Oil Drain Plug Washer

On my 2016 Bonneville T100, I’m on my 2nd oil change (yes, very low miles!). I note that the drain plug is naked – no washer at all. When it’s tightened, it’s metal to metal !! Did I lose it or is this “stock”. In all automobile engines I’ve worked with all my life, there has ALWAYS been some kind of washer, e.g., a flat copper one, possibly an aluminum one, or perhaps a crush washer of some kind.


If this is “stock” (i.e., as factory intended), is anyone as surprised as I am?


I note this thread:

https://www.thetriumphforum.com/threads/street-twin-oil-drain-plug-alum-washer.25141/

which talks about an aluminum washer of dimensions 14.5mm x 3mm x 23mm


This thread:

https://www.thetriumphforum.com/threads/oil-drain-plug-crush-ring.32603/

posted this picture of a factory washer, which is kinda what I had in mid.




I'm not having a serious leak problem; it just doesnlt seem copasetic.

 

Thanks Triple X - you just validated my concern. I have no idea how it could have gone missing as I only changed my oil once before. Anyway, I will chase down that AL washer !!

 

You make an interesting point, ADIE P. You forced me down onto the floor with a flashlight to take a closer look. At the end of the threaded boss into which the plug threads, I see a tiny sliver of AL that extends beyond the (black) painted part. At first, I thought this tiny sliver might be the washer but it woudn't pry off using a sharp knife. Also (1) tapping with a small hammer on the sharp knife, it didn't want to come off, and (2) it's only about 0.025" in thickness - nothing like the factory washer that is nominally 3mm (0.118") thick.

With all this said, I'm pretty sure "that the aluminium crush washer ISN'T stuck to the face of the drain hole". The washer that's supposed to be there vanished.

 

Problem solved !! For all of you Bonneville owners (especialy those who live in the US) who may have somehow lost your oil drain plug washer, here's the cheap solution:

Dorman makes a 4-pack of aluminum washers for oil drain plugs:
Dorman 097-832CD; I.D. = 14mm; O.D. = 0.950" (24mm); thickness = 0.075" (1.9mm)

O'Reilly Auto Parts sells the box for $4.39

 

P.S.

A lot of this information/discussion is in this thread from 2020, which I participated on:

https://www.thetriumphforum.com/threads/street-twin-oil-drain-plug-alum-washer.25141/

 

Ha !! I had to post back. Guess what?
I found the stock (aluminum) oil drain plug washer !!!

And guess where it turned up?

In the bottom of the drain oil pan, of course. I found it when I transferred the oil to a recycle jug. And interestingly, it's virtually identical in all measurements to the Dorman washers I mentioned above !!

I'll be more careful next time ...