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Drain plug primary drive case

Posted: Sat Aug 18, 2018 12:48 am
by alan.moore
Whilst continuing to get to know the WNG I found the word DRAIN stamped into the outer primary case just above one of the case securing screw holes. Inside at this point the gasket face is relieved so that when that screw is removed the oil can run out of the screw hole. Per the parts lists for WNG and civilian singles the part numbers, and casting numbers, are the same but clearly the WNG ones were modified to allow the oil to be changed without having to remove the clutch and separate the cases.

If you look closely at the relieved area you can see the casting marks so it does not look like it was a case of a chap grinding that area away to modify a standard case but that the case mould was actually altered to produce the relieved area.


However, in my mind it looks like a prime place for a leak if the screw does not fully seal against the countersunk area in the case hole.

SDC11558.JPG
Drain point


SDC11559.JPG
inside of case


Cheers
Alan

Re: Drain plug primary drive case

Posted: Sat Aug 18, 2018 3:05 am
by nevhunter
Checked two I have here. Both are rough cast and genuine therefore. No sign of the relief or the "DRAIN" stamp. That doesn't mean it's not genuine in your case . Nev

Re: Drain plug primary drive case

Posted: Sat Aug 18, 2018 7:40 am
by simon.holyfield
Have a look at the oil tank drain plug, Alan.

http://ariel-square-four.blogspot.com/2 ... r.html?m=0

Is yours stamped like this?

Re: Drain plug primary drive case

Posted: Sat Aug 18, 2018 1:57 pm
by alan.moore
simon.holyfield wrote:Have a look at the oil tank drain plug, Alan.

http://ariel-square-four.blogspot.com/2 ... r.html?m=0

Is yours stamped like this?


Funnily enough the one on the WNG looks like a replacement but the one on my VH (which was XWD) and has the smaller oil tank does have one with the DRAIN HERE on it. Also has the brass screw cap and chain as per the WNG so I think the VH tank is from a WNG.

The DRAIN on the primary certainly looks factory because the relief above the screw hole is part of the casting rather than having been ground out.

Cheers
Alan