Transmission fluids
Tourer
Joined: Feb 2011
Posts: 479
Likes: 1
From: Oregon
I've used 75-90, 75-140, syn+. It's all the same, noticed no difference. My dealer is close, it's easier to buy 5 qts syn+ and filter and do all 3 holes. 90wt gear is roughly the same viscosity as 50wt motor oil anyway.
Road Master
Joined: Mar 2009
Posts: 962
Likes: 0
From: .....
A gear oil is made for the way the gears mesh in our transmissions. Gear oil has a different additive package that is specific for the application.
I use red line shockproof heavy. I have also used royal purple and it worked just as well as the shockproof does.
Gear oil is far superior to using an engine oil in the tranny.
I noticed on both amsoil and mobil's websites they recommend the v-twin oil in the tranny,so I emailed both to ask why when it's obvious that a gear oil is formulated for just this type of application.
I was informed that both amsoil and mobil recommend what is consistent with the manufacturers(Harley) spec.
So because Harley recommends it so will the oil company,however as a footnote amsoil recommends severe gear.
Basically I was told gear oil is formulated for this type of application but because Harley says use syn 3 the oil companies suggest their equivalent,even though gear oil is superior the oil company will not go over Harleys head and recommend gear oil first,only secondarily if the v-twin stuff is unavailable
Interesting tidbit of info
I use red line shockproof heavy. I have also used royal purple and it worked just as well as the shockproof does.
Gear oil is far superior to using an engine oil in the tranny.
I noticed on both amsoil and mobil's websites they recommend the v-twin oil in the tranny,so I emailed both to ask why when it's obvious that a gear oil is formulated for just this type of application.
I was informed that both amsoil and mobil recommend what is consistent with the manufacturers(Harley) spec.
So because Harley recommends it so will the oil company,however as a footnote amsoil recommends severe gear.
Basically I was told gear oil is formulated for this type of application but because Harley says use syn 3 the oil companies suggest their equivalent,even though gear oil is superior the oil company will not go over Harleys head and recommend gear oil first,only secondarily if the v-twin stuff is unavailable
Interesting tidbit of info
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Road Master
Joined: Mar 2009
Posts: 962
Likes: 0
From: .....
A gear oil is made for the way the gears mesh in our transmissions. Gear oil has a different additive package that is specific for the application.
I use red line shockproof heavy. I have also used royal purple and it worked just as well as the shockproof does.
Gear oil is far superior to using an engine oil in the tranny.
I noticed on both amsoil and mobil's websites they recommend the v-twin oil in the tranny,so I emailed both to ask why when it's obvious that a gear oil is formulated for just this type of application.
I was informed that both amsoil and mobil recommend what is consistent with the manufacturers(Harley) spec.
So because Harley recommends it so will the oil company,however as a footnote amsoil recommends severe gear.
Basically I was told gear oil is formulated for this type of application but because Harley says use syn 3 the oil companies suggest their equivalent,even though gear oil is superior the oil company will not go over Harleys head and recommend gear oil first,only secondarily if the v-twin stuff is unavailable
Interesting tidbit of info
I use red line shockproof heavy. I have also used royal purple and it worked just as well as the shockproof does.
Gear oil is far superior to using an engine oil in the tranny.
I noticed on both amsoil and mobil's websites they recommend the v-twin oil in the tranny,so I emailed both to ask why when it's obvious that a gear oil is formulated for just this type of application.
I was informed that both amsoil and mobil recommend what is consistent with the manufacturers(Harley) spec.
So because Harley recommends it so will the oil company,however as a footnote amsoil recommends severe gear.
Basically I was told gear oil is formulated for this type of application but because Harley says use syn 3 the oil companies suggest their equivalent,even though gear oil is superior the oil company will not go over Harleys head and recommend gear oil first,only secondarily if the v-twin stuff is unavailable
Interesting tidbit of info
