When should I change the Trans fluid?

[Heiseroil]

Ok, I have a CTD with the NV5600 manual trans in it. Its got about 45k miles on it, and I have yet to change the fluid in the trans. I will OF COURSE, be putting Amsoil fluid in it, but I don't know WHEN I should do the change. Any suggestions?
BTW, I already run severe gear diff fluid, and engine oil. The plan is to have the t case and trans filled with Amsoil asap.
Scott

[Herb]

Scott I would do it now and get if over with. With the MTF 5w-30 synchromesh you won't have to do it for a very long time. I will be doing my G-56 6-SP in early spring with Amsoil ATF.

SERVICE LIFE
Recommended for 50,000-mile service intervals or longer (up to 150,000 miles) as indicated in the owner’s manual.

Everyone that I have running the MTF & MTG can not believe the difference in the smoother shifting.

[Heiseroil]

Thats what I was thinking Herb... I gotta get another check before I can do it, but I figured it would be a good idea... Guess I ought to drain my oil container eh? :D
Scott