5261322 | Genuine Cummins® Fan Support for ISB 6.7, QSB 6.7

• Cummins® Engine Platforms: ISB 6.7, QSB 6.7, and ISB6.7 CM2350 heavy-duty/industrial diesel engines.

• Commercial & Vocational Trucks: Freightliner® (M2 106, Custom Chassis), International®/Navistar®, Ford® (F-650, F-750 with 6.7L Cummins), and RAM® 2500/3500 chassis cabs.

• Buses & Commercial Transit: Blue Bird®, Thomas Built Buses®, and IC Bus® commercial and school buses.

• Construction, Agricultural, & Industrial Equipment: Komatsu® excavators, Case IH® tractors, Hyundai® wheel loaders, and stationary power generators driven by QSB 6.7 engines.

1. What is it?

Part serves as the central rotational anchor for the engine’s radiator cooling fan and drive pulley. It houses a heavy-duty double-row roller bearing pressed into a cast-iron mounting bracket, isolating radial loads generated by the serpentine belt and fan clutch while maintaining precise alignment.

2. Core Functions & Technical Features

• Rotational Support & Alignment: Holds the fan pulley and clutch in exact alignment with the accessory drive system, preventing belt slippage, throw, or uneven rib wear.

• Heavy-Duty Load Absorption: Absorbs severe rotational vibration and gyroscopic forces exerted by large, multi-blade radiator cooling fans during engagement.

• Integrated Sealed Bearings: Features high-temperature internal roller bearings pre-packed with synthetic grease to withstand high engine bay thermal stress without frequent maintenance.

• Precision Structural Mount: Cast from high-tensile ductile iron to prevent flexing or fatigue fracturing under full cooling load.

1. High-Pitched Whining, Grinding, or Squealing from Engine Front

• Symptom: A sharp grinding, metallic growl, or loud screeching noise originating from the upper front drive belt area that changes pitch with engine RPM.

• Cause: Internal double-row bearings losing lubrication, causing metal-to-metal friction and bearing race scoring inside the support hub.

2. Visible Fan Wobble, Pulley Play, or Belt Misalignment

• Symptom: The engine fan blade/clutch wobbles noticeably while idling, or the drive pulley exhibits physical play when rocked by hand (engine off).

• Cause: Severe internal bearing wear or shaft play, causing the pulley flange to tilt out of alignment with the main serpentine belt.

3. Excessive Serpentine Belt Wear, Chirping, or Shredding

• Symptom: The drive belt continuously chirps, shows uneven rib wear, strays off the pulley track, or frays along the edges.

• Cause: The tilted fan support shaft misaligns the belt, throwing extra lateral tension on adjacent pulleys (alternator, tensioner, water pump).

4. Engine Overheating / Intermittent Radiator Fan Engagement

• Symptom: Engine coolant temperatures climb abnormally high, especially under heavy load or at low road speeds.

• Cause: Increased mechanical resistance from a binding fan support bearing preventing the fan from reaching its full engaged rotational speed.