5 ton t-case air ports

[bigford]

Got a question on the air ports: Which one is for forward and which is reverse? The t-case and drive train are not under a mil truck. Asked for a set of manuals on the cd but they have not arrived yet and I would like to do some testing this weekend.
Thanks in advance.

 

[rizzo]

guessed and got it right, but cannot remember which one is which