The NTN 4T-30311D (also known as 30311D) is a single-row tapered roller bearing engineered to support both radial and axial loads in automotive and industrial applications. Its metric ISO series, conical rollers, and separable cone/cup design make it ideal for wheel hubs, axle ends, transmissions, and heavy rotating assemblies.
Technical Specifications
| Specification |
Detail |
| Brand |
NTN |
| Part Number |
4T-30311D (30311D) |
| Bearing Type |
Single-Row Tapered Roller Bearing |
| Inner Diameter (d) |
55 mm
|
| Outer Diameter (D) |
120 mm
|
| Width (B) |
29 mm (inner)
|
| Total Width (T) |
31.5 mm
|
| Static Load Rating |
~154 kN
|
| Dynamic Load Rating |
~132 kN
|
| Limiting Speed |
~2,900 rpm (grease), ~3,800 rpm (oil)
|
| Weight |
~1.6 kg
|
| Condition |
Brand New |
| Series Standard |
Metric ISO tapered (4T Series)
|
Overview: The tapered roller design supports combined radial and axial loads with a conical roller/raceway geometry, and the separable cone and cup allow precise preload and mounting arrangements (e.g., O, X, tandem) in automotive hubs and industrial shafts.
Automotive & Vehicle Fitment
Tapered roller bearings like the NTN 4T-30311D / 30311D are selected by dimension and OEM cross reference, not by a generic universal list — meaning they fit when a specific vehicle’s hub/axle parts call for a 55×120×31.5 mm tapered bearing.
Common Vehicle Applications
This bearing size is commonly found in automotive hub, axle and drivetrain assemblies, particularly in larger passenger vehicles, light commercial trucks, and vans where similar sized tapered bearings are specified (e.g., OE and aftermarket fitments):
✔ Wheel hub assemblies – front/rear hubs supporting axial + radial loads
✔ Axle ends / differential carriers – rear and front axles where combined loads occur
✔ Transmission output/input shafts – some gear assemblies requiring tapered bearings
Because vehicle parts catalogs typically use OEM reference numbers, you must verify your vehicle’s OEM bearing part number before ordering. When the OEM bearing references correspond to a 55×120×31.5 mm metric tapered bearing, the 4T-30311D is an appropriate replacement.
📌 Final fitment confirmation: Always match the OEM part number from your vehicle’s parts list (e.g., Nissan, Toyota, Mitsubishi, Hino axle/hub/differential part numbers) to ensure compatibility.
Where It’s Used (Typical Applications)
Automotive
-
Front & rear wheel hub bearings
-
Rear differential carrier bearings
-
Axle support bearings (pinion/side)
-
Transmission shaft support
Since this is a standard size bearing, it’s widely used in many vehicles that require this exact metric-series tapered roller bearing — from passenger cars to light and medium trucks — when the OEM bearing annotated in the service manual corresponds.
Industrial & Heavy Machinery
-
Gear reducers & gearboxes
-
Conveyor shafts
-
Construction equipment drives
-
Agricultural machinery hubs
-
Heavy rotating machinery
Tapered roller bearings handle large radial loads with axial thrust when mounted properly — essential in both automotive and industrial rotating systems.
Features & Benefits
✔ High Load Capacity: Supports combined radial and axial loads reliably.
✔ Separable Design: Cone and cup separate for easy mounting and precise preload adjustment.
✔ Versatile Mounting: Suitable for O, X, tandem arrangements for bidirectional axial load support.
✔ Durable Construction: Hardened steel rollers and rings for long life under stress.
✔ Open Bearing: Suited to applications with external lubrication and sealing.
