We have a 87' 420SEL and the auto transmission has started to shift very rough when shifting from 1st to second and less rough shifting from 2nd to 3rd. It feels the way a manual transmission feels if you "drop" the clutch. The rough shifting is more pronounced when you accelerate slow and not as bad when you give it a little gas. The filter and fluid were changed about 25 k ago. Fluid level is fine, driveshaft, u joints, and rear end are fine. What could be the problem here? Is it a repair, and adjustment, or do I need a new tranny? If I need a new tranny would I be ok to get a rebuilt? And what are the potential costs of all this?
Thanks in advance for any help.