Can't wait for some responses on that one.
To all the other PEs out there, I welcome any informed rebuttal.
I don't want to waste my time generating a response so I'll let the good folks at AMSOIL list the perils of using ATF in a wet clutch motorcycle transmission:
"Viscosity is the most important characteristic of a lubricant. Motorcycle gears create a shearing effect that causes permanent oil viscosity loss. This thinning effect reduces the oil's ability to prevent metal-to-metal contact and wear. The stability and natural operating temperature ranges of the premium synthetic base stocks used to formulate AMSOIL Synthetic Motorcycle Oils eliminate shear and reduce wear. AMSOIL Synthetic Motorcycle Oils exhibit absolute shear stability as measured by the Kurt Orbon shear stability test."
AMSOIL Synthetic Universal Automatic Transmission Fluid (ATF) Kinematic Viscosity @ 40°C, cSt (ASTM D-445) 32.4
AMSOIL SAE 10W-40 Synthetic Motorcycle Oil (MCF) Kinematic Viscosity @ 40°C, cSt (ASTM D-445) 93.36.
High Shear Viscosity @ 150°C , 1.0 x 106 s-1 (ASTM D 4683), cP 4.52 (Kurt Orbon test)
I direct your attention to the 93.36 rating of the made for motorcycles MCF along with the respectable shear rating of 4.52 vs the 32.4 viscosity rating and no shear rating for the ATF.
In addition to the above good news about ATF, over the years, new and improved ATFs have been developed to meet the changing demands of newer ATs. For instance, type f and the newer type fa has more friction modifiers for Ford transmissions. Dexron was actually developed for a softer shift feel. The newer versions dexron III, merconV, Toyota type4, etc., were all developed for specific problems that arose from newer model transmissions (torque converter shudder,slow flow rate thru valve-body&solenoid packs,etc..). So, in a nutshell, you don't know what you are getting since nobody has ever conducted any performance or compatibility test on ATF in motorcycle transmissions.
At the risk of repeating myself, ATF is designed only to satisfy the performance designs/goals of a automatic automotive transmission, not the demands of a motorcycle gearbox.
One last "jewel" I'll leave you with. Some ATFs will swell/soften rubber components and others will shrink/harden them - watch out for those seals!
dogger