Knocking coilovers. HELP!!

Hi everyone,

fitted my coilovers last weekend, for the first day and a half they were fine, but then after that and till now they are knocking a good bit while steering after a half round turn of the steering wheel and as far as full lock.

btw its only the front, the rears are fine.

it sounds like the spring moving as a spring has a quite a distinctive sound. its not like something hitting something. its more like the spring been held at one end and then and letting the other end turn and then quickly releasing the end that was held.
checked them all over and no signs of damage or wear to any components, covered the top and bottom in gear grease and still happening

any help or suggestions much appreciated, thanks

Are they new coilovers ? Knocking shocks on Subarus will be the death of me

yup brand new

i heard its a plague in scoobys alright

They are a plague in standard suspension but shouldnt be in coilovers. What make are they ? I've heard of K-Sports knocking.

I think what you are describing is called stiction. I have BC Racing coilovers and I notice when going around the small roundabouts sometimes I get knocking sounds coming from rear coilovers, nothing at all ever from front. I thought it might be muck build up on the spring seats causing failure of the upper bearing mount and so the spring holds still as it compresses and then suddenly releases at some point of pressure (like and earthquake does). I was going to remove them and clean them when i get a chance and see if that made any difference.

See below from BC Racing specs page for explanation:


"Bearing