When you say de tweaking, are you just loosening and tightening the screws back up and throwing it on the track .....or are you doing that, throw it on a tweak station to get the shocks right, then adjusting ride height, droop and everything from there ?
What you are describing sounds to me like you need to put your car on a tweak station. Mine used to do the same exact thing, i didnt know what it was til someone put it on a tweak station.
Car could be out of balance
Bearing could be bad - change or clean your bearings
Diff might need to be rebuilt