Ducati MONSTER 821 Workshop Manual page 1139

At each overhaul it is recommended to replace also the sealing ring (23) positioned outside gearbox
secondary shaft bearing (16) on crankcase outer side (12), on chain side.
Upon assembling, lubricate ring (23) with KLÜBERPLUS S 06/100 (or denatured alcohol), then fit it as
shown.
At each overhaul it is recommended to replace also the sealing ring (24) positioned outside timing layshaft
bearing (19) on crankcase outer side (13), on clutch side.
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