So, When you say a metallic bonk exiting the speed bump...... at the back, do you mean the back of the car? Ten inch high bump is really going to hit the car underneath, its only got 4" clearance under there! If you are somehow getting overt I'd say the rear chassis member/exhaust are hitting it as the wheels come off the hump.
Got a new computer and can access your pictures fully now.... gadzooks! your SSL set up is all wrong. It's hard to get the full story but apart from incorrect fitting the collet adjusters have made no spring preload adjustment whatsoever. In effect your sliding hub is free to move where it wants with no spring involvement. The main spring and rebound spring are meant to work together so at ride height and under load the main and rebound springs should be either side of the hub, in effect touching the hub seating surfaces. I'm not sure I believe the trotted out belief that you should be able to rotate the rebound spring with the car sitting under load, wheels on the ground, this I feel is a ridiculous way to show that the main spring load is set at rest with the hub sitting supported between the two springs! This will give the softest spring setting. You should have two adjusting C spanners to set and lock the suspension load? And again there is no evidence of the hubs having been greased! Have you got the installation instructions? And I wonder how many bits your fitter didn't think he needed to use.
So, let's get the relevant points laid down here shall we.
The main spring....... in the SSL or suplex system as it was formally called, This spring is a progressive rate spring and has an initially softer response which allows the suspension to absorb the bobbly irregularities of the road surface where a standard spring would just transfer the shock straight to the chassis. Then when asked to absorb a greater shock the stronger element of the spring comes into play. at this point the sliding hub will leave the seat of the rebound spring as it travels up the fixed pin. When the hub returns to normal ride position it is damped by the rebound spring.
Rebound spring....... beyond the above involvement of the rebound spring in the suspensions travel it also keeps the wheel from dropping into holes in the road and damps this movement preventing the obvious issues.
Spring loading........ So as we have ascertained using the previously described setting for the spring loading, this will give the softest setting, what if you want to stiffen up the suspension.... well your rebound spring ain't going to rotate freely by hand now! Yet your suspension will still be working between the main and rebound spring for most of its critical movement. This suspension system was designed as a self damping system and in fact HFC or harry Morgan didn't design it to have shock absorbers fitted but that's another story! But if you were track racing on a smooth surface you would have selected a stiffer setting and your hub would probably never lose contact with the rebound spring!
Firstly you will need the paperwork that came with the set up and you will need to assemble the system as per the instructions. Fortunately the adjustable element of the SSL system makes it much safer to work on the suspension as you can take the load out of the springs by backing the adjuster rings fully off, not something you cannot do with standard length springs .but can I suggest that you have a look at a site called gomog and read the suspension service section as this will help you understand the system better and show you how to work on it safely. When you have the system fully disassembled check the play of the pin in the hub, Ideally you don't want any but the smallest micro movement is acceptable. If you have issues here come back to us and we can address that for you if needed. And finally, you must understand fully the function of a suspension system and just how dangerous it can be to work on, springs under compression can be lethal and if you have no knowledge of how the system works you should not attempt to carry any work out yourself.
