risk of oil leaks.
• Stable operating parameters – maintaining the cross-section and length specified by the manufacturer helps maintain proper pressure and flow.
• Easier diagnostics – the mechanic works with a system built from components compliant with BMW service documentation.

Condition, service application, and selection by parameters

The item comes from the BMW range and is intended for service applications in vehicles where the factory transmission cooling hose has been damaged, cracked, or delaminated. Replacing the hose is recommended, among other things, in the event of:

• detected oil leaks in the vicinity of the transmission cooler,
• visible mechanical damage to the hose,
• work on the oil cooling system requiring the removal of hoses.

For correct part selection, it is worth using the manufacturer's markings and vehicle data, such as model, generation, and transmission type, which facilitates precise matching of the component to the specific car configuration.

Technical support and additional information

A properly functioning transmission oil cooling system is closely linked to the overall condition of the vehicle's cooling system. To better understand the relationships between the engine radiator, oil cooler, and powertrain durability, it is worth reading the article: Engine cooling system – overheating, repair, and used radiators. You will find practical tips there regarding diagnostics and maintenance of components responsible for heat dissipation.

If you are planning a comprehensive repair or upgrade of the oil cooling system area in your BMW and need other elements from the same group, such as hoses, connectors, or additional installation sections, check the available parts in the BMW oil coolers and hoses category.