Oil Canister

Canonical Paper (PDF)

Canonical format: PDF
Build system: LMX
Current revision: v0.1

Abstract

This paper documents the geometry of the later-style BMW Airhead oil filter canister and explains how unintended radial jacking during installation can plastically deform the canister mouth, alter gasket stack-up, and increase sealing risk.

The objective is practical: help owners understand the interface, recognize the failure mechanism, and avoid repeating it.

Scope and Assumptions

Linear elastic behavior is assumed except where noted (localized yielding at the canister mouth is the observed failure mode).
The investigation focuses on the canister mouth, filter cover interface, and common service procedures.
The engineering interpretation emphasizes failure prevention rather than post-hoc fault assignment.

Key Takeaway

If the installation process creates an eccentric point contact that drives the canister laterally, the canister behaves as a short, stiff cylindrical shell. It will walk within its bore and locally deform the canister mouth, reducing radial clearance and causing tightening torque to rise earlier and more abruptly than expected.

Revision History

v0.1 — Initial public release (PDF is the authoritative version).