so even the westerbeke dealer here said that the dextron 3 and 4 oils should work fine as they are formulated to work in place of the type F, even though the manual calls for type F oil WITHOUT additives.
Now, after some time using the dextron III oil in the paragon transmission, it was still over heating at higher speeds. it runs cool as long as I dont crack the throttle too far open, but with too much power on, it will get hot enough to boil the oil out the vent.
this is not acceptable to me....
so i dug deeper into the design of the sintered bronze wet clutch discs that paragon used in these gearboxes and found what the causes of over heating are with them. the wrong oil is the leading cause.
more searching and I found that the recomended type F and also the type G transmission fluids are the only transmission fluids that do NOT have friction modifiers in them.... it spicifically specifies that they CANNOT have friction modifiers in them to get the type F or G rating.
dex III does have modifiers and other additives in it....
friction modifiers are what help the discs slip smoothly into and out of engagement. without the modifier additives, the discs hold their grip on the separator plates much better as more power is applied.
the paragon reversing gear box (transmission) that westerbeke put behind many of their engines are NOT supposed to have friction modifiers in them. they want the the discs to lock up solid without slippage when the lever is engaged... the friction modifier can allow the clutch discs to slip under full load with the larger Hp engines, causing excessive heat.....
so I searched for and found a type F oil.
I changed out the dex III with the type F oil and ran it for a few minutes at high power while tied to the dock, then changed out the oil again to flush all the dex out of it... then refilled it with type F oil and ran it again for 30 minutes at nearly full power while monitoring it.
the over heat problem is gone..... and im happy
