Honda Car Forum

On Sat, 15 Nov 2008 05:19:49 -0700, Elle wrote:

> "jim beam" <spamvortex@bad.example.net> wrote Elle wrote
>>> Both those bolts use crush washers. These washers will lose their
>>> springiness, requiring excessive torque for a good seal until the
>>> threads strip.
>>>
>>> Yada yada I am sure you know this.
>>
>> yes, they're crush washers, but no, they're not springy, they're
>> plastic
>> [in the materials deformation sense, not polymers sense]. their
>> plasticity is so that they fill the small intersticies in the material
>> surface on both the transmission and plug side, and thus seal.
>
> They may very well be more plastic (and so possessing a greater tendency
> towards permanent deformation)

it's not just a tendency, plastic deformation is the primary function in
order to seal effectively.


> as opposed to springy, but something
> springy would also fill interstices.

not so. with hard materials [springs], you'd have to deform the material
around the washer in order to seal, not have the washer deform to fit its
surroundings. one method has a long term future, the other, not.


> Bottom line is that seals (gaskets,
> washers, etc.) of all kinds are often re-used, and with no subsequent
> leaks, despite being not as effective. The operator is taking a risk.

to a limited extent, sure. but unlike a typical shop situation where the
vehicle operator never sees [not cares] about what's under the hood, much
less whether a drain plug gasket is leaking, i inspect. if it's leaking,
it'll get replaced. if it's not, it won't. that actually has less risk
that using a new washer and not inspecting!

again though, i reemphasize, the big temptation with seal washer re-use is
to over-tighten. that's a HUGE no-no.

"jim beam" <spamvortex@bad.example.net> wrote
Elle
>> They may very well be more plastic (and so possessing a
>> greater tendency
>> towards permanent deformation)
>
> it's not just a tendency, plastic deformation is the
> primary function in
> order to seal effectively.

We disagree. The sealing material to use (springy or not
blah blah) depends on the application.

On Sat, 15 Nov 2008 06:57:54 -0700, Elle wrote:

> "jim beam" <spamvortex@bad.example.net> wrote Elle
>>> They may very well be more plastic (and so possessing a greater
>>> tendency
>>> towards permanent deformation)
>>
>> it's not just a tendency, plastic deformation is the primary function
>> in
>> order to seal effectively.
>
> We disagree. The sealing material to use (springy or not blah blah)
> depends on the application.

with respect elle, copper or aluminum crush washers are not springy.
their sole purpose is to deform [and thus conform] to surface anomalies
and so, create a seal. hard materials simply don't do that - which is why
they're not used!

"Elle" <honda.lioness@gmail.com> wrote in news:VZyTk.461$qh4.383
@newsfe04.iad:

>
> "Tegger" <invalid@invalid.inv> wrote
>> But what about the fill plug washer?
>
> Part no. 94109-20000 (20 mm) for my 91 Civic.
>
>


Well, I just called my parts guy and gave him those two numbers
(94109-20000 and 94109-14000). He immediately recognized both numbers and
knew they were for the oil pan and transmission. He even has them in stock.

Apparently several models use those parts, not just the Civic and Integra.

I do remember now that getting a /drain/ bolt washer was never a problem,
just the one for the /fill/ bolt.

It's been at least ten years since I last asked him for the fill bolt
washer, and he no longer remembers our previous difficulty in finding it.

I'm going to pick up a few of each next time I'm down there.

Thanks for your help.

--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"jim beam" <spamvortex@bad.example.net> wrote
Elle
>> We disagree. The sealing material to use (springy or not
>> blah blah)
>> depends on the application.
>
> with respect elle, copper or aluminum crush washers are
> not springy.

I think we are talking past each other. I am saying that,
generally speaking, some sealing materials are in fact
rubber or similar and so are springy. Other sealing
materials work by plastic deformation. Which is used
depends.

