I purchased this car about a year ago and it runs great. My only problem is sometimes it shifts very abrubtly and other times very smoothly. I checked for vacuum leaks, couldn't find any. I know that on these older cars they still use vacuum modulators, but from my past experience, they usually smoke excessively when the modulator goes bad. Could I have a pressure problem. Does anyone know how to adjust these, I can't find a decent repair manual on this car and when I speak to Mercedes Mechanics here in Cincinnati, they don't seem to know anything about the older cars. I did drain off a quart of fluid from the trans and this allows it to shift smoother, but when it's cold, the transmission slips, after a few miles it will start shifting properly. The trans was rebuilt about three years ago. Would appreciate any help.