This 818.630 5-speed gearbox – with all of its grit and grime – is fresh from a 1970 Lancia Fulvia 1,3S we have done a tone of work on. The box shifts well and runs relatively quiet. But, it does not enjoy going into second gear. In fact, it practically won’t go in at all under load.
I had to do a bit of digging in the toolbox to find the right toothed-sockets, and then modify a few. Lancia seems to have had an aversion to a traditional hex-head fastener. Different tools are also required for Series 1 and Series 2/3 cars.
Here is the main cluster (minus 5th gear and 4/5th synchronizer assembly). The gear stack lives on the main pinion shaft. For those that are interested, gear order from the pinion gear to tail is; reverse, 1st, 2nd, 3rd, 4th, and 5th.
Tearing down the gear cluster revealed a few things. The most concerning was a (very) loose pinion nut, followed by worn engagement teeth on first and second gear.
The Kristick’s Lancia Spares came through, yet again, and were able to supply two synchronizer rings, as well as, a new-old-stock selector ring and 1st gear.
I was also lucky enough to source a NOS 2nd gear. But, it was missing a number of details and required additional grinding and machine work. I am running the tool post grinder above to open up the internal diameter to match the 2/3rd synchronizer hub.
We also had to add the oil grooves – as they were entirely absent. This required some …creative… setup. But, the resulting oil grooves turned out really well.
Adding two oil feed holes to the gear.
Here is re-ground gear sporting a new pair of oil grooves and oil feed holes. The last thousandths will be honed out in order to get an appropriate surface finished,
Finalizing the internal fit and surface finish.
The transaxle all cleaned up and going back together.
Such a great unit – like most things Lancia. Everything checked out on the bench. So, with the synchronizers lapped to spec, two new gears, a re-torqued pinion nut, reset pinion-to-ring contact, and thorough cleaning – the gearbox is going back together with my preferred case sealant, Loctite 518.