On Sat, 15 Nov 2008 07:13:31 -0700, Elle wrote:

> "jim beam" <spamvortex@bad.example.net> wrote Elle
>>> We disagree. The sealing material to use (springy or not blah blah)
>>> depends on the application.
>>
>> with respect elle, copper or aluminum crush washers are not springy.
>
> I think we are talking past each other. I am saying that, generally
> speaking, some sealing materials are in fact rubber or similar and so
> are springy. Other sealing materials work by plastic deformation. Which
> is used depends.

it's hard to reliably use just a rubber seal under a screw because it's
difficult to torque sufficiently to reliably retain the screw. [ever had
to re-torque a leaky oil pan? usually, /all/ the screws are loose.]

additionally, for drain plugs, as the shear of twisting commences as the
two sealing surfaces contact, it can tear. thus polymers are used for
gaskets, and copper or aluminum alloys are used drain plugs.

jim beam <spamvortex@bad.example.net> wrote in
news:rsSdnWh6d6qBRoPUnZ2dnUVZ_qadnZ2d@speakeasy.ne t:

> On Sat, 15 Nov 2008 07:13:31 -0700, Elle wrote:
>
>> "jim beam" <spamvortex@bad.example.net> wrote Elle
>>>> We disagree. The sealing material to use (springy or not blah blah)
>>>> depends on the application.
>>>
>>> with respect elle, copper or aluminum crush washers are not springy.
>>
>> I think we are talking past each other. I am saying that, generally
>> speaking, some sealing materials are in fact rubber or similar and so
>> are springy. Other sealing materials work by plastic deformation.
>> Which is used depends.
>
> it's hard to reliably use just a rubber seal under a screw because
> it's difficult to torque sufficiently to reliably retain the screw.
> [ever had to re-torque a leaky oil pan? usually, /all/ the screws are
> loose.]
>
> additionally, for drain plugs, as the shear of twisting commences as
> the two sealing surfaces contact, it can tear. thus polymers are used
> for gaskets, and copper or aluminum alloys are used drain plugs.
>



Toyota's OEM gasket for oil pan drain plugs is non-metallic. It's some sort
of hard black fibrous material. Works quite well.


--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

On Sat, 15 Nov 2008 15:26:37 +0000, Tegger wrote:

> jim beam <spamvortex@bad.example.net> wrote in
> news:rsSdnWh6d6qBRoPUnZ2dnUVZ_qadnZ2d@speakeasy.ne t:
>
>> On Sat, 15 Nov 2008 07:13:31 -0700, Elle wrote:
>>
>>> "jim beam" <spamvortex@bad.example.net> wrote Elle
>>>>> We disagree. The sealing material to use (springy or not blah blah)
>>>>> depends on the application.
>>>>
>>>> with respect elle, copper or aluminum crush washers are not springy.
>>>
>>> I think we are talking past each other. I am saying that, generally
>>> speaking, some sealing materials are in fact rubber or similar and so
>>> are springy. Other sealing materials work by plastic deformation.
>>> Which is used depends.
>>
>> it's hard to reliably use just a rubber seal under a screw because it's
>> difficult to torque sufficiently to reliably retain the screw. [ever
>> had to re-torque a leaky oil pan? usually, /all/ the screws are
>> loose.]
>>
>> additionally, for drain plugs, as the shear of twisting commences as
>> the two sealing surfaces contact, it can tear. thus polymers are used
>> for gaskets, and copper or aluminum alloys are used drain plugs.
>>
>>
>
>
> Toyota's OEM gasket for oil pan drain plugs is non-metallic. It's some
> sort of hard black fibrous material. Works quite well.

it uses the fiber reinforcing to address tearing. and being polymeric, it
can't take the same thermal load - academic here though.

jim beam <spamvortex@bad.example.net> wrote in
newsaadnXvYnvgpcIPUnZ2dnUVZ_uqdnZ2d@speakeasy.ne t:

> On Sat, 15 Nov 2008 15:26:37 +0000, Tegger wrote:
>

>>
>> Toyota's OEM gasket for oil pan drain plugs is non-metallic. It's
>> some sort of hard black fibrous material. Works quite well.
>
> it uses the fiber reinforcing to address tearing. and being
> polymeric, it can't take the same thermal load - academic here though.
>


What does thermal load matter? The gasket works just fine sealing against
hot oil in spite of being non-metallic, which was my only point.

A gasket for a fastener does not have to be metallic to be effective and
allow specified torque.


--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"jim beam" <spamvortex@bad.example.net> wrote
> it's hard to reliably use just a rubber seal under a screw
> because it's
> difficult to torque sufficiently to reliably retain the
> screw.

I am talking about seals in general--oil pan gaskets,
o-rings, washers, etc.