Whattup FNG... first post is a tech question, sheeesh..... hit the introductory page so we can get comfy with ya.....
Would a bad water pump seal cause bubbles in trans?
Definately will add water to it and bubbles if it is...... easiest way to check is drain your oil and see if water is in it. Gunna cost what.... about 6 bucks and then you have peace of mind and fresh oil
If the oil is cold then the water will be more seperated and easily detected as long as you don't run the motor and mix it up good and frothy...
when I REV the engine it looks like the trans fluid is boiling when I have oil filler plug off.
Hmmmm, you are really infatuated with this oil situation.... hehehe. This is normal because the clutch basket is about 1 inch below the filler and it is spinning as the motor is running. The clutch basket lubricates itself by being partially submerged in the oil and when it spins it flings the oil like crazy inside.... hence the roiling/boiling/rapid effect of the view through the filler hole....
And the oil looks milky. With to me would indicate water in the oil.
I must assume that you mean through the little looking glass... the level window? probably has a white'ish film on it when its cold still? Depending on temperature, humidity, type of oil and how old it is will effect this situation you are having. Cold temps make more condensation and the air that is trapped inside the crankcase cavity will make a little moisture and wallahhhh.... milky effect. Add cold temps and higher humidty and the scenario gets worse. Now add cold temps, high humidty, and older oil/cheap oil and its gets even worse.
Nowwwww..... add cold temps, high humidity, old oil, and you drooling through the oil filler hole watching the the inner workings of your bike like a beautiful, thunderous, raging river of mechanical bliss..... well, you get the point
BTW, welcome to the club
Sly