D390 Heavy-Duty V-Belt — Dayco D390GL, Timken DP390

The D390 V-belt is a large classical-section belt for compatible heavy-duty sheaves. Dayco's official Gold Label table publishes D390GL as the same D-section inside-length designation.

Cross-Reference Information

Measurement warning: The D number and Dayco GL number use inside length. Datum and outside length are different measurements and should not be substituted without checking the drive specification.

Common Symptoms

• Belt slips under heavy load
• Excessive heat, noise or belt dust
• Driven equipment loses speed or torque
• Belt is cracked, glazed or damaged along the cover

Check Before Replacing

• Confirm D-section sheaves and the complete original marking
• Inspect grooves for wear and correct groove angle
• Check alignment, shaft condition and bearings
• Use the specified matched set when the drive uses multiple belts

Installation Notes

1. Disconnect and lock out power.
2. Relieve tension without prying the belt over a sheave.
3. Inspect and clean all drive components.
4. Align the sheaves and tension to the equipment specification.
5. Reinstall guards and test under controlled load.

Verified Compatible Equipment Models

No model-level fitment was published for this universal D-section size. Official sources identify broad heavy industrial applications. Match the original belt designation, profile, length system and drive requirements.