Sounds like you are either suffering from bump steer (change in toe angle when the suspension moves up and down) can be caused from lowering too far or putting different wheels on. Or if it is floaty at higher speeds and you need to turn it could be worn out shocks.

Bounce the front of the car and if it rises and settles quickly shocks are all good, if it continues to bounce they may be worn out. If its the original suspension in the coupe the strut tube is just filled with oil, So under a lot of up and down it can aerate the oil making your shocks useless.

It would be hard to tell without seeing and driving the car to exactly pin point the issue, but that's a start.

The bound bump is just a bit of rubber stopping the strut from completely bottoming out.

Having some problems diagnosing a problem with my 1200 Coupe.
At highway speeds it seems to tramline over bumps and i have to counter steer to correct it and back off speed.
I adjusted the steering box, replaced sway bar rubbers, replaced castor rods and halved them to give more castor and also checked the wheel alignment (drive way job)

I cant find any movement in ball joint bearings or any steering linkages.
only movement i can find is when on jacks i can move the wheel up and down on the strut and 1/2 inch with out resistance.





What does the bound bumper do? Could this be the cause?