it might be because of my motor mounts that are shot, but every time my car shifts, more so in lower gears, its a hard jerk. like i brace myself for the shift every time.

98 camry le 4 cyl auto

it has a different used jdm tranny

 

If you know you have bad motor mounts, start by replacing them. You can get a pretty rough feel in the car from bad mounts. I'd be inclined to guess that there may be an actual problem though. Automatic transmissions have accumulators. Accumulators do exactly what they sound like they should do, they accumulate fluid during a shift to cushion the shift. If an accumulator spring broke or if one of the pistons in the accumulator is seized up, that could be causing the problem. I don't know on Toyota's if the accumulators are servicable in the vehicle.