|Triumph Pre-Unit Offset Crankshaft|
Typical all-welded pre-unit Triumph crankshaft before balancing and nitriding. This crank is shown before heat treating and balancing has been done to show welding. Pre-unit cranks are made from the same alloy steel as later one-piece forged Triumph cranks but have a different thread pitch for the timing gear. The spline depths also very. We check that the pre-unit cush drive sleeve fits the spline and seats properly against the drive-side bearing. An in-line oil filter is recommended because there was no sludge trap in a pre-unit crankshaft. All cranks supplied with bearing shells.