Crankshaft - GT and 750SS Roundcase

All the roundcase cranks used a 36mm diameter pin. In reality without further modifications to the lubrication system, meticulous frequent changing of the oil and cleaning the crankshaft sludge traps the pins were known to fail.

The strength of the conrods was never an issue. Today, sleeved GT rod sets on 38mm stepped pins are used  in some race bikes. The milled chrome moly twin web rods of the 750SS are lighter and stronger but are rarely used, they're too precious !


This crank and rod set ( 750SS ) has been trued, balanced, machined and modified  but not lightened. The rods were polished at the factory after milling.


The GT crank half and rodset pictured above differ significantly from the 750SS. Compare the images to note the differences. The pinion shown on the crank half drives the oil pump gear, unique to the roundcase engine.

The refurbishing of a crank and rod set should only be entrusted to a specialist with the correct tooling and knowledge of Ducati requirements.

The cases are about to be buttoned up. You can see the extra machining on the crankshaft to help oil drain off quickly.  A new gasket was used after all the shimming was carried out and measured with the case halves buttoned up at the recommended torque. Dummy engine mount bolts from 10mm allthread were used. The merest of smear of Loctite 515 Master Gasket was applied to the new gasket.

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