Description

Overview

Automatic Slack Adjuster 28 Spline 38mm keeps brake adjustment consistent on truck and trailer setups, which helps maintain stable stopping performance. Because wear happens gradually, this automatic mechanism reduces the need for frequent manual take-up when the system is in good condition. The 28 spline input suits common 1 1/2″ (38mm) camshaft interfaces used across heavy vehicle foundation brakes, so you can restore correct adjuster function without changing the rest of the brake geometry when the spline and arm length match.

Features

This Automatic Slack Adjuster 28 Spline 38mm is built around fitment-critical geometry, so correct selection is straightforward.

• Automatic take-up design to help maintain correct running clearance
• 28 spline, 1 1/2″ (38mm) spline size interface
• Single mounting hole configuration for common applications
• 5 1/2″ (165mm) arm length to match standard linkage geometry

Specifications and Materials

Spline: 28. Spline size: 1 1/2″ (38mm). Number of holes: 1. Arm length A: 5 1/2″ (165mm). Clevis pin diameter: 5/8″ (16mm). Application: Truck & Trailer.

For setup and inspection procedures, refer to the Haldex automatic brake adjuster installation guide before fitting

Part number: FB4988.

Compatibility and Fitment

Confirm the spline count and spline size on the camshaft first, then match the arm length and hole style to your existing linkage. Also verify pushrod travel and clevis alignment because misalignment can cause uneven wear. This cross-reference listing means this part is a suitable replacement for the part numbers and applications shown, but some changes in installation may be required. A153275M1079, E15024, R801073, A24-3275M1079PZ

Compliance and Safety

Brakes are safety-critical, so install this adjuster only after confirming correct stroke, angles, and free movement through the full suspension range. Re-check adjustment after bedding-in because linings and drums can settle. Inspect bushings, clevis pins, and chambers at the same time since worn hardware can mimic adjuster faults. Follow the vehicle or trailer service schedule and any workplace safety procedures during installation.

Trailer Applications

Automatic Slack Adjuster 28 Spline 38mm suits many heavy trailer and prime mover combinations where a 28 spline, 38mm camshaft interface is used. It can suit B-doubles, flat tops, tippers, and general freight trailers when the arm length and hole configuration match the existing setup. If you are converting from a different arm length, measure the installed geometry first because leverage and stroke limits must remain within spec.

Cross-reference and Suitability

This part cross-references to or suits the following equivalent part numbers and compatible alternatives:

Why Choose ICS Trailers

ICS Trailers helps you match braking components by the details that matter, so you can avoid costly downtime from wrong-fit parts. Our range supports common heavy vehicle and trailer braking setups, which makes it easier to keep fleets consistent. If you are unsure, compare your existing adjuster measurements and spline details before ordering to keep installation smooth. To compare options, use Browse Air Brake Parts at ICS Trailers and match the spline and arm length to your setup.