My Case w/ Allison trans calls for C2 trans fluid. Can I use C4 or will this eat my seals?? I'm asking about topping off w/ C4, so there will be a mix in the transmission. Is that a problem??
If its on the allison approved list it will be backwards compatible. Heres a link http://www.allisontransmission.com/service/autoapp/172/index.jsp?