I have a bike that requires Gl-4 rated gear lube. That's hard stuff to find reasonably priced, as I only need less then half a qt. I have read that a gl-5 rated oil may harm any brass or copper in the gear box. But I see some brands offer an oil that carries a gl-4/gl-5 rating. How can that be if a gl-5 may corrode internal parts? I'm really not sure if the gear box I'm dealing with has any copper or brass in it, but I like to stick to factory recommendations rather then ruin something because gl-5 is on every street corner. Can someone explain this to me? Thanks.,,
Gl-4 rated gear oil.
- Thread starter BigCahuna
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THE ACTIVE EXTREME PRESSURE ADDITIVES BOND TO THE SURFACE OF THE YELLOW METALS. WHEN HEAT AND PRESSURE INSIDE THE GEARBOX CAUSE THE EP ADDITIVES TO SHEAR OFF OF THE METALS' SURFACES, THE COMPOUNDS TAKE A FINE LAYER OF METAL WITH THEM.
GL-5'S HAVE HIGHER LEVELS OF THESE COMPOUNDS THAN GL-4'S. MANY GL-5'S HAVE INHIBITORS IN THEM TO LESSEN THEIR IMPACT ON YELLOW METALS. SOME ARE SAFE IN GL-4 APPLICATIONS. YOU WOULD HAVE TO DO YOUR HOMEWORK.
OTHERWISE, MANY OEMS USE 75W85 GL-4 FOR THEIR MANUAL TRANSMISSIONS, HONDA, NISSAN, HYUNDAI, ETC.
GL-5'S HAVE HIGHER LEVELS OF THESE COMPOUNDS THAN GL-4'S. MANY GL-5'S HAVE INHIBITORS IN THEM TO LESSEN THEIR IMPACT ON YELLOW METALS. SOME ARE SAFE IN GL-4 APPLICATIONS. YOU WOULD HAVE TO DO YOUR HOMEWORK.
OTHERWISE, MANY OEMS USE 75W85 GL-4 FOR THEIR MANUAL TRANSMISSIONS, HONDA, NISSAN, HYUNDAI, ETC.
AHHHHHHHHHHHHHHHH!
Anyways, getting back on topic...
There are fluids with dual-ratings you can safely use. I ran Motul Gear 300, a 75w90 GL-4 & GL-5 fluid in my manual trans without any issues.
There are fluids with dual-ratings you can safely use. I ran Motul Gear 300, a 75w90 GL-4 & GL-5 fluid in my manual trans without any issues.
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Grab a quart of Amsoil MTG.
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