I don't mean to pick on you but I think people over complicate this stuff. I guarantee that normal operating conditions will not break down a synthetic 20-50 oil in your transmission before the 10k mile service interval. Sure, there's better stuff out there. But for the common garage mechanic, it's really convenient to be able to pour the same fluid in all 3 and call it a day.

 

You nailed it. There's always something better but for the average rider and home garage mechanic, it's nice to be able to use the same fluid in all 3 places.

Not trying to stir the pot but the OP asked if it was possible. Answer is yes, it is possible.

 

You can probably use 3-in-1 oil in the primary but it doesn't mean you should. I've done fluid changes in all kinds of bikes and always was instructed to use gearbox oil in the gearbox. Now, this goes back a long way but I still think the basic principle holds.
It can't be that inconvenient to open a bottle of Red Line or something similar and dump that in the gearbox.

 

You can get up in the morning and pour water on your cheerios if you like but I prefer milk.
Gasoline will work to light your charcoal but use lighter fluid. So I guess it's a matter of personal preference and convenience. What movie was that where they used dish soap in the washing machine? Funny stuff.

 

It's not good to run an oil with friction modifiers in your primary's. Hence the reason Mobil 1 makes V-twin 20/50 for bikes and regular Mobil 1 20/50 for other applications.

 

Considering Baker Transmission is in the business of building and repairing transmissions for motorcycles and not in the Oil and gas business - I will personally follow Mark's recommendations - seriously how difficult is it to walk a few short steps to get a different lubricant when your shopping - especially when it will work better - gezzzz but to each their own

 

I use the Mobil 1 in all three with no issues.

 

I know this has been a long on going debate but it's very informative and I'm sure there are others who can use the info... So keep the opinions coming y'all

 

I don't take it as being picked on. You have your opinion and I have mine that's the whole point of this forum. I will continue to use gear oil in my tranny and motor oil in my engine. If I wanted "convenience" I'd take it to the dealer and let their hacks grind away on it. Nothing over complicated about that.

BTW, if you take your argument to it's logical conclusion you would be arguing against the use of synthetics as it's not needed under "normal operating conditions".

 

That was cute and clever, but a little short on the confidence-building technical explanation end.

Do you have a transmission dyno, or something like that which most of the major manufacturers have, and run exhaustive longevity tests on before making a lubricant recommendation?