[T.O.98]

exactly how much oil do i need for my 98 4.6, also what tranny fluid do i need, as i understand the manual tranny calls for auto tranny fluid? is royal purple synchromax what i need (if i go royal purple) and how much of that do i need. my car never came with a owners manual!!!

thanks

[BlueStreak03]

Your crankcase should hold 5-6 quarts when changing the filter also. I'm not sure what lube you need in that transmission. I want to say the RP Synchromax will work, but I'm not sure what weight you want to use. I know NAPA has a pretty extensive database holding this type of information, try giving them a call.

[GTStang31]

Go to www.mustangtuning.com they carry the royal purple line and have the best deal I could find price wise. They also sell Royal Purple ATF fluid.

[engineer76]

I say, don't gamble with fluids containing lots of friction modifiers. Especially not for a tranny.

Stick with what your manual says. Most likely it says Mercon ATF.

Don't put in Mercon V, it has a higher ammount of friction modifier and might cause gear clash/grinding.
The syncros don't bite into the cones anymore.

[GTStang31]

If you look at the mechanic manuals it says full synthetic mercon III/decron fluids are suitable. So full synthetic ATF fluids are good to use.