Front suspension failing inspection

[SteveS]

Hello everyone,

I failed inspection (2007 MN) due to a leaking front shock absorber, got two new shocks and it failed again.
The way it's done here: put the car on a vibrating plate, measure suspension oscillations then compare each side to the vibrating plate, and the two sides against each other, must fit within a threshold. With my car, the phase difference to the vibrating plate is too small, but the difference between left and right too large. Should be the other way around to pass.

Normally, this issue is found on the rear suspension of light passenger cars, this is also reflected in the local forums where I can't find a car similar to mine with this issue.
The drop links of the anti roll bar and the silent blocks have also been changed recently.
Front wheel alignment hasn't been yet done after the shock absorber swap, the rear left hangs a bit lower than the right, but not sure whether these could be part of the problem.

Help?

[SteveS]

I just got this sorted out. Upon closer inspection, the new shock absorbers were both leaking, barely driven on them. Got two new TRW shocks and Sachs springs, got through the inspection without issue.

[Longranger1]

Just going through the process of overhauling the suspension on my son's recently acquired 2008 ml to get it up to a decent standard for the rwc. One thing I've found from other folk's experiences is that cheap components are just not worth it for durability and safety.
I am running a combination of Dobinsons coils, EFS 150kg rear springs and Superior Engineering shocks all round. Also, new upper and lower ball joints and tie rod ends. I run Superior's rear shocks on my MN and they are are big step up from Ultimates I had previously. My front struts will eventually be replaced with that brand as well. Putting the struts side by side as in Ultimate vs. Superior Engineerings product there is a big difference in quality and shaft size, shock piston size and oil volume. Ultimate do supply a decent spring package though. If my experience on my own mn is to go by, the ride on the young bloke's ml should be excellent.