I have a 93 940 wagon, i had to drop the driveshaft to replce the fuel pump in the gas tank, I did not think to mark the position of things when i pulled it apart, but i have my u joints all lined up and on the front half shaft it has a counter wieght ( i guess) also on the rear half shaft it has 2 counter wieghts, one off set from the other, so i aligned the one on the front halfshaft and the one one the rear of the rear halfshaft up, everything was fine, till recently, it seems like the engine is bucking when i brake moderately , i can fell it and see this bucking in the shifter, what should i look at to stop this , i have already checked motor mounts and the tranny bushing, them seem ok, but i can't really find any info on how to check them, also read about run out, on the rotors, i have brand new rotors and pads, the low speed movement is gone, this braking from 40 or so is tearing my car up i am afraid ! sorry for the long letter, anything you can suggest will be appreciated !

Thanks