Date:         Wed, 3 Apr 1996 18:47:22 -0500 
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         vwbus@TCPBBS.COM
Subject:      Re: '88 Power Steering - ATF Dexron ??

DH>
DH>>I do remember gear oil smelling of sulfur. But I'm still confused. If the 
DH>>"GL" classification of 6 is better than 5 which is better than 4, where 
DH>>does a GL-4 synthetic (ie Redline's MTL GL-4) fit in?
DH>>
DH>>
NO, NO, NO, NO.

IT DOES NOT WORK THIS WAY!!!

The GL rating is a rating describing the wear additive formulation
(hence
some smelling of sulphur, some not).  GL4 is the ONLY correct
formulation
for a VW box of any type.  I swear on my not yet dead mother's grave if
you put something other than a GL4, even a GL4, GL5, GL6 rater in a new
VW box and a problem does develop under warranty and they find out you
will be up the proverbial crick.  There is a lengthy FAQ about this
whole
thing on the FWD VW FAQ server who's address I forget (it is on the
standard
MIT FAQ archive as well).  I'm going to print out MIL-L-2105 and the API
standard tomorrow and I'll summarize for the list.  In MIL specs the
type
simply refers to a different and perhaps totaly incompatible formulation
often arbitrarily assigned, there is NO GL6, better than GL5, better
than GL4
sequencing instead one is for say clutch type limited slips, one has
sulphur-
phosper additive (GL4 OURS) etc.  Now Redline and others will claim
now-adays
that the new synthetics are so stable that they will not hurt any box,
still
they make GL4 ONLY oils specifically for VW's the MTL and MT90 and VW
will VOID warranty if they figure out you used something else, there
was much
discussion about this on the early days of the Corrado list as early
G60's have
tendancies to eat 2nd gear synchro hubs.  It is the metalurgy of the VW
box
particularly the synchros that requires a GL4 oil.  Your ultimate safe
bet is VW
synthetic factory fill at $30+/qt from your local dealer but Redline
stuff is race
proven as well.

BTW, must correct an earlier statement, MTL is actually thinner than
MT90, some
racers use it in FWD boxes for quicker shifting, less drag, however the
above
mentioned FAQ has a number of claims pro and con, some say it killed
their
tranny, take your chances, MT90 is right for FWD, MTL for Vans

John
vwbus@tcpbbs.com