A "spanner"-ish question about spark plugs

[Al115]

Not quite, more a "socket"-ish question (but it didn't sound as appropriate!)

Can anyone please tell me what fitment I will need to remove/refit the spark plugs in my V70. I already have the torque wrench - not sure what size socket I will need for the plugs though?

Apologies for the "dunce" question!


Alastair

Alastair,

I don't think it's a dunce question but this may very well be a dunce answer.

I've never fully understood the whole spark plug socket thing. As far as I'm aware there are two fitments - 10mm and 14mm. I use the 10mm one on my 850. However, I don't understand how it can possibly be classed as a 10mm socket because the hex is clearly larger than 10mm. Weird. The socket if definately stamped 10mm on the side though.

If you're buying a socket make sure you get one with the rubber insert so that the plug is held in the socket thus making it easier to extract the plug from the chamber.

Can anyone explain why my socket is stamped with 10mm even though it is obviously bigger than this?

Regards

Andy

[warthog]

Andy,

the 10mm designation for the plugs relate to the thread size. The socket required is actually a 5/8" AF deep socket, which for the 850's will need to be 3/8" drive as there is not much room available down the recesses in the head for a 1/2" drive socket.

(for information the 'standard' 14mm spark plug use a 13/16" AF socket!)

Cheers

[Al115]

Brian - thanks for the information. AF eh... I was wondering!


Alastair

Just to confuse things I use a socket with a 1/2" drive with no problems...

:-)

Roger

[Chris_Rogers]

A 5/8 inch AF spark plug socket is required.
Choose the drive size to match your socket set.
I have both 3/8" and 1/2" drive size and find the 3/8" easier. Do use a torque wrench. I also put a smear of copper grease in the plug threads to aid removal.
The 10mm bit comes from the thread size of the spark plug