Description

Overview

Manual slack adjuster 28 spline suits Rockwell axle S-cam brake setups using a 1 1/2″ (38mm) camshaft interface and 3/4″ adjusting nut. This two-hole version provides 140mm and 165mm arm positions, so the linkage can be matched to the existing brake chamber and cam geometry.

Features

• Manual adjustment through a 3/4″ adjusting nut.
• 28-spline 38mm camshaft interface.
• Two arm positions at 140mm and 165mm.
• 12.7mm clevis pin connection size.

Specifications and Materials

Spline count: 28. Spline size: 1 1/2″ (38mm). Arm holes: 2. Arm length A: 5 1/2″ (140mm). Arm length B: 6 1/2″ (165mm). Clevis pin diameter: 1/2″ (12.7mm).

Part number: FB4993.

For brake servicing context, see the HVIA brake servicing and maintenance guide

Compatibility and Fitment

Confirm the 28-spline 38mm camshaft, two-hole arm, 140mm and 165mm lever positions, 12.7mm clevis pin and 3/4″ adjusting nut before fitting. A similar 28-spline adjuster with different arm positions or hole count changes brake chamber linkage geometry. These cross-references show where this part replaces the part numbers and applications listed. Some installations may need minor changes. BP5024-1, BP50241, 10.368B, 10368B

Compliance and Safety

Inspect the camshaft splines, clevis connection, pushrod alignment and adjuster movement during installation. Then set brake adjustment to the vehicle or axle service procedure and confirm the pushrod travels freely without binding through a full brake application.

Trailer Applications

This manual slack adjuster 28 spline fits compatible Rockwell axle S-cam brake assemblies where a two-position 140mm or 165mm lever and 3/4″ manual adjusting nut match the existing setup.

Cross-reference and Suitability

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

Why Choose ICS Trailers

The decisive checks on this adjuster are the two-hole 140/165mm arm layout, 28-spline 38mm drive and 12.7mm clevis connection. If the old part is worn or its markings are unclear, send ICS Trailers a photo of the adjuster fitted to the axle plus the camshaft and arm measurements. We can help compare the linkage geometry before the brake is adjusted and returned to service.

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