Mikael
Are you sure that the filter you changed was for the trans, Most automatic of that vintage have the filter in the pan attached to the underside of the Trans, It sounds like your filter is plugged, I would drop the pan and look at this, also there is ussally a rubber grommet on the filter to the spiggot it attach's to to seal the top side so the tranny pump is able to pull threw the filter off the bottom of the pan, its really a good idea non the less to clean it out.
good luck, Mark
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