Date: Fri, 1 Sep 2000 08:57:20 -0500
Reply-To: k1cajun <k1cajun@PIPELINE.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: k1cajun <k1cajun@PIPELINE.COM>
Subject: Re: Finally found some inexpensive GL-4 transmission oil!
Content-Type: text/plain; charset=us-ascii
David Marshall wrote:
>
> ... there is a small privately owned bulk
> oil agent here in town and they had a 25L bucket of GL-5 that was GL-4 and
> GL-3 compatible made by Texico for $32.95 CAD... just passing on the tid
> bit for other people in the need!
>
You might want to read what Pennzoil has on their website
http://www.pennzoil.com under Frequently Asked Questions (question #2).
There seems to be a problem with their HTML code that makes this page
not display properly for me at home and at work. I get a blank screen,
but then I use Netscape's 'View - Page Source' menu to see the HTML code
where you can read this:
===== Beginning of cut & pasted Penzoil text =====
2. What happens if API GL-5 gear oil is used in an API GL-4 gear oil
application?
API GL-4 and API GL-5 products typically use the same extreme pressure
(EP) additive system, with the API GL-5 having about twice the
concentration of a API GL-4. In service, these additives become active
under extreme load and temperature when the protective oil film can be
squeezed away. EP additives work by forming wear-resistant compounds
with the metal of the gear tooth surface. As the gears mesh, these
compounds shield the gear teeth from direct metal-to-metal contact that
would cause wear and damage to the gears. If too little of the active
additive is present, proper protection would be compromised. Too much
of this additive could cause excessive chemical corrosion of the gear
surface. If an API GL-5 gear oil is used in a application where API
GL-4 gear oil is called for, chemical corrosion of "yellow metal"
components may occur, such as bronze synchronizers, brass bushings,
etc. This may lead to shifting difficulties or shortened equipment
life.
===== Ending of cut & pasted Penzoil text =====
So they say that double the additive makes the lube GL-5. But it still
has the required amount that defines lube as GL-4. So it leads to a
definition problem. Is it still GL-4 ? Some manufactures will define
GL-5 as also meeting the specs for GL-4 since the definition apparently
does not say what the upper limit is. But Pennzoil doesn't see it that
way and does not consider GL-5 as being GL-4 at the same time. I've had
discussions with someone at another discussion board who says his
sources, including a chemist, says it's OK to use GL-5 and that it's an
old wives tale that it will hurt your tranny. He admitted that Pennzoil
might be right.
So keep this in mind. It's all up to who do we believe. Some
manufacturers and FLAPS may simply be trying to shave production and
inventory costs by providing only one product. If the damage is done
over the long haul, it's hard to pin anything on them.