20-25 Years with proper maint.
Eaton Fuller recommends 50W synthetic. Not sure about other transmission manufacturers.
On all Eaton-Fuller transmissions, the fill plug is on the left side of the transmission. You insert the drive end of a 1/2" socket into it, and turn it counterclockwise to unthread it. That's where the transmission oil goes. Eaton-Fuller recommends you use either 50W synthetic, or 80W if you're going with mineral oil.
Fuller Transmission shift diagrams.There are several places on or offline where you can obtain and Eaton fuller 15 speed gear shifting diagram. It depends what method you prefer. such as from your Truck dealer or a Truck Transmission Re-builder or someone who offers fuller transmission parts and service. For more information of sources online, see the Related Links section further down this page.
Either a proprietary Mack 18 speed or an Eaton-Fuller 18 speed. Various models of the Eaton-Fuller were available, from 1600 torque to 2100 torque.
Keep rpm between 1400 to 1600
Overdrive. The "O" in "RTLO" indicates that, and the transmission in question has a final drive ratio of .73.
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.
It's known as a "Super 10"
If it's an Eaton Fuller, 50W synthetic or 80W mineral.
A eaton fuller 18 speed roadranger gearbox is used
It's the same as the shift pattern for the Eaton Fuller nine speed transmissions, albeit with additional gears on the low side. For the sake of not wanting to type out a long winded explanation, there is a related link posted - 'Eaton Fuller 18 speed shifting diagram'. Click on that link to see a visual representation of the shift pattern.
Eaton-Fuller recommends either 50W synthetic or 80 weight mineral oil.