Sealing Washers

[guzziart]

Hi,
I'm seekiing some technical advice on tightening composite sealing washers (aka Dowty washers, Bonded washers, Rubber Ring washers, etc.).  I guess the days of having a torque value for drain plugs that utilize an aluminum crushwasher is coming to an end.  Anyway, I go to do some oil changes on the v85 and find that the rear drive drain bolt sealed with composite type washer (vs sold skool aluminum).  Its ok though because my Guzzi parts supplier sent me 3 composite type washers to replace the existing drain plug sealing washers at engine, trans & r drive.  Since the composite sealing washers are steel with a rubber like inside diameter for sealing, I'm reluctant to torque the drain plugs to what the specs are for an aluminum crush washer.  To get the bike oiled and off the lift, I installed the drain plugs (M10's) with the new composite sealing washers to finger tight and then another 1/16 to 1/8 turn with a wrench (to kinda snug).
FWIW, I know how to tighten hardware to the first grunt, fart or just until it begins to leak again   So, any advice/rule of thumb on tightening these composite sealing washers is appreciated or am i over thinking something simple
Art

[Tom H]

You'll know you tightened it more than enough when it keeps spinning

I would finger tighten it until the bolt is seated. Then take my regular old Craftsman 3/8" ratchet and grasp it with my thumb and first finger on the "head" and the rest of my fingers down the handle. I do not grab the end of the handle in my fist. Then I would give it about a 1/4 turn or the like until it feels tight (such a damn subjective thing). Not much different than using the crush washers. The washer will do it's job, you just have to make sure the bolt doesn't fall out or over tighten and strip the threads, again like the crush washer.

Hope this helps,
Tom

[guzzisteve]

They usually leak, I use alu for best leak free results and you can torque.

[RinkRat II]

          THIS^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    Pitch 'em and put in the aluminum washers. worked long before composites. My $.02

     Paul B

[Antietam Classic Cycle]

I've been using cheap "Dowty" type washers purchased on Amazon for a while now and have never had a leak. In fact, they've stopped leaks where I've had them with aluminum crush washers. Previously, I was buying them from McMaster-Carr until the cost of them got a bit too high.

[guzziart]

Hey Charlie,
What are you tightening them down to or torque?  I'd hate to booger up the case by over tightening, I know I wouldnt tighten enough to pull case threads.
Thanks,
Art

[Antietam Classic Cycle]

Hey Charlie,
What are you tightening them down to or torque?  I'd hate to booger up the case by over tightening, I know I wouldnt tighten enough to pull case threads.
Thanks,
Art

I tighten by feel to "tight". I do make longer M10 level and drain plugs, the originals are way too short and it's easy to strip the threads.

[moto]

I tighten by feel to "tight". I do make longer M10 level and drain plugs, the originals are way too short and it's easy to strip the threads.

I stripped the transmission drain plug hole on my Griso and was surprised how easy it was to do. So I measured the depth of thread inside the case for both it and my T3. Here are the method and findings.



The original-seeming aluminum crush washers I have are 1 mm thick. On Amazon I found M10 Dowty washers of 2 mm and 2.9 mm thicknesses. So to fully engage the threads in the case, you would need drain plugs with these threaded lengths, depending on the washer used:

Griso/6-speed: 8mm for aluminum; 9-9.9 for Dowty

T3/5-speed: 9.5mm for aluminum; 10.5-11.4 for Dowty

[Tom H]

FWIW: You could go with a bolt (a standard bolt 13mm head will work) at least 5mm or maybe even 10mm longer than the threaded hole. There is clearance between the fully seated bolt with either washer and the gears on the 5 speeds.

Tom