why do the automatic transmission not shift properly or not shift at all when engine gets hot?
1993 toyota hiace from japan with 2L diesel engine and automatic
transmission. at first when engine is still warming up the automatic
transmission shifts properly. but after an hour or so of continuous driving and
engine gets hot, shifter starts to falter and don't shift properly. and eventually
won't shift anymore.
check your ATF strainer inside of transmission housing. It could be clogged with dirt and grime. one indication of a dirty strainer is if color of atf is dark pink instead of the normal red.