Like the title says is GL 5 the replacement for GL 4. I went the autoparts store and all the have is GL 5. I asked them about GL 4 telling them I need it for the transmission. They told me GL 4 is no longer made the GL 5 is the replacement for it. So next I called a Mitsu dealer. They told me the same thing. So now I am like WTF. I searched all the old threads I could find on this topic and it seems most people say never put GL 5 in the transmission. Does anybody know if what I am being told is true?

 

AFAIK, you want GL4, not GL5. Supposedly the chemicals in GL5 fluid are no good for the brass synchro rings.

 

use gl4 there are some oils like motul 75w-90 which have gl4-gl5 specs you can buy bgII syncroshift !

 

GL4 is definitely still made. Amsoil and Redline (among many others) both have GL4 tranny oil.