Model 14 Oil filter cap- Wrong thread!?

[simonkgk_LAPSED]

Rebuilding 2 Model 14s - 1959 and 1960.

I bought new Oil filter components and Caps from the AMOC shop but the thread seems to be wrong.

The original cap screws in and out fine so it isn't a fault in the engine casing.

Is this an instance that later bikes ran a different thread ( and so I need a different part ? )

Can anyone help?

Simon

[ajscomboman]

I'll check the stock tomorrow when I'm there and let you know if there is an issue.

[ajscomboman]

As promised, I have checked the caps and the thread is correct. The cap is the same thread as the 1 1/4" fork stanchions. All of them screw straight in. There was a crankcase on the secondhand shelf stock and it screwed so far by hand and got tight, however its the threads on the case that are tight. Once it was wound in and out the case was fine.

[simonkgk_LAPSED]

Thanks for response.

But... the original cap threads in and out happily. The New cap one tightens up after a turn exactly as though it is a different thread.
I had tried the 'its just a bit tight it'll sort itself out ' method but the thread jammed up half way in and then stripped out on getting the cap back out.
So there is definitely something awry. ( fortunately I have a spare crankcase )

Both my bikes are /60 crank cases. IS it possible that there was a change of thread on later bikes?

Simon

[ajscomboman]

Thanks for response.

But... the original cap threads in and out happily. The New cap one tightens up after a turn exactly as though it is a different thread.
I had tried the 'its just a bit tight it'll sort itself out ' method but the thread jammed up half way in and then stripped out on getting the cap back out.
So there is definitely something awry. ( fortunately I have a spare crankcase )

Both my bikes are /60 crank cases. IS it possible that there was a change of thread on later bikes?

Simon

Not that I'm aware of. I tried at least 12 caps in the crankcase and they all screwed in by hand over half way and then got a little tight but not enough to strip out the thread. They easily went straight home on the stanchions. We do have an unfinished end cap that has a thread cut but not a filter attached. I assume that it more than likely came from Andrew Engineering but the thread was very very loose on the stanchions, enough to rattle side to side but screwed into the crankcase using only fingers and I'd say it was too loose and could easily strip the threads if tightened down hard. As the club supplier makes the same part for both applications using the same thread cutting settings I can't really ask him to split the machining. You're more than welcome to send it back and try another.

[ajscomboman]

Thanks for response.

But... the original cap threads in and out happily. The New cap one tightens up after a turn exactly as though it is a different thread.
I had tried the 'its just a bit tight it'll sort itself out ' method but the thread jammed up half way in and then stripped out on getting the cap back out.
So there is definitely something awry. ( fortunately I have a spare crankcase )

Both my bikes are /60 crank cases. IS it possible that there was a change of thread on later bikes?

Simon

Not that I'm aware of. I tried at least 12 caps in the crankcase and they all screwed in by hand over half way and then got a little tight but not enough to strip out the thread. They easily went straight home on the stanchions. We do have an unfinished end cap that has a thread cut but not a filter attached. I assume that it more than likely came from Andrew Engineering but the thread was very very loose on the stanchions, enough to rattle side to side but screwed into the crankcase using only fingers and I'd say it was too loose and could easily strip the threads if tightened down hard. As the club supplier makes the same part for both applications using the same thread cutting settings I can't really ask him to split the machining. You're more than welcome to send it back and try another.

[ajscomboman]

I'll down load a picture showing the caps screwed home into both parts.

[Mick D]

Hi

Why not try to mesh the threads of the old and new caps, this will indicate whether it's a 'TPI', thread form or diameter issue.

Regards Mick