Jerry Feather

JS, it does not fail the other way. When the top rear finger of the ratcheting pawl breaks off, as you can see with the broken pawl I returned with your cap, the pawl can no longer be pulled back from ratcheting, so it will always ratchet upon closing and lock together to be removed. The reason it spins freely when secured is because the pawl is no longer engaged with the teeth in the white part of the cap when it is pulled back with the key.

You do not need to be prepared for another failure because it will not fail in the secure position, and I am pretty sure that there is nothing that can be done to the cap that will break the aluminum pawl I put in it. Your next failure is going to be a break in the red or white plastic or possibly wearing the plastic teeth out of the white part with too much ratcheting with the metal pawl. I do put some fresh grease in the teeth when I put these back together to minimize the wear.

Jeff Bowlsby

The cap from my 1981. I have no doubt that it is original to my car.

Jerry Feather

It's nice and white, and it looks like the early style, but it would be nice to see the inside at more of an angle so I can see the length of the center compared to the rim. In either case I think I can fix it.

Jeff Bowlsby

Here is side shot. Auto focus on my iPhone took over...hope this is helpful, best I can do. It will be on its way to you tomorrow. Very much appreciate you doing this for me, let me me know the details of what I owe you after you have seen it. Having trouble posting a photo(?) Will keep trying.

Jeff Bowlsby

Jerry Feather

OK, It's the early cap. Send it over.

Randy V

JF - can you explain why the later cap has a longer center section?

What is the purpose?

The early style fits the later model cars.

Randy V

JF - can you explain why the later cap has a longer center section?

What is the purpose?

The early style fits the later model cars.

Any idea what model year started to use the long center cap?

SwayBar

I had no idea a thread on gas caps would be interesting.

Nice job JF!

Jerry Feather

I don't know for sure, Randy, but I think it has to do with the longer key. Then, I don't know much about that either such as when it started. Either cap will fit any 928, I am pretty sure.

Randy V

Yeah, that's what we were thinking as well, but the longer alarm key fits in either version.

Jerry Feather

Then perhaps it has to do with the redesign of the pawl. The later version that I have replicated in aluminum is a bit taller than the early version. Even then, however, the difference in height of the pawl is not as great as the difference in length of the center of the caps.

Mrmerlin

the longer cap center is for the alarm key .
My 88 S4 didnt have an alarm and thus came the fuel cap came with a short center to match the short key.
My 85 had a alarm and thus had a longer center on the cap so the long key fits.

Jerry Feather

Fine, Stan, but Randy just said that the long key will also fit the short cap.

Alan

I'd think it very unlikely that a long key could work in a short cap, however I'd expect a short key could work on a long cap. Its largely irrelevant for stock considerations as I believe there were only a few years where both short & long keys were provided - and I assume any car delivered with a long key would also have a long locking cap to match?

The long key has the alarm section at the tip end - the business end for the main lock is the part nearer the key head - so the longer caps must just a have dead space after the lock tumblers to account for the longer key. If you put a long key in a short cap it just won't go in far enough to engage the tumblers correctly.

Alan