The problem with most gear is that they will corrode the brass (synchros,
bushes etc) in the box. The problem with engine oils are that they don't
the ideal properties for lubricating gears (performance under high
and shear). Those properties are usually achieved by sulphur based additives
(these cause the problem) but could also be provided by molybdenum or zinc
Oils designed especially for manual transmissions (e.g. redline, amsoil and
others) are the ideal oils for spridget boxes.
If you really want to use engine oil, then a molybdenum-based additive is a
It adds the stability under high load without effecting the abilities of the
perform their job.
From: Foxy Dave <firstname.lastname@example.org>
To: email@example.com <firstname.lastname@example.org>
Cc: David Ramsey <email@example.com>; firstname.lastname@example.org
Date: Thursday, March 19, 1998 7:12 AM
Subject: Re: trans drain plug tool
>If this is true ...
>> I replaced the gearbox oil with synthetic 75w-90. Very nice change!
>> Thanks for the suggestion, whoever it was that mentioned it. Smoother
>> shifting and quieter when hot. One of the nicest easy (other than
>> getting that damn fill plug started back on it's threads) changes I've
>> made for driveability.
>why do the books say to use 20/50w motor oil in the trans ?
>I'm tempted to change over 'cause it seems to make good sense to give the
>gears a heavier oil ..... doesn't it ?
>Does anyone have a good argument to the contrary ?
>Nice tool invention Crash !
>Please put me on the waiting list for purchase ;-)
>At 10:49 AM 3/18/98 -0800, David Ramsey wrote:
>> I have invented a high tech tool that aids in the removal and replacement
>of the tranmision fill plug.
>>> I replaced the gearbox oil with synthetic 75w-90. Very nice change!
>>> Thanks for the suggestion, whoever it was that mentioned it. Smoother
>>> shifting and quieter when hot. One of the nicest easy (other than
>>> getting that damn fill plug started back on it's threads) changes I've
>>> made for driveability.
>> I will be selling these "Pat Pend" tools for the low cost of 29.95 +
>shipping, as soon as the tooling is done. This special tool consists of a
>2" piece of high tech 5\8" rubber hose "heater or garden". All you need to
>to do is loosen the drain plug with socket wrench and place the special
>tool on the plug and remove by hand, to replace the drain plug you just
>place the special tool "Pat Pend" and drain plug on the transmision and
>hand tighten, remove the tool and snug-up the plug with the socket wrench.
>> At this time I have several hundred of these tools in stock (the end of
>my 5/8" sears garden hose got run over by my bug-i). However shipping will
>be delayed about 6 months, because I am waiting for the paper "Made in
>England" stickers to arrive from England.