Crush washer / oil drain bolt

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Hope I didn't miss this in my search . . .

Figured I'd replace the oil drain bolt crush washer with an oil change this eve and am not sure which side of the new washer is up. Is it the rounded/fat side toward the pan or down toward the bolt head? Can't really tell from the old crushed washer but I'm figuring fat side up squishes into the nooks when torqued to seal as need be.

TIA,

Lincoln . . .

 
I've reused the washer on both the engine and rear oil drain bolts 3 or 4 times now with no leaks.

I think the owners manual says to replace it if it's damaged.

When you put a new one on it's a little tricky, because you have to tighten it enough to crush it without stripping it. It is very easy to over tighten.

 
Copper definately! Reusable with no controversy as to which side is up.

I don't understand why there is an up when it just gets sandwiched between two surfaces. What's the difference? Theyre both flat surfaces.

 
If its torqued right, it will seal in either orientation.

Copper is OK and reusable, but you're trying to crush it like a gasket too, and it does plastically deform and become more brittle with the work hardening.

Its a small price to use fresh crush washers.

 
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I was doing some reading on this the other day and google brought me right back here. I won't say to use the Search feature because I hate people telling me to - I like a fresh discussion on old topics occasionally.

One comment that really sticks in my mind though. At least one person said that he didn't use one. But, once you remove the drain plug, at first glance it may look like there is none because it's been completely crushed and looks to just be a part of the drain bolt. I usually have to pry it off with a dental pick.

Here is some previous discussion and there were some very interesting comments among the usual blather.

Crush washers

I usually buy 3-4 filters at a time and get an equal number of crush washers. These are our babies and trying to save nickels & dimes on two buck parts just isn't worth it to me, no matter how over priced they appear.

 
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I've answered this in other threads. The crush washer has a hard flat surface and the softer crushable surface. The flat hard surface goes toward the engine proper (as this surface is milled flat at the factory). Now since the oil drain bolt is forged it is not (or may not) be perfectly flat. This is where the crushable side of the washer deforms to then match any imperfections and create the seal.

And, as per the service manual; if the old washer is not damaged, it can be reused.

Nothing wrong with changing it over to a copper washer but that isn't significantly better either.

 
As I mentioned in the earlier referenced thread from last winter, I have been using these soft metal washers (looks like brass) that also have a hard rubber seal on the outer circumference. I started using them years ago on my SAAB autos, but noticed they fit the Feejer drain plug perfectly. One of these should last the life of the bike.

md_3330417f-ce66-475b-95b2-e63103137d7e.jpg


I get mine here: https://www.eeuroparts.com and just add a few to any orders I have going in. They are the best SAAB parts place I've ever found online. And they even have free shipping over $49, so you'd only have to buy 36 of these drain plug washers to qualify!! :blink:

 
I've answered this in other threads. The crush washer has a hard flat surface and the softer crushable surface. The flat hard surface goes toward the engine proper (as this surface is milled flat at the factory). Now since the oil drain bolt is forged it is not (or may not) be perfectly flat. This is where the crushable side of the washer deforms to then match any imperfections and create the seal.
I guarantee you that the distribution of orientations in the field is close to even. Have you seen the jokers that they hire to do the oil changes? And how many people that have installed them themselves have actually thought about it?

I also guarantee you that regardless of the orientation, the whole thing crushes and redistributes plastically under the 31 foot pounds of torque that I seem to remember is spec'ed. The pot metal they make these things out of is NOT as hard to crush as a copper washer. In fact, if you use a copper washer, you probably should be changing your torque spec since it will affect the stiffness of the connection.

I will also guarantee you that the back side of the head on bolts of this caliber is plenty flat. If it weren't and you were actually counting on a crush washer or a copper washer to seal it, you'd be screwed....

Hey on the SAAB washers, which appear to also work fine, maybe someone can get 36 of his closest friends together and buy 49 of them with free shipping. :rolleyes:

 
It's only November 6th and we've already succumbed to the annual crush washer thread.

C'mon folks. It's going to be a long winter.

Lets save some material for January and February...

Thank gawd we still have oil viscosity, windscreen polish and tires. :rolleyes:

Maybe Mythbusters will come up with some new fodder...

 
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I use "hi-temp" cardboard and it works just fine. :glare:

I'd also go so far as to say, it won't leak even without a washer.

As El T says..

If you have a Dealer change your oil, take a look underneath sometime. You may not have a washer at all. :unsure:

 
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