Transmision Fluid?

[Jeff August]

Can someone please tell me the type of trans. fluid the allison uses,
the manual I have only says the amount it holds,it leaks a small amount
out the copper tube that comes out the tranny where it tapers down to
the drive shaft when its driven(overflow?), level seams fine but if I
add some I would like to add the rite kind.
Thankyou Very Much!
Jeff and Michelle August
1980FC35RB(with a 89 motor)
Plymouth Wi