knock, knock - knocking sound after uprated sway bar install

[crazydriver81]

This is a question to all people, having installed uprated Cusco/Whiteline sway bars.

After installing the Cusco sway bars and new drop links (non OE items), I get an odd knocking sound from the front of my car. There was no knocking prior to the change of the sway bar, so my feeling says, it must have something to do with the new sway bars.

The sound cannot be located if left or right. We double ckecked all ball joints/tie rod, tie rod ends and they are fine. The knock is only there on light bumpy roads. Hitting a pothole or any bigger hole does not give the knock sound.

My assumption is, that the drop links are possibly a bit too long (due to not being OE items but fit the 8G range). Together with the car being a good amount lowered and the Cusco bar being thicker, my assumption is, that the sway bar is hitting the front subframe above the exhaust/prop shaft.

Can anyone confirm this? Or may there be other points to check? Anyone else who had problems with the uprated sway bars?

If it is a problem of the drop links, I will get myself a pair of whiteline, adjustable ones. But I want to have your opinions before I spend 150 EUR on something, which might not work afterwards...

[Gly]

i have the cusco items, and stock drop links and significantly lowered, no knocking noise,

you could undo the drop links and manually spin the sway bar see if it knocks, if not its something else

[crazydriver81]

good point Carsten. Will try...

[swinks]

There is little clearance between swaybars and subframes. Especially Evo 7-9 suffers this at rear. For that reason Whiteline recommends to use their own brackets. Stock brackets to subframe may be to small for uprated fat bushings.

[crazydriver81]

There is little clearance between swaybars and subframes. Especially Evo 7-9 suffers this at rear. For that reason Whiteline recommends to use their own brackets. Stock brackets to subframe may be to small for uprated fat bushings.

ok, will check that too. What bushings have you used with the cusco bars? I had them off you, so did you use poly bushes? If so, from where?

Edit: I also ordered some Prothane sway bar bushings now (22mm front and 24mm rear). For the rears I can use the bushings with the supplied brackets, for the fronts I can only use the bushings though.

[swinks]

Mine bushings were Cusco one. IIRC, they were poly one, and didn't fit with stock brackets, so we had to bend and modify brackets.

[crazydriver81]

Success! knock, knock sound has been banned. :)

It was the lateral arm left hand side front, which was torqued up under tension. We loosened it a bit, and re-torqued it according to spec and the knock was gone. On a side note, the car was only making the sound on light bumps, not when going through a pothole so it was hard to check. droplinks where new too so this could not have ben the reason either.

Further I tried to install Poly sway bar bushings. I have bought Prothane 22mm (front) ans 24mm (rear) bushings and brackets. Rears fitted without issues, but the fronts did not fit (overall dimensions were to small). So if anyone needs some 22mm universal sway bar mounts... ;)

[Mark 4]

Glad you got it sorted Stefan.