Re: [OMC-Boats] OMC Type C lab testing

If the OMC engineers specified a gear lube, it was for good reason and I
wouldn't substitute an ATF. ATF and gear lube are dramatically different
animals. From a gear perspective, you can only use ATF with helical, bevel,
and spiral bevel gears. Hypoids need gear lube to address the sliding
motion of the gear teeth induced by the offset. (For those not familiar
with the terms, a spiral bevel is a hypoid with no offset -- the pinion
centerline intersects the ring gear centerline. Of course a spiral bevel is
also a bevel gear with curved instead of straight gear teeth.) On the flip
side, you wouldn't want to use a gear lube in a hydraulic application
because the pumping losses would be tremendous at colder temperatures. The
only time I've substituted ATF for a gear lube was on a transfer case where
I knew the gear lube was used solely to have a common lube between the axles
and t-case for service simplicity. Otherwise the two are not
interchangeable, generally speaking. Again, from a gear perspective, ATF
will have a much thinner oil film which means you will spend more time in
the "boundary" or "mixed regime" regions instead of the hydrodynamic
region....which translated means gears will wear faster. Modern
transmissions are loaded with electronics/wires (as are many transfer cases
and axles) which means the lubes must be obviously compatible. With a
little online effort you can look up the certification (i.e. certified to
SAE or ASTM standard....) on the lube at your local store and see if it
meets your needs.

----- Original Message -----
From: "Lee Shuster" <lks@...>
To: "Evinrude & Johnson Boats of the 1960's and 70's"
<omc-boats@...>
Sent: Sunday, August 30, 2009 6:42 PM
Subject: Re: [OMC-Boats] OMC Type C lab testing

> I'll let you do the math. OMC built electric-shift stern drives from 1962
> to 1977.
>
> Yours is most likely a 1964 - 1970. I would call tha ant "older," OMC
> sterndrive in relative terms, for what that's worth?
>
> I'm not that familar with the properties of Dextron II or III having
> never owned a GM product that uses it in an automatic transmission.
> I've never seen a cross-reference to Dextron as a recommended OMC Type C
> subsitute. But who knows? Maybe it has similar properties?
>
> It's easy to use google to look up the properties of GM's Dextron II or
> III :
> http://www.realhamradio.com/Pennzoil%20ATF%20MSDS.pdf
>
> It does have a high dialetric property (35 kV), but I can't vouch for the
> other parameters compared to the specs for "real" Type C or "Premium"
> Blend.
>
> If you wanna try and use it fine by me. If I was in your shoes, I'd
> drain it ASAP and put the right stuff in there, regardless of cost.
>
> Congrats! You've stumbled onto an interesting point, and again this is
> NOT a dumb question.
>
> Lee
>
>
>
>
>
> On Aug 30, 2009, at 4:19 PM, Justin DeSantis wrote:
>
>> I always heard that the dielectric properties are what makes type C
>> different. But I'll tell you where my concern came from. Today being
>> Sunday, I couldn't go to the boat shop to get OMC Type C gear lube. I
>> had 3 tubes of Sierra brand type C, which I was comfortable with. But
>> the local hardware store had tubes of marine gear lube that was marked
>> suitable for Type C applications. I was shocked they had it, so I
>> grabbed a couple tubes, just in case. It was cheap too. I think it was
>> Citgo branded. Anyhow, while it says type C on the front, on the back,
>> in smaller print it said something to the effect of "Not suitable for
>> use in some older electric shift outdrives that require Dextron II or
>> Dextron III fluid." So that gave me reason to pause. Why would it be
>> Type C yet not be suitable for some electric shift models? Anyhow,
>> that was the reason I asked.
>>
>>
>>
>> On Sun, Aug 30, 2009 at 5:04 PM, Lee Shuster<lks@...> wrote:
>>>
>>> One other note I forgot to mention.
>>>
>>> My Dad, who introduced me to boating holds a Chem Eng degree for Ohio
>>> State.
>>> He worked his entire career for Ashland Oil, the parent company of
>>> Valvoline.
>>>
>>> Back in the sixties, we owned an electric-shift J/E V4. My Dad was also
>>> curious about the "mysterious" OMC Type C lubrication requirement and
>>> had a
>>> sample tested by the Valvoline engineering labs.
>>>
>>> They reported back (and I don't have their response) that their testing
>>> revealed some amazing qualities:
>>>
>>> What I remember in their report was:
>>>
>>> 1) very high diaelectric (non-conductive) properties (that makes sense)
>>> and
>>> 2) excellent anti-corrosive properties.
>>>
>>> I can't recall if they ever "reverse engineered" and offered their own
>>> Type
>>> C product, but they were extremely impressed.
>>>
>>> Just buy the right stuff and be done with it, No biggie.
>>>
>>> Lee
>>>
>>>
>>>
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>>>
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Received on Sunday, 30 August 2009