Author Topic: Lancia locking fuel cap  (Read 77 times)

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Offline lancialulu

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Lancia locking fuel cap
« on: April 28, 2026, 03:53:12 PM »
Has anyone a clue on how to dismantle this locking fuel cap supplied by Lancia (door key operated).

Thanks

Offline peteracs

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Re: Lancia locking fuel cap
« Reply #1 on: April 28, 2026, 05:24:17 PM »
Hi Tim

Sorry that is the only Beta lock I have not had to take to pieces…

Peter
Beta Spyder S2 pre F/L 1600
Beta HPE S2 pre F/L 1600

Offline lancialulu

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Re: Lancia locking fuel cap
« Reply #2 on: April 28, 2026, 05:39:48 PM »
Hi Tim

Sorry that is the only Beta lock I have not had to take to pieces…

Peter

I do not want to but on the GNW rally at the first and subsequent fuel stops it refused to unlock just spinning around and after generally 10 minutes I could find a spot where it would catch and undo so I need to sort it. In the meantime I have swapped caps from another car that works but is not Lancia... (I think Fiat)

Online Nigel

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Re: Lancia locking fuel cap
« Reply #3 on: April 28, 2026, 06:06:20 PM »
Has anyone a clue on how to dismantle this locking fuel cap supplied by Lancia (door key operated).

Thanks

Tim,
On the underside you'll see a gold coloured ring with notches. This ring turns to
lock/unlock, about 25/30 degrees I think, unremembered direction.
Beneath that is a sliding bar which interacts with the rotation of the key. This bar has a
tiny spring keeping it in the 'locked' position. Turning the key compresses this spring.
It is likely that the spring has broken or is gummed up with debris causing it to remain
in the unlocked central position.
The pics show (not necessarily in order!) the bar, the hole where the bar spring goes, the pin
at the end of the key barrel which moves the bar, and inside the central cap the 4 'dogs' that
interact with the bar.
There's also a wavey washer that sits on top of the sliding bar.
Quite a fiddly operation, the spring when good is likely to fly off into the adjacent postcode.
Yep, this one did.
Edited to add: there is probably a tiny lug that goes in the end of the spring, unrecalled detail.
« Last Edit: April 28, 2026, 06:11:15 PM by Nigel »
1984 2.0 Carb HPE [ex Aus] Grigio Finanza.
2007 Mazda 6 2.3 [current daily, highly recommended]
The past:
1980 2.0 HPE White in South Africa [hope it survives!]
1976 1.6 Coupe Lancia Blu [PFG 76R] [probably deceased]
oh,and an Uno Turbo 1997 also in SA [stolen,never recovered]

Offline lancialulu

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Re: Lancia locking fuel cap
« Reply #4 on: April 28, 2026, 06:34:59 PM »
Nigel

Many thanks. This goes a long way! But can you explain how to separate the metal bit from the plastic?

Tim

Online Nigel

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Re: Lancia locking fuel cap
« Reply #5 on: April 28, 2026, 08:36:29 PM »
"On the underside you'll see a gold coloured ring with notches. This ring turns to
lock/unlock, about 25/30 degrees I think, unremembered direction."

I think I clamped it in a soft jaws vice and tapped it around with
a small pin punch. Looking at the plastic rim I don't think direction is vital,
but anti-clock probably wise. The gold ring wasn't with these parts so no sure what
happened to it.

N.
1984 2.0 Carb HPE [ex Aus] Grigio Finanza.
2007 Mazda 6 2.3 [current daily, highly recommended]
The past:
1980 2.0 HPE White in South Africa [hope it survives!]
1976 1.6 Coupe Lancia Blu [PFG 76R] [probably deceased]
oh,and an Uno Turbo 1997 also in SA [stolen,never recovered]

Offline lancialulu

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Re: Lancia locking fuel cap
« Reply #6 on: May 03, 2026, 09:35:05 AM »
Sunday morning distraction. Nigel you inspired me to take the lock apart!

I found one mangled spring and a bit of plastic which I have identified as the "tab" to stop the spring from getting mangled.

Luckily I just had a replacement spring amongst my spring collection same weight diameter and length....

Now I just need to figure out how to replace the "tab".....

Any ideas (apart from 3D printing the plastic bit of the cap...??

Offline lancialulu

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Re: Lancia locking fuel cap
« Reply #7 on: May 03, 2026, 09:37:26 AM »
Not sure why second photo is squashed?? I resized it and it looked fine on my PC

Offline lancialulu

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Re: Lancia locking fuel cap
« Reply #8 on: May 03, 2026, 10:34:16 AM »
Close off this thread - Drill a 1.5mm hole in centre of plastic rim where tab was, flatten 1.5mm soft steel nail, cut to size, insert and ensure slider can pass over it. Grease and reassemble. Job done.

Happy Sundays!
« Last Edit: May 03, 2026, 10:38:53 AM by lancialulu »

Online Nigel

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Re: Lancia locking fuel cap
« Reply #9 on: May 03, 2026, 10:36:44 AM »
If I'm thinking correctly Tim, what you need
is a "flat-headed shortened nail" looking device, the shaft of which goes
into the end of the spring. It needs to fit the inside of the spring fairly well,
so that it can't rock around. And the "head" needs to be no bigger than the
bar.
If that description is valid, I'd make something from an existing something.
Brass would be my go to as its easy to work.
A screw, reduced in size with a drilling machine and a file may work.

Edit! Your work-around has worked, brilliant,

Nigel
« Last Edit: May 03, 2026, 10:38:24 AM by Nigel »
1984 2.0 Carb HPE [ex Aus] Grigio Finanza.
2007 Mazda 6 2.3 [current daily, highly recommended]
The past:
1980 2.0 HPE White in South Africa [hope it survives!]
1976 1.6 Coupe Lancia Blu [PFG 76R] [probably deceased]
oh,and an Uno Turbo 1997 also in SA [stolen,never recovered]