Description

Overview

The inner bush 41mm nylon is a camshaft support sleeve for Rockwell trailer brake cams that helps keep the shaft running true inside the brake spider. It locates the camshaft radially so the brake shoes can apply evenly under load. As a result, the bush supports consistent brake response on busy fleet trailers where reliability matters.

Features

This inner bush 41mm nylon design uses a precision 41mm internal diameter to match Rockwell camshafts and help minimise free play. The 48mm outer diameter also provides a snug press fit in the housing so the bush resists movement during operation. The 28mm length offers a stable bearing surface while still fitting common brake spider pockets. The nylon construction can also help damp vibration and can run with limited lubrication in harsh trailer environments.

Specifications and Materials

This bush is a plain, cylindrical sleeve with a nominal length of 28mm, an internal diameter of 41mm and an outer diameter of 48mm, matching typical Rockwell 1 5/8 inch brake camshaft hardware stacks. The inner bush 41mm nylon body functions as a non-metallic bearing surface between the hardened camshaft and the surrounding steel components. Nylon offers low friction and good wear resistance for rotary bearing applications when correctly installed and kept free of contamination. Part number: FB3120.
For a wider technical background on how plain bearings and bushings support rotating shafts, see this plain bearing overview

Compatibility and Fitment

This cross-reference listing means this part is a suitable replacement for the part numbers and applications shown. Some changes in installation may be required. 1225B834, 28-1241, BP3120, FL28.1241, WT3120

Compliance and Safety

Correctly supporting the brake camshaft helps maintain predictable brake balance, which is important for meeting heavy vehicle roadworthiness obligations. Regular inspections should confirm the inner bush 41mm nylon sleeve is not cracked, deformed or excessively worn, and that there is no abnormal camshaft movement. In addition, follow the trailer or axle manufacturer’s procedures for camshaft and foundation brake service, and chock wheels and isolate air supplies before starting any work.

Trailer Applications

This bush suits Rockwell 1 5/8 inch brake camshafts used on many semi-trailers, dollies and other heavy transport equipment. In service, it works with matching outer bushes, seals and washers to keep the camshaft aligned through repeated brake applications. As a result, a fresh inner bush 41mm nylon sleeve can help restore correct camshaft support when upgrading or rebuilding worn foundation brake hardware on fleet trailers.

Cross-reference and Suitability

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

This layout makes it easier to confirm interchange options when replacing existing camshaft bushes in Rockwell-based brake systems.

Why Choose ICS Trailers

ICS Trailers focuses on heavy trailer applications, so listed camshaft bushes are selected for real-world fleet use rather than light-duty automotive work. You can match this inner bush to other camshaft hardware, seals and foundation brake components from the same catalogue for a complete service kit. If you need help confirming suitability on a particular axle or suspension setup, the ICS team can assist with cross-checks against your existing parts. Browse Foundation Brakes at ICS Trailers via Foundation Brakes