6-Leaf Slipper Spring for 12,000 lb Trailer Axles – 30" Long – 3" Wide
Part Number: 77-44-1
Heavy-duty 6-leaf slipper spring designed for trailers with 12,000 lb axle capacity. Built from sturdy steel with a 30" length and 3" width, it provides strength, flexibility, and smooth suspension performance for heavy trailers.
R&P Knowledge Hub
Suspension Design: Slipper springs slide inside a hanger or equalizer rather than using two spring eyes. This design is common on heavier trailers and allows the suspension to flex under load while maintaining consistent ride height.
Fitment Insight: On heavy-duty trailer springs, measurement details matter. Verify overall spring length, width, leaf count, spring capacity, axle rating, and eye dimensions before ordering.
Application Notes: This spring is intended for 12,000 lb trailer axle applications where a 3" wide, 30" long 6-leaf slipper spring is required.
R&P Repair Insight
Leaf springs usually fail from a combination of load stress, road shock, corrosion, and age rather than one single event. On heavy trailers, the warning signs often show up before a complete break.
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Metal Fatigue: Repeated flexing under load can eventually crack or break one or more leaves.
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Overloading: Running above rated capacity can flatten the spring pack, reduce ride height, and shorten service life.
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Rust and Corrosion: Moisture, road salt, and debris can weaken the leaves and accelerate failure at contact points.
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Worn Suspension Hardware: Bad hangers, equalizers, bushings, or alignment issues can place uneven stress on the spring.
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Visible Signs: Broken leaves, sagging ride height, uneven tire wear, harsh ride quality, or a trailer leaning to one side are common indicators it is time for inspection or replacement.
Features
- Multiple leaf design provides flexibility to absorb road shock
- Helps deliver smoother trailer ride
- Reduces suspension wear and stress on trailer frame
- Heavy-duty steel construction
Specifications
| Specification | Detail |
| Part Number |
77-44-1 |
| Number of Leaves |
6 |
| Spring Width |
3" |
| Length (Eye Center to End) |
30" |
| Eye Diameter with Bushing |
1" |
| Eye Diameter without Bushing |
2" |
| Axle Capacity |
12,000 lbs |
| Spring Capacity |
6,000 lbs |
Dimensional Reference Diagram
Use this diagram as a visual reference when checking overall spring length, width, and eye/end configuration against your existing suspension.
Fitment / Application
| Category | Details |
| Trailer / Suspension Type | Heavy-duty trailer slipper spring suspension systems |
| Axle / Capacity | 12,000 lb trailer axle applications |
| Notes | Confirm 30" overall length, 3" width, 6-leaf design, and eye dimensions before ordering or installation |
Included Components
| Quantity | Item |
| 1 | 6-leaf slipper spring – 30" long – 3" wide – for 12,000 lb trailer axles |
Verify all measurements, eye dimensions, leaf count, spring capacity, and axle fitment before installation.
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