Most other bikes have the engine, gearbox, and clutch all submerged in the same oil, with free flow between all sections. In contrast, Moto Guzzis have a seperate crankcase oil, gearbox oil, and bezel drive oil. the clutch is dry singe-plate, much like a car.

The factory calls for gearbox oil replacement every 18,000mi (30,000km), same as the bezel drive.

Requirements

Tools

  • 17mm spanner/socket
  • allen key
  • oil catch tray
  • if you have the stock catalytic converter, you need to fashion a chute out of plastic to redirect the oil over the top of the cat, or else clean the cat after it has oil dumped on it

Parts

  • 700cc of 75W-140 synthetic gearbox oil (SAE 75W-140 - API GL5). if you buy 1l of this, it can also do the bevel drive
  • copper crush washer of (i believe) 10x14x1.5mm (same as the engine and the bevel box drain washers)

Procedure

  1. undo the drain bolt, and drain the oil into the catch tray. if you’re using a decat pipe, the oil will fall straight down to the catch tray, if not, you’ll need to redirect the oil around the cat or let it get oily.
  2. check the drain bolt magnetic tip for metal shards. a small amount of fuzz is ok, big chunks are not.
  3. remove the old crush washer, replace with a new one, and tighten the drain bolt to 50Nm
  4. open the fill cap, pour in approximately 700cc of oil, and replace the fill port cover, hand-tightening