Gear shift system and gearbox sprocket

The gear shift system is so called to differentiate it from the selector system which is inside the crankcase halves. The shift system is external to the crankcase and can be worked on without removing the engine from the frame.

The shift system starts with the gear lever On the Twins and Triples there are two standard levers. Both are interchangeable — the long fits the Twin, the "short' fits the Triple. The SFC and some GTLs, as well as some other earlier Twins, featured a heel and toe rocking lever, the SFC by way of a rear-set.

Each lever in its own way fits a spline using a clamp method of the conventional sort. An 0 ring and washer should always be fitted on the shaft before the lever is fixed; there is a machining in the cover to take the 0 ring. A little grease on it helps. (See the next section for cross-over gearchange systems). Inside the lever cover, which is fixed by three setscrews and washers is the shifting system. A gasket is used, as is flexible gasket sealant. The component parts are easy to remove as will be quite obvious once the cover is removed. The shift drive bushes directly into the inner gearbox cover and will pull straight out once its return spring is eased open. Also you will have to unhitch the shifter arm from the selector spindle. This spindle comes away with the inner cover on which it bushes.

The gearbox cover is off and the shift drive will come The selector spindle will come away once all the other away once its spring is released. It's in the top left components are away hand corner. This is a Triple because of the 'closed' shift drive

The gear selecting mechanism for Twin. Part numbers 34 and 29 are substantially different on the Triple. Part number 3 appears inside a framework instead of being hooked by part number 29

Two types of shift drive are fitted, the Twins have an 'open' one, the Triples a 'closed' one. They are not designed to be interchangeable.

With all the parts in their proper place, you should be able to adjust the shifting of the gears. Everything should be smooth, and the outer cover when fitted, must not bind or allow the shift drive to rattle. Tapping the outer cover as it is fixed may well help, however, spacing shims are used on the shift drive to ensure this. There is an eccentric adjusting screw which allows the foot lever to be used through its full travel, both up and down, so that the gear can be 'fully' selected. In other words there should be an equal amount of shift movement both up and down.

This eccentric is on a lock nut. Adjust this eccentric around, so that you achieve the proper level of movement. 4th and 5th gear selection sort this out in the best way, although all gears should be checked. Remember false neutrals will be the result if this is not spot on. There is no need for the outer cover to be fitted for the shift lever will fit the shift drive without.

To gain access to the gearbox sprocket, you must remove the inner gearbox cover (obviously the outer cover and shift mechanism must be removed first). This inner cover casting is held by four setscrews and washers. It too has a gasket and uses flexible gasket cement (one of those setscrews is hidden by the outer cover). Remove the inner cover by tapping it lightly with a hide-headed hammer so as to break the seal. Carefully pull it off. It will always be filthy because of chain lubrication. With it should come the selector spindle, (this meshes with the selector drum shaft which is held in the crankcase). The selector spindle bushes at its outer end on the outer cover and, in its centre on the inner cover. The spindle should pull out.

What you will now see is the gearbox sprocket and the end of the selector drum shaft end gear. (You can see just the shaft through the inner cover when it is fitted). Inside the inner cover will be the clutch actuation mechanism onto which the end of the clutch cable normally fits. This mechanism is quite simple, bolting to the inner cover with two setscrews. Watch the ball bearing at that end of the clutch actuation rod.

The gearbox sprocket is held by two setscrews and a special locking washer to the 5th gear, on the primary shaft, which spline passes through the crankcase. The sprocket can be held by wrapping the teeth with a piece of chain and locking that chain. Once the locking washer is removed the sprocket can be pulled off. Further to this the only other task which can be carried out without splitting the crankcase is the renewal of two oil seals which are behind the gearbox sprocket. The big seal often leaks. It can be easily picked out and replaced. Tap in a new, well oiled seal, as squarely as possible. »

The inner cover and its cjaiponents is easily replaced. The only thing to watch is that the alignment of the selector spi&dR is correct relative to the selector drum shaft. Have the gear trains in the proper neutral. You'll notice a line mark to the right of the end face of the selector drum shaft gear. Align the two marks on the side of the selector spindle directly adjacent to that line mark. See the diagram. You should do this before you finally tighten the inner cover. You should

Before you refit the selector drum you must align the two marks shown on this photograph. See the little nick on the spindle and the mark further down

The screwdriver is on the eccentric

Before you refit the selector drum you must align the two marks shown on this photograph. See the little nick on the spindle and the mark further down

The screwdriver is on the eccentric

The two arrows show alignment marks -wheel spina-e *>th drum aft selector

This second photograph shows the top lip of the shift foot which must click down on the little land on the selector shift in the previous photo. It's important that the shift foot's movement is equal up and down

Here the two tools are being used to make the up and The left foot gear change cross-over) works quite well, down movement of the selector arm equal. This is the Here's a Jarama sito» ing the lever and the block on Triple's arm - the Twins's is disimilar although the the crankcase on which the cross-over shaft bushes method is the same also check that the clutch actuation mechanism is fitted. You would be very wise to place a piece of rear drive chain around the gearbox sprocket before the inner cover is located for it is very difficult to place it there at any other point.

NOTE: Various gearbox sprockets are available. The best one for your machine is probably the one with which it was supplied. Laverda expect you to change the rear wheel sprocket rather than the gearbox one, because of the ease of fitment. The SFC has a cutaway inner cover to enable easy rear chain fitting and clutch cable installing without other removals. Its outer cover is in magnesium and features a quick-engine-filler. It cannot be fitted to a 'normal' Twin or Triple because the oil-filter neck will foul the gear lever.

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