Technical 500F Gearbox question

[TOBYOLIVIA]

Ciao a tutti!

Done some looking and reckon this is the best forum to be on so looking forward to it.

We have a 1969 Fiat 500F and I've just rebuilt engine and doing gearbox as we speak. I have a new rear part of the gearbox (the most forward part when in the car if you see what I mean) as other had worn the round hole to an oval where gear selector shaft goes in.

Anyway, I've received the new casing but it has an extra threaded hole and I don't know what it is for. It is not the selector shaft and it is not the speedo drive.
See picture and the hole I am pointing to.

Looked around 'net and it looks like it should be for some sort of sensor or something. Any clues?

Help much appreciated.

Ciao

Toby

 

[Vitesse]

Total guess but it is more than likely a part for a later Fiat 126, so is most probably where a switch goes for the reverse gear light?

Tony

 

[Damon500]

Totally correct- this is a late 126 end housing with reversing light switch mounting.
You can either get a reversing light switch to fill the hole or use a correctly sized bolt and washer with some sealant to blank it off. Just make sure if you use a bolt that you don't use a long one or you won't be able to select reverse!

 

[TOBYOLIVIA]

Thank you for your help everyone.