s2000maniac

My s2k had a aftermarket driver side axle and it used to shake around 75mph. So i decided to swap in an oem axle and also swapped the bucket. I only swapped the driver axle bucket coz I had a spare passenger side axle. Installation went smoothly and I took it for a drive and I kinda noticed while making a sharp right turn, if I pressed the gas a lil harder it felt like the left rear side was losing traction. It didn't do that before and the whole drive train feels "tight", before it had a lil bit of slack. If I'm driving normally at any speed and when I take my foot off the gas and quickly tap the gas pedal, the whole car lurches forward with sort of like a kick. It didnt seem to that before. I also noticed that the aftermarket axle had a lil play while the oem axle didnt. I dont know if this normal or not. I cant really compare since I never had a oem axle on the car before. The shaking seems to be gone and the car feels kinda smoother than before.
I was thiking what if one of those axle bearings didnt set in properly or its miss-aligned and causing these issues?