His words are true...but they are dated. For a long time, we all ran gear lube
in
our gearboxes. With the drive to get drag down (increase mileage and power),
thinner lubricants were tried in transmissions. Loe and behold, they tended to
work just fine. Today, you've got manual transmissions running around using
atf.
Even ancient iron is getting converted. My 1951 Ford tractor calls for 80
weight
in the drivetrain by the original owners manual. Yet Ford (ok, NewHolland
actually) went back and reworked the oils, recommending 134F, which is roughly
a 15
weight oil. The reason? It reduces parasitic drag, makes the hydraulics work
better, and does just as good a job at protecting the gear teeth.
The one caviat I'd stick in here has to do with differentials. That action is
far
harder on gear lubes then a mere transmission. Hence the GL-5 specifications,
using EP lubricants. However, even that has been frequently superceded with
motor
oil and even ATF. Just look at the lubricant recommendations for various
Japanese
fwd cars. With the differential in there, they are running 10-30 engine oil,
and
even atf. Wouldn't care to try to go 20 years without ever changing the oil,
like
so many of us actually have in our various differentials. But it does work
fine.
So, personally, I think the Mobil tech was being correct and very cautious in
his
recommendations. Would the oil work? I'm sure it would do just fine in a
transmission. But, if one deviates from the owners manual, one runs a risk.
Really want to drive yourself nuts? Try to find out the proper oil for a
Laycock
overdrive. The automobile manufacturer recommendations run from 90wt gear lube,
through engine oil, and all the way down to ATF. I've never been able to find a
recommendation specifically from Laycock themselves.
If you want to explore synthetics for a transmission or differential, Redline is
probably one of the best places to start. They have many types, with very
specific
optimizations. At the least, it's worth spending some time on their web site
studying their pages.
Mike & Kerry Gigante wrote:
> Remembering that I am struggling to recall exactly what he said.
>
> Having said that, I understood that conventional oils had more
> suitable mechanical properties for gearboxes. We really should
> try and find a source at Mobil though - I don't want to be the
> source for a new urban legend!
>
> Mike
>
> ----- Original Message -----
> From: <Daniel1312@aol.com>
> To: <mikeg@vicnet.net.au>
> Cc: <spridgets@autox.team.net>
> Sent: Tuesday, February 13, 2001 5:22 AM
> Subject: Re: Tranny oil
>
> > Did the Mobil tech expert mean that Mobil 1 was not suitable for use as a
> > gear oil or did he meant that it was not as good as Castrol GTX 20/50, or
> > supermarket 20/50 or whatever? Also does it mean that Mobil 1 is no good
>for
> > gearbox in sump engines like the Mini?
> >
> > Mobil do a synthetic gear oil.
> >
> > Daniel1312
> >
> > In a message dated 11/02/01 23:24:21 Pacific Standard Time,
> > mikeg@vicnet.net.au writes:
> >
> > << I vaguely recall a comment from a Mobil tech expert that Mobil 1 wasn't
> > suitable
> > for
> > gearbox use because its shear properties were inadequate for the
> > application. >>
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