oil pump plunger guide pin. 1955 g3lcs

[Duncan]

Arty, does it feel like the guide pin is engaging in the pump or tightening on the pump body its normally just that the pin is not going home properly as the pump can shift/slide down when the pin is removed?

Do the parts look factory or home made is the step in the pin slight or significant?

Are you able to measure the depth to confirm the pin is the correct length?

[arty]

Mick - thanks for the detailed advice, this is a first for me in the oil pump area of a Matchless.

Clive - the 'shouldered' end of the guide pin was pointed up and did actually return oil to the tank, although not very well, it was as a result of the P.O. saying he had replaced the pump and scrolling through old threads and members previous postings about the guide pin that I decided to check it out.

Duncan - none of the parts look home made but I am thinking of removing the plunger to check for any damage as a result of what I found with the guide pin.

Cheers Arty

[jack clegg]

I replaced the guide pin on my G80CS recently. Took it out to check for wear (2 thou worn, from rotating in the holder), replaced it for safe keeping with no problem. Got me a new one, took the old one out again, but when I went to replace it the thing fouled the pump body. Pump must have moved a little. Panicked for a minute. Laid on me back with a torch, I could see the pump groove slightly out of line. Managed to lever it with a probe back into centre. You could feel oil resistance/pressure when levering with the probe. Screwed back in perfect. Panic over.

[arty]

I took the oil pump plunger out and all seems ok with both that and the pin so will carefully reassemble as advised and fit new end plate gaskets, thanks again.
It will be interesting to see if the return is much better now the pin is in the right way!!
Cheers Arty