365 Gearbox Drain Plug

[Dilkris]

What is the thread in the casing of a 365 gearbox box for the drain plug.?
My existing tapered plug plus magnet goes tight after maybe 2 turns and to me, it just does not feel right. (I don't know if I have your typical metric/imperial bodge from po's)
Both thread patterns indicate a threads pitch in the order of 1.25 and I believe, (although difficult to measure accurately), the thread in the casing is 16mm.
Is this correct? Any ideas where I can get the correct plug? 

In hindsight - (added later) - I suspect this is a national pipe thread (npt) - am I correct?? 
 

[BDA]

Does your existing plug have a square drive? If not, you may have a replacement that almost fits. I would think r.d. or DBE sell the proper plugs.

[Dilkris]

Yes it does - square drive (10/11mm) - tapered thread (of some unknown kind) and magnet on the end. It most certainly is a sump plug - whether it is a sump plug for the 365 gearbox is questionable.   

[Pfreen]

I just changed the oil in my 365 transmission and I think you have the correct drain plug.  It tightens after about two turns, has a magnet and a square metric drive.

  Does yours leak?

[Dilkris]

I don't know, I have just finished rebuilding the box. The fact that it is tight at 2 turns doesn't seem right, there are so many threads left exposed on the plug, but reading your post - maybe this is normal. 

[BDA]

I'm sure Pfreen is correct. It has been a long time since I checked my tranny oil so I wasn't sure. I think the drive is 11mm. If you don't have one, you should get an 8 pt. socket for it. Surprisingly, they are pretty readily available in metric sizes. I didn't think so so I filed mine to accept a 3/8" 8 point socket - measure first!

[jbcollier]

7/16" = 11.1mm

An imperial 7/16" square socket works well and may be easier to find in some areas.

[jbcollier]

Duh, I think it's actually 10mm!

[Kendo]

Mine is 10mm. And my only Snap-On tool is a square drive socket I got for it. (Guy a work had access to a Snap-On dealer)