
I'm just slightly curious as to why the correct type of ATF is critical for certain transmissions.
For instance, what *actually* happens if you drain (fully as in T.C drained too) and then refill an AL4 completely with something like Dex2 or 3 ?
Does it function normally for a while or are jumpy changes noticed straight away due to the differing pressures being applied by fluid pressure to the bands ?
I can't see it having no drive at all though.
I probably should know but I'm struggling to think what is actually different in the special oils. Normal ATF types do provide 'some' lubrication quality so items such as shaft and diff bearings would not suffer I guess. I'd suspect (I've not checked) the major differential components (crown/pinion) in the AL4 are not that far off the ones in the 4HP20 unit (the mechanical predecessor to the AL4) if not the same apart from a ratio change possibly.
Is it its viscosity when hot / cold or its reaction to different materials (brake band material types) or its behaviour under extreme pressure ? (I'm thinking in the torque converter mainly)
Just questions from the highly curious (aka: me) that is all.
