marine928

This morning on the way to work I stopped to fill up and my locking gas cap would not come off. The key would turn and I could go from "clicking lock" to no click free turn, but cap would not come out.
Tried all kinds of various key positions, key in, key out, pulling up on cap while turning.
Did a search but all that came up was dealing with a cap that would not lock. Any suggestions that do not involve cap destruction.

Thanks

Lon

Mrmerlin

drill a small hole on the flat part of the cap about 10MM from the edge of the lock cylinder,
only go through the first layer of plastic ,
then insert a drywall screw till it captures the next layer then remove the cap.
NOTE dont screw all the way through the second layer

marine928

Thanks Stan, 10mm from any side, also what function does the drywall screw perform.

Oh yeah, what can I do to remedy the situation?

thanks
Lon

curtisr

marine928

Gotta love youtube. Before I drill, I am going to try and get it off with a little patience after work. Will effect a repair if possible.

Thanks.

Lon

Mrmerlin

NOTE drill straight into the first layer,
the screw will grab the second layer and it should come off.

NOTE if you dont put a hole into the second layer then the cap can be used .

if you do put hole the second layer then the cap is done.

To fix the spinning you need to take the cap apart and replace the pawl ,
Jerry feather made a separation tool
Alan was involved with making/ distributing the pawls do a search

Alan

When it clicks - is it clicking as you spin clockwise or counter-clockwise?

The cap is designed to fail safe - it should fail to functionally unlocked (which paradoxically wrt the cap means the two parts (inner & outer) should be locked together for counter-clockwise movement and ratcheting for clockwise movement).

If the ratchet works normally it's hard to see how you can't then get it off. I suspect it may be ratcheting the wrong way now...?

Alan

928 DesMoines

The screw keeps the top layer (the outer plastic cap) engaged with the second layer so that it doesn't just spin when you turn it.

jpitman2

Not clear what occurs when you try to turn the cap anti-clock ? Locked, the outer should turn freely with no connection to inner; unlocked, it should unscrew the inner from the filler neck.

jp 83 Euro S AT 56k, creator of the pawls and tow hook tap.

FredR

Must say I was somewhat surprised to read of this specific failure mode. When mine failed first I noticed was that I could not lock the damm things but no problem removing them for petrol. The fix Stan suggested is logical as presumabably it keeps the inner part engaged on the dogs that facilitate the drive and the fact that there is a vid of how to do it suggests it is a common enough issue- yet another one.

Now the intereting question is whether we should keep some kit in the car to facilitate such intervention should it be needed when miles from anywhere at a petrol station and this suddenly happens- urrgh!

Rgds

Fred

Alan

No - because this absolutely is not the way they usually fail... Normally - as you describe - the failure is that the end of the pawl snaps off when it is pulled into the retracted position against the ratchet springs pressure. After breaking like this the major part of the pawl moves back to the extended position and locks one way (counter-clockwise for removal) and ratchets the other (clockwise to tighten - so you also can't over-tighten it).

So the two parts of the cap are locked together which means the cap is functionally unlocked - (think about that a bit).

It is unclear what is happening here - especially since it seems it is actually ratcheting in some way...

Alan

Jerry Feather

The Pawl mentioned is kind of U shaped with verticle teeth up the outer side of one branch of the U. The teeth mesh with the teeth in the cap which will lock the white-ish and red plastic together, but only in one direction. The teeth will ratchet in the other direction because of their respectiver "barb, effect.

In most of these caps the pawl is broken. When they break the other, back branch, of the U breaks off and then the off-center cam on the botton of the lock can no longer pull the pawl back from its engagement with the teeth in the cap.

As Alan says, that leaves the cap assembly in the teeth-engaged position (fail safe) so that it can still be opened, but the pawl can no longer be pulled back to lock the cap.

I have not seen a failure of the pawl so that the pawl will still move back and forward, but with the teeth ratcheting both ways, CW and CCW, which would mean that the teeth have worn so much that they are smooth enough in both directions to no longer lock the inner and outer pieces together. That is really the only way that the subject cap can have failed to allow for smooth turning in one key position and ratcheting in the other, but with no turning of the threaded inner part relative to the neck of the gas tank.

The only other way the PO's description of the "failure" to have occured is if he is trying to open the cap Clockwise rather than Counter Clockwise.

In regard to the ratcheting of the cap when installed, my advise is to ratchet it no more than about two clicks because of the potential for wear on the teeth; or no more than enough to set the red part horizontal in those cases where the cap will otherwise interfere with the outer lid when not horizontal.

If the teeth are ratcheting both directions, follow what Stan has advised.

Jerry Feather

To the OP; did you ever get the cap off, and what did you discover was the problem?

mclarenno9

Nothing to see here...

Alan

Not sure what I am looking at there... It doesn't look like any 928 cap I have seen....? Is this a different early version? I also didn't recognize the one pictured above.

Alan