On the left side of the transmission, there's a plug... you insert the end of a 1/2" drive socket or breaker bar into it and unbolt it... that's the fill plug. Fill it with fluid (Eaton recommends 50W synthetic for their transmissions) until it reaches the bottom of the fill plug hole.
10 1/2 for a total fill.
Installation of countershafts
No, 10 speed does not convert over. You would need to get a truck with either a 13 speed, or a 9C transmission (which is convertible).
I've never heard of an Eaton Fuller 12 speed, nor am I able to find any references to one via Google. I've driven Eaton Fuller 8LL, 9 speed, 10 speed, 13 speed, and 18 speed transmissions - could you be thinking of one of these? IIRC, Volvo marketed a proprietary 12 speed transmission, and Meritor offered a 12 speed automatic, but not Eaton Fuller.
The words "Super 10" refer to the Eaton 10 speed heavy duty manual transmission.
Mary Eaton died on 1948-10-10.
Yes, there's a transmission filter.
Frank Eaton was born on 1860-10-26.
Amos Eaton died on 1842-05-10.
Brian Eaton died on 1992-10-17.
You can fill 10.67 (11 rounded up) 6-ounce cups with 64 fluid ounces.
You fill it until it runs out the fill hole on the side of the transmission.