Transmission Fluid Question (long)

[LDMartin]

From: "Jason Davis" <ahaz@tamu.edu>
Subject: Transmission Fluid Question (long)

> After reading up on se-r.net and the archives, I decided to change my
tranny
> fluid to Redline MT90.  My car has 58,000 miles, and I remember reading
> somewhere that it needed to be changed at 60,000, so two birds...
> Anyways, I went down to the local NAPA store................snip

Jason, in the past week I too clawed back through the archives and many
vendors on this subject as I was also ready to do a change.  The bottom line
is:  Your know it all buddy at the parts store is the idiot.  And if you
don't want to read the rest of my drivel below the "right" answer is MT-90.
My point of view.

Trans fluid has been discussed at length many times on the list.  When I
distill everything down the answer is still Redline due to the straight GL-4
rating.  It has no sulfurous compounds which corrode the yellow metals in
the trans like brass synchros and bushings.  Now trans fluid is a personal
choice to each car nut and everybody has an opinion.  Also, if you are a
hard core recer you may not care about possible corrosion.  You want the
best there is to add reliability.  The reacer's gearbox is likely to get
taken apart before corrosion is a problem.

There are some other things out there that will "work".  NEO, of F1 and CART
fame, still sells a product called MTF (GL-4) but I consider it too light
for our gearboxes.  It was designed for those cars that use motor oil in the
trans.  It's tremendously shear stable though so it might be ok.  Motul has
a product called Gear 300 that some very smart people swear by.  Does it
have sulfur? Yes but the Motul tech rep tells me the oil is so stable that
those compounds won't react in a negative way in a street driven car.  I
have no idea if he's right.  AMSOIL swears their synthetics won't hurt our
trans but it is still GL-5 so who knows.  Save yourself a bunch of head
scratching and get the MT-90 and forget about it.  If the car is only street
driven you can probably forget about it for 100K miles.  Many would disagree
and I understand the reasons why and do not argue with them.  And tell the
guy at the parts store to take a leap.

Larry Martin
'92 Classic