GL4 vs. GL5

George Selby gselby4x4 at
Thu Dec 12 05:24:53 EST 2002

At 09:21 PM 12/11/02, you wrote:
>But otherwise- where can you =
>get non-synth GL4?? I used to use Castrol in my departed 5kt, but I can't l=
>ocate the stuff anywhere....

The short answer:  NAPA, 11.88 a gallon.

The manual tranny in my Nissan 300ZX all of a sudden wouldn't shift into
second gear about a month ago.  I put some combo GL4/GL5 oil in it the last
time I changed the fluid.  So I changed it again, in hope it would do some
good, this time I used Valvoline Synthetic GL4/GL5 oil.  About 300 miles
later, it would randomly not go into  1/2 or 3/4 (always both gears at the
same time.)  So I figured it was time for a new tranny, and I found a good
used one from a Turbo 300ZX (sightly stronger Borg-Warner T-5 instead of a
in-house Nissan tranny, further I figure the T-5 will be easier to get
parts for in the future, and the ratios are better: 1,2 and 3 are lower and
the overdrive is deeper.)  I got the tranny installed, and was just getting
ready to put in some Mobil 1 GL-5, when this thread popped up.  One other
note, there were large metal chunks coming out when I changed the oil this
past month, and when I pulled the speedo drive (needed to swap this to the
new tranny) there were bronze shavings stuck all over the speedo drive housing.

The old Nissan unit called for GL-4, while the new (to me) T-5 calls for
either GL-4 or Dextron (and it specifically says NOT Dextron II or III,
which pretty much blows the using ATF as a lube out, as I didn't find
Dextron I anywhere.  So I went everywhere (Advance Auto and AutoZone and
Walmart) and everyone had either GL-5 or GL4/GL5.  Finally I went to the
NAPA, and they have all sorts, straight GL-1, straight GL-3, straight GL-4,
straight GL-5 (all in non-synthetic,) mixed GL3/4/5, GL 4/5 and synthetic
GL5 and GL4/GL5.

The rear end calls for GL-5 (my big tip off the they really don't want GL-5
in the tranny, since they call for it in the rear end, they know it exists,
unlike say SF motor oil, which didn't exist when my Nissan was made,) so I
used the Mobil in the diff.

So hopefully the Audi list has saved my Nissan tranny.

George Selby
83 Audi Coupe GT
86 Nissan 300ZX
gselby4x4 at

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