Hey guys, going to change my trans fluid and filter soon in my terex, has the two speed allison in it. The tranny calls for c-2 fluid which the local napa store says crosses to a valvoline fluid called unitrac hydraulic fluid. On the bucket i bought it says c-4 allison approved. Do you think that c-4 is ok in a c-2 tranny? i was thinking they may have superceded the c-2 with c-4 but i want to check with you guys to see what you think. Thanks in advance! Brian
C2/3/4 all about the same, but check the oil specs close to make sure. Go on-line to oil manufacturer website and check the product listings, you might check with Allison or Terex dealer too. Good Luck!