I flushed and refilled with Castrol Import, which specifically lists the Mitsubishi Diamond III as a compatible brand. 20k since and not a single problem. It even cured some small slipping issues that had begun to arise when the tranny was cold. If I could have easily located or afforded the Diamond III fluid, I would have gone that route, but the Castrol has been good to me so far.

-Austin

1988 SWB Montero - 2.6L - 5-speed
Weber Carb
(Coming Soon) Rugged Ridge AVM Hubs