98 windstar

98 Windstar has had a slight clunk when shifting from first to second for the last 20k miles. Today at 108k miles the clunk became a major slamming clunk when shifting into second. The check engine light came on a few minutes later. Coincidence? Transmission fluid level is OK and appears clear. Trans fluid flush was at 75K miles. Even at the most gentle acceleration, the problem is extreme. Any suggestions.

Is the clunk accompanied/caused by a harsh tranny shift? Letting it go for 20K cant be a good thing :uhoh: . Could be a bad CV joint, motor mount, or maybe a bad speed sensor causing harsh shifts.
G/luck
Joel