OS Giken Movement Alteration Kit Binding on R154 - Bracket Orientation & Bellhousing Clearancing

Transmissionadvanced✓ Community Verified

Problem

OS Giken movement alteration kit (clutch fork modification) binds and does not sit properly when installed on the R154 transmission bellhousing, preventing correct clutch operation.

Movement alteration kit fork/bracket binds during installationKit does not sit flat against bellhousingThrowout bearing is pushed forward and contacts clutch fingers when it should barely touch themVisible interference between kit and bellhousing support ribs

Root Cause

Two contributing factors: (1) The bottom fork bracket is shipped by OS Giken in the upside-down position, causing incorrect fitment. (2) The R154 bellhousing has internal support ribs that interfere with the movement alteration kit, preventing it from sitting flat.

Confidence

Moderate confidence — Multiple community members agreed on this solution

View Original Thread →Posted January 2018 on SupraForums.com