Is there an alternative locking gas cap that fits the 928 (1987)? Mine appears to be pinned so that turning the key does not lock the cap. Before I spend the ~$115 on a new cap, I thought I'd see if there are more reasonably priced alternatives. I don't care about original looks, just function.

 

may just be that the lock/unlock pawl has broken in your current cap If that's the case Jerry may still have some metal ones ha made as a replacement for the original plastic one. Check out this thread.

 

Yes, Jerry does have very many of the new aluminum Pawls I made some time ago. I made just over 500 of them and probably still have well over 450. They are now $30 shipped to domestic locations. The 928 gas cap is unique to the 928 and I think worldwide. Send me a PM.
Edit: But you need to be sure that your cap is the later version with the longer center "snout" since that Pawl is different from the earlier ones with the shorter center "snout." I don't think they are interchangable.
Edit again: Oh, I see yours is 87. My Pawl will work in it.

 

By the way, the 928 gas cap it kind of unique in that to secure it by turning the key that actually "unlocks" it by pulling the ratcheting Pawl back from the ratchet teeth so that the outer red part turns freely both ways from the threaded whitish part. Thereby it cannot be removed by unscrewing it. When the pawl fails the piece that allows it to be pulled back breaks off so it fails in the functional mode but cannot be "unlocked" to secure it. Does that make sense? Ordinarily to lock something something is put in place to block something else from moving. It is just the opposite with the 928 gas cap.

 

With a classic sports car that is typically rarely used, or unless you live in a bad area and park outside, or park in bad areas, why would you worry about a locked gas cap? I just don't understand that, or locking wheel nuts. I never, ever hear of somebody having their gas or wheels stolen.

 

Ed, some guys just hate having things that are broken or don't function correctly.

 

I am in that category. The PO disabled the intensive washer system on my car and it always bugged me. Though I would never use it, I want it to be operational.

 

And some of us just hate the idea of having something stolen from us, no matter how remote the possibility. Maybe 'cause we grew up with brothers or maybe 'cause of that little **** that borrowed my hot wheels on the day he was moving and told me he left them on the street corner (they weren't there).

 

And Jerry's pawl works great. Such a simple part that fits better than the factory part. And much stronger. Just one of those things that adds to the vehicle originality.

 

+1 on the above. Jerry's pawl is the best "928 aftermarket fix" since sliced bread, plus your gas cap continues to lock / unlock with the the original key. Same goes for the ABS spare tire cover he makes if yours is broken.

 

With what's happening and going to continue to happen, more people may be locking their gas caps again! I won't be one of them as I'm in Ed's camp on wheel locks and locking gas caps. The only people those things usually deter are the owners.

 

To answer my own question, it looks like caps for some Class 7 diesel vehicles may have the same size and pitch threads. None of my diesel vehicles that have external threads on the filler tubes have the right size, though. They are either much too large, or too small. There are caps available that look to be the right size for as cheap as $35, but the decent ones are more like $80. There are vented, non-vented, locking and non-locking available. They are also all metal, not plastic. I suspect that there are some passenger cars out there with the same external threads on the filler tube, but I couldn't find any with casual searching. It seems unlikely that Porsche created an entirely new thread size and pitch that was never used on anything other than the 928. Possible, though.

Eventually I may have a convenient opportunity to test fit different caps.

For now, I ordered a couple of replacement pawls made out of plastic.

 

The new pawls arrived today (~2 weeks from order to arrival). Well made, perfect fit. My gas cap's locking function has been restored.

Here is where I ordered them from (they have them for both style gas gaps, early/late): https://en.928-944parts.com/products...p-reparatieset

I found it easiest to email them to place the order since you can't select the USA as a destination on their website: p@928-944parts.com

There is no VAT for export to the USA, so it's just 10 euros in shipping on top of the parts price. Payment via PayPal.

They have a video on how to change the pawl:
But, a couple of notes to make it easier:

1) When you remove the main inner cap from the red outer shroud, start by working on the two tabs that are closest to the protruding long piece that you use to turn the cap. Those two tabs are nearest to the stiffest parts of the shroud. If you do one of them last, there won't be enough flex left in the shroud to get the tab to release. Once the first two are released, the third tab is in the middle of the side and has a lot more flex. That sequence will enable the main section to come out of the red shroud pretty easily.

2) The two "feet" of the U-shaped lock wire can be pushed up from below, rather than digging at the lock wire to get it out from the top. Once you push in the feet a little, the top can be easily grabbed and pulled out.

3) Don't forget to dig out any broken pieces from the old plastic pawl. They can blend in with the surrounding white plastic, but they've got to be in there somewhere.

4) When reassembling, the main white section does have locating tabs and only seats fully in the red shroud when those tabs line up with the slots on the shroud.

Easy ordering process, friendly and responsive person to deal with, reasonable price, easy to replace.

 

Send your gas cap and key to Jerry, and in two weeks you'll get both back in perfect working condition without having to worry about having the right tools to disassemble or reassemble anything.

Why would you order something from some company in the Netherlands when Jerry is local, cheaper, has created special tools for the cap disassembly and reassembly (so you don't have to molest it by prying it open with various screwdrivers), and has a higher quality product machined from aluminum (not 3D printed from some plastic that will again fail in a couple of years)?

 

The right tools? A screw driver? That's all it took Hardly "molesting" it any more than any other method of disassembly. You can't disassemble it without flexing the outer shroud locking tabs over the center section.

3D printing has come a long way. These pawls are not cheap homebrew plastic with obvious string patterns and only good for test fitment. These are high quality.

I prefer a plastic pawl so that it is less likely to wear down the plastic of the gas cap every time you click it when screwing the cap on. Pawls are replaceable, the rest of the cap, not so much. It takes less than 5 minutes to replace, and I have a spare pawl now. I didn't have to be without my gas cap and a key for two weeks.

Jerry has also made some very mean, unfounded and uncalled for comments about me in other threads. So, I spent my money elsewhere. It's good to have options.