A new OEM oil drain plug crush washer design?

[Kane]

Changing my oil today, I noticed that the new OEM crush washer for the 17mm drain plug, P/N GU10528900, does not have the nifty little rubber gasket in the center of the washer like the one coming off of the bike. I guess Piaggio is saving money by omitting the rubber center (while charging $5.25 for the washer ). That rubber center gasket is such a good idea! Hmmmmm. What’s up with that?!? I gave it a few good tugs with a 6” socket wrench to seal it. Hopefully it will be as leak-free is the cool rubberized old style.

old style is on the left, new style is on the right:

[gstallons]

Mmmm , you may be able to go to a tradition (as in old) auto parts store and have them find you something .

[80CX100]

Those washers go by a couple of different names, iirc "Dowty" being one of them.

I can't remember where I got my supply, Amazon, MGCycle or the local hydraulic supply shop? fwiw.

At $5 each, I'd be sourcing the good ones locally.

[Kane]

Well I found this:

https://www.mgcycle.com/index.php?main_page=product_info&cPath=34&products_id=52
 

That must have been what was there before, rather than the current OEM as mentioned. I guess either will work, but the rubberized one at MG Cycle is less expensive if nothing else.

[80CX100]

I started using those Dowty washers on any plugs that had a tendency to leak or weep oil, ie sump, tranny, diff, but especially the fork drain plugs; they solve a lot of niggly leak problems, fwiw.

[wdietz186]

Those Dowty washers are great, especially on fittings with pressure behind them. For drain plugs they are a bit of overkill in my opinion. Use of aluminum or copper sealing washers is perfectly fine if you remember they are really only meant to be used once. When you tighten the plug the soft metal conforms to the surfaces of the plug and its seat forming a good seal. The downside to the compression of the washer is the metal work hardens and if reused it requires more torque to make the seal and this will often lead to distortion and weakening of the threads causing them to strip eventually. Aluminum washers are considered to be one use items but copper can be reused if annealed to soften it so it conforms again as long as it hasn't been deformed too much by the previous use.

[po18guy]

Flip the aluminum washer over next time and use a thin coat of wheel bearing grease on both sides. Never had a leak.

[guzziart]

I've been buying my crush washers from McMaster-Carr for most of my stuff (bikes & cars). 

[Chuck]

^^^^^^I just received an order of 6061 T6 aluminum from McMaster-Carr aircraft supply.

[docc]

2 hours ago, guzziart said:

I've been buying my crush washers from McMaster-Carr for most of my stuff (bikes & cars). 

I immediately went looking at McMaster-Carr for the "Dowty" (bonded seal) washer, but couldn't find it there . . .

[LowRyter]

and why is this special crush washer needed?   It just looks like another point of failure.

[docc]

A bonded seal washer doesn’t require the torque to “crush” a crush washer ( although it does take much), so will be easier on the sump threads over time. My Sport is still on its original seal washers.

[Chuck]

How about these?

https://www.mcmaster.com/sealing-washers/metal-bonded-sealing-washers-6/

[footgoose]

On 1/18/2021 at 11:56 PM, Kane said:

Well I found this:

https://www.mgcycle.com/index.php?main_page=product_info&cPath=34&products_id=52
 

That must have been what was there before, rather than the current OEM as mentioned. I guess either will work, but the rubberized one at MG Cycle is less expensive if nothing else.

Interesting MGcycles calling that a 10528930 and 10mm, when our drain plugs are 10mm and the called for washer is a 10528900

[footgoose]

looks like oem was likely the one w/o rubber