1. Introduction
This manual provides essential information for the proper handling, installation, operation, and maintenance of the Timken 3780 Tapered Roller Bearing. Adhering to these instructions will ensure optimal performance and longevity of the product.
The Timken 3700 Series single cone is designed to be paired with a compatible single cup (outer ring, sold separately) to form a complete tapered roller bearing. This bearing system is engineered to effectively manage both radial and axial loads in various applications.

Figure 1: Timken 3780 Tapered Roller Bearing (Single Cone)
This image displays the Timken 3780 Tapered Roller Bearing, which is a single cone component. It features a series of tapered rollers held within a stamped steel cage, designed to interface with an outer cup (not shown) to form a complete bearing unit.
2. Product Overview and Components
The Timken 3780 is a single cone (inner ring) component of a tapered roller bearing. It is manufactured from Timken's high-alloy steel, providing durability, heat tolerance, and resistance to deformation under heavy loads. Key features include:
- Single Cone Design: Connects to compatible cups (outer rings, sold separately) to form a complete tapered roller bearing.
- Load Support: Capable of supporting both radial and axial loads between rotating and non-rotating members.
- Temperature Stability: The cone assembly maintains its integrity without significant contraction or expansion within an operating temperature range of -54 to 120 degrees C (-65 to 250 degrees F).
- Stamped Steel Cage: Ensures even spacing of rollers, which reduces friction, vibration, and noise during operation.
- Open Configuration: Designed for lubrication to be applied in place, allowing for periodic reapplication and accurate adjustments.
What's in the Box:
- One (1) Timken 3780 Tapered Roller Bearing (Single Cone)
3. Setup and Installation
Proper installation is crucial for the performance and lifespan of the tapered roller bearing. This single cone must be assembled with a compatible outer cup (sold separately) to form a complete bearing unit.
- Preparation: Ensure all mating surfaces on the shaft and housing are clean, free of burrs, and properly machined to the correct tolerances.
- Lubrication: Apply a thin, even coat of compatible grease (see Maintenance section) to the cone bore and roller surfaces before installation.
- Cone Installation: Press the Timken 3780 single cone onto the shaft. Ensure it is seated firmly against the shaft shoulder or spacer. Use appropriate tools to avoid damaging the bearing.
- Cup Installation: Install the compatible outer cup into the housing bore.
- Assembly: Carefully assemble the shaft with the installed cone into the housing with the installed cup.
- Adjustment: Tapered roller bearings typically require a specific amount of axial play or preload. Refer to the equipment manufacturer's specifications for the correct bearing setting procedure. This often involves adjusting the axial position of one of the bearing components until the desired setting is achieved.
- Paired Mounting: For applications requiring even load distribution, these bearings are generally mounted in opposing pairs on a shaft.
Important: Always consult the specific equipment manufacturer's manual for detailed installation instructions and torque specifications for your application.

Figure 2: Front View Dimensions
This technical drawing provides the front view of the Timken 3780 bearing, illustrating its primary dimensions including the inner diameter (ID) of 2.00 inches and an outer diameter of 2.93 inches.

Figure 3: Side View Dimensions
This drawing shows the side profile of the Timken 3780 bearing, detailing its height or overall dimension from the side, which is 3.67 inches, and the width of the cone at 2.82 inches.

Figure 4: Top View Dimensions
This illustration presents the top view of the Timken 3780 bearing, highlighting its width of 1.19 inches and a smaller dimension of 0.25 inches, likely representing a specific feature or chamfer.
4. Operating Principles
Tapered roller bearings are designed to accommodate combined loads, meaning they can handle both radial (perpendicular to the shaft) and axial (parallel to the shaft) forces. The conical shape of the rollers and raceways allows the bearing to distribute these loads efficiently.
- Load Distribution: When assembled with a cup, the tapered rollers roll between the cone and cup raceways. The angle of the taper allows the bearing to support significant axial loads in one direction, in addition to radial loads.
- Friction Reduction: The rolling elements (tapered rollers) minimize friction between moving parts, enabling smooth rotation and reducing energy consumption.
- Heat Management: The design and material properties of the Timken 3780 bearing allow it to operate effectively within its specified temperature range, preventing premature wear due to thermal expansion or contraction.
- Applications: This bearing is suitable for high-load, moderate-speed applications, commonly found in automotive axle systems, conveyor systems, and heavy-duty industrial machinery in sectors such as mining, construction, and agriculture.
5. Maintenance
Regular maintenance, particularly proper lubrication, is vital for extending the service life of your Timken 3780 Tapered Roller Bearing.
- Lubrication: The Timken 3780 bearing is an open-configuration component, meaning it requires lubrication to be applied in place. The compatible lubricant for this bearing is grease.
- Reapplication Schedule: Lubrication should be reapplied periodically based on the bearing's use, operating conditions (temperature, speed, load), and environmental factors. Consult your equipment's maintenance schedule or a bearing lubrication guide for specific intervals.
- Lubricant Type: Always use a high-quality, compatible grease recommended for tapered roller bearings and your specific application's operating conditions. Incompatible lubricants can lead to premature bearing failure.
- Inspection: Periodically inspect the bearing for signs of wear, corrosion, or contamination. Address any issues promptly.
- Cleaning: If the bearing needs cleaning, use appropriate solvents and ensure it is thoroughly dried and re-lubricated before reassembly. Avoid using high-pressure washes directly on the bearing.
6. Troubleshooting
While tapered roller bearings are robust, issues can arise. This section provides general guidance for common problems. For complex issues, consult a qualified technician or Timken support.
| Symptom | Possible Cause | Solution |
|---|---|---|
| Excessive Noise / Vibration |
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| Overheating |
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| Premature Failure |
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7. Specifications
| Attribute | Detail |
|---|---|
| Brand | TIMKEN |
| Model Number | 3780 |
| Bearing Type | Tapered Roller Bearing (Single Cone) |
| Material | High-Alloy Steel |
| Inner Diameter (ID) | 2.0000 inches |
| Width | 1.1930 inches |
| Item Dimensions (L x W x H) | 3 x 3 x 1 inches (approximate packaging) |
| Item Weight | 1 Pound |
| Operating Temperature Range | -54 to 120 degrees C (-65 to 250 degrees F) |
| Compatible Lubricant | Grease |
| Standards Met | ISO 355, ABMA standard 19.2, ISO 492, ISO 720 (as per product description) |
| Country of Origin | USA |
| UPC | 053893132310 |
8. Warranty and Support
For information regarding product warranty, technical support, or service, please contact Timken directly or refer to their official website. Keep your purchase receipt and product details (model number, date of purchase) handy when contacting support.
Manufacturer: Timken Company
Website: www.timken.com (Please note: This is a general placeholder for the manufacturer's website. Always verify the official website for the most accurate contact information.)





