I have a 2001 ford ranger 2.3. 2wd automatic I found a transmission for a 2003 3.0 2wd ranger. I know the bell housing is different . But why can't I change that and it work? Same plugs same part number ect. Any help ?

 

Removable bell housings were lost back in the mid-80's

Ranger A4LD automatic in 1985 and all automatics after that had integrated bell housings

2001 2.3l will also be a Duratec engine not the earlier Lima 2.3l, so you will need to get trans from 2001 or later 2.3l Ranger

2.3l, 3.0l and 4.0l all have different bolt patterns for trans

 

No my 2001 2.3 duratech the bell housing is removable, and the 2003 3.0 is removable

 

OK, bad explanation on my part, the bell housing on the automatics do come off in order to rebuild the transmission.
Bell housing is part of the Front pump(main pump), not just a separate shell piece, like on the old manual transmissions.

I would think that if both were 5R44E then you may be able to have a transmission shop swap them, but it would be almost the same as a rebuild.

Good look here at bell housing use on automatic: