Hard Shift When AC ON

[ks2004]

Hi Yall,

The car in question is a 1993 190E 2.3 Automatic with 130,000 miles. The tranny usually shifts fine, but with the A/C turned On, it shifts alot harder. It feels like when there's a large load on the engine, the tranny will shift harder. I've visually checked the vacuum rubbers that I can find, and replaced quite a few of them. After replacing the rubbers, the tranny shifts alot smoother, but still not totally smooth when the AC is ON. I've also adjusted the vacuum modulator. I'm just wondering if the big different in shift firmness is normal. Or it is a symptom of some other problem?