Bad vibration and shake after changing LCA

[Tinman]

Hi, I have recently refresh most of my suspensions components, At first all shocks and springs were replaced, for the front I went with new oem shocks and springs, same as what in my car except i went with powerflex purple mount. For the rear, original shock was 6C0513025AH and spring 6Q0511115CD, this was replaced with 6C0513025AJ shock and 6Q0511115CK spring. The rear was slightly lower, and firmer, ride comfort about the same as before.

After a few weeks of settling, the front control arms, ball joints, stabiliser links and arb bushes was replaced. Cupra LCA with the solid rear bush, oem ball joints, meyle hd stabiliser links and powerflex purple arb bushes were the new components. The handling of the car has greatly improved with those change however i get this rubbing noise when turning the steering wheel at idle or at very low speed (less than 5mph). This was not my main problem, its the very bad vibration and shaking i get when going from higher rpm to lower rpm (less than 1600rpm) and back to higher rpm. From idle to higher rpm, there is no problem. Anyone got any idea whats cause the vibration and shake?

I didnt installed the components myself, ive brought most compoents myself and paid the mechanics for the labour work. The only think i was not sure was part number for the anti roll bar, i had brought all 3 size bushes and the 2 size brackets, i measure the diameter of the bar with the caliper reaching the bar from the engine bay, took few measurements, all comes to 19mm. I also test the 18mm and 19mm arb bush on the bar again reaching from the engine bay, the 18mm arb bush leave a big gap and the 19mm just about see the gap so i choose 19mm as my bushes.

[spartacus68]

Can should be tight as a drum, however that might just be the issue. Swapping out original rubber bushes for Powerflex mounts is going to give a potentially tighter feel all round, instead of comfort over uneven roads. I think you should probably look at engine and gearbox mounts - that's the only thing I can think of if engine is running fine on tick-over or under load.

Regards rubbing noise - there shouldn't be, especially if everything is within specification. Surely the mechanic would see if ARB bushes weren't sitting right? If there's any marks on the ARB - assuming there's no movement?

[Tinman]

The mechanic had a look at it aleast for the rubbing or poping noise probably the better description when wheel is turning is the broken strut bearing on the driver side, they replace the bearing but same thing happen when they did a test, new bearing broken They investigate further, saying something not sitting probably in the middle or the some piece of spring edge may have broken off, they are ordering a new spring to compare. If its the spring thats bad as those were less than 6 months old

[RUM4MO]

What brand of spring was fitted back then, and was that work just to replace a broken spring?

I always replace the top mounting and bearing when or if needing to replace a front spring on my cars - doing that saves time going forward, but might cost a bit more.

[Tinman]

They was talking rubbish spring is fine, bearing got 2 hairline crack on the metal at the top, they replaced it and also replaced the spring cup. I did tell the mechanic dont used the old bearing, bolt and nut when i got the front struts which was same oem as old stuct done. No more noise when turning.

I will looking into gearbox mount and the dog bone mount next, hopefully replace those with better mount will solve the excessive vibration and shake.