MT-90 is the one according to Daryl at AA Transaxle, and it is what I
have been using for over 100,000 miles now.  MTL it thinner, and best
for transmissions rather than transaxles, which also contain a
differential bathed in the same oil.
--
Stuart MacMillan
Seattle

'84 Vanagon Westfalia
'65 MGB (Driven since 1969)
'74 MGB GT (Restoring)

Assisting on Restoration:
'72 MGB GT (Daughter's)
'64 MGB (Son's)

Parts cars:
'68 & '73 MGB, '67 MGB GT