Type F trans fluid ?
 

In my offshore boat I am running Huber 923 Borg Warner 10-18 transmissions, they demand that you run type F fluid to maintain maximum clutch holding force. I think it is because type F lacks all the friction modifieres to maintain a smoth shift, Soooo, if you have a built transmission would it be better to run Type F if you want a firm shift and and to hold up to more Tq. ?

i just changed mine and did a little research. put dextron w/ bottle of lubeguard. upon search most big name tranny builders recommend it for their trans. make sure u get all old fluid out and dont forget a filter [coffee]

No- you want to run what the manufacturer says to run- type F can create clutch chatter because it doesn't allow the plates to smoothly engage without the friction modifiers. This can be minor or major and can induce shuddering.

The reasearch I did said that dextron plus lubgaurd only brings it up to ATF+2 standards, which is less than the ATF+4, It might take me a bit to find it, though, I drained out the Dextron outta mine and used Valvoline +4,shifted noticeable better. but I'm due for another fluid change so Amsoil ATF it will be.