tranny fluid change

hey guys, this is my first tranny fluid change, what do u guys use fluidwise? and what is the easiest way to drain and dispose of cleanly? thanks for all the help as usual

i hear ur the man, thanks eric

82ski2001 wrote: one more thing, alotta other forums are saying that the older boats used 20w oil. why is that? and it said one place the 20w makes is quieter and smoother. do i need take the lines off to get the old oil out, or will that liitle bit not hurt anything. sorry for all the questions

Listen to Eric, he makes his living fixing these and offers the best advice.

Do you mean dextronIII/Mercron? I know my ford transmission in my truck calls for Mercron ONLY, but it is Dextron III/Mercron. I had the person that rebuilt my trans say any old trans fluid is fine. I change it every year.

Let me know about the Dextron III/Mercron rating.

Thanks Eric. I think I have some in the garage.

Dans, you decide, every trans school i went to, Twin Disc, Funk, Clark that was always one of the top questions....and the answer always was none of these transmissions are designed to use synthetic oil because it robs the co-efficiency of friction which makes the plates break free easier than they do with normal oils
that basically was the only reason, In a transmission you do not have cast iron running against similar metals like piston rings in an engine, there is no real contact of anything inside the trans besides the clutch plates, (ball bearings roll) and in a transmission you are relying on the friction to hold the plates together.
Chances are you probably will never see a problem running the synthectics in these transmissions because of the prop size (small) these transmissions are also used in larger boats spinning twice the prop and these are where the synthetics would probably be noticed.
Is there any advantages to running synthetics in a transmission?? I cant think of one

here is a good way to understand transmissions: if you put your hands together as if you were praying, your left arm is the engine and your right arm is the prop shaft and your hands sandwiched together is the transmission, if you put molasses between your hands and try to spin them you will have a tough time, now if you use hand creme between the two it is easier to spin them free of eachother, this is a good example of using synthetics (hand creme) when building higher horsepower trannys you always take this into account and a couple things you do is: increase hand size (piston) add more hands (cluthes) push hands together harder (more pressure) dont use hand creme (oil)
hopefully this will answer your question and it makes it easier to understand how the trans operates
BTW, your hands sndwiched together is considered the co-efficiency of friction

yeah, i would dilute and then flush with normal Dexron/Mercon and then use it from here on out

no dangers

eric,
I guess i am confused...but what if you have no idea what the PO used before. I am reading that i should just change whatever is in there to DexronIII/Mercon?????