Hello All,


I just had an independent replace the differential on my 1984 300D. Since driving the car (picked it up Friday) I have noticed a sluggishness which is pronounced in city driving and under hard acceleration. The car also has trouble getting over 80 mph. A "quality" used unit was installed. Upon doing some research I came across there are several models with different ratios for these cars with two being implemented in 1984. My car was manufactured 10/84 thus supposedly using the faster version used in 1985. Does this sound correct? I am not well versed in the drivetrain area of the W123. The repair is unacceptable and will have to be followed up. Is there another part that might need adjusting or does this sound like an incorrect or bad differential? No fuel economy problems or rough power delivery. Just slow. All maintenance is up to date. Was superb before except for a whine.