by Karl von Salzen
All the GL5's you mention are synthetic.
If you go to the
Amsoil gear oil site you will see it says to use GL5 because it
replaces GL2 to GL4, BUT that is ONLY if you use synthetic! READ
down further. READ the section on Application. Here, I will post
it:
"Application AMSOIL 75W-90, 80W-90 AND
85W-140 Gear Lubes exceed the lubrication and performance
requirements for gear boxes where API MT-1, GL-4 or GL-5 lubricants
are specified. AMSOIL Synthetic Gear Lubes provide limited slip
performance. Although generally not necessary, manufacturers'
limited slip additives may be used in conjunction with AMSOIL
Synthetic Gear Lube.
After changing a vehicle's limited slip
lubricant, drive the vehicle in a tight "figure 8" pattern (lock to
lock turns) for a minimum of eight
repetitions.
AMSOIL 80W-90 GL-4 Gear Lube is
recommended for marine outboard and stern drive lower unit gears
and bearings. It is also recommended where the manufacturer
specifies GL-4 performance. AMSOIL 80W-90 GL-4 Gear Lube is not
recommended as a replacement for API GL-5
products."
READ the last paragragh AGAIN. 80W-90 GL4
IS RECOMMENED WHERE the manufacturer SPECIFIES
GL4.
Maybe you think VW never recommended GL4?
Again, LEARN to read. Here is the spec sheet FROM
VW:
http://www.baywindowbus.com/77infocard.jpg
READ the top right corner: Manual
transmission: GL4!!!!
Do NOT confuse [you probably will] the
FINAL DRIVE of the auto trans THAT uses GL5 with the manual
transmission, they are 2 different things.
GL4 is GL4. It NEVER was replaced by GL5
or GL5 with MT1. I still wish I knew where that MT1 mumbo jumbo
came from. RE-READ ALL the links I posted the last time this crap
came up again.
People, manufacturers RECOMMEND
specifications for a reason. Lots of time and research went into
it. Not just because one or two people used something else NOT
recommended and did not have a problem. Just because Porsche says
Swepco is OK in their trans does not mean it is OK in a VW trans.
Two TOTALLY different transmissions, internally.
The manufacturer has to stand behind their
product, not people that can't read and comprehend. Your
choice.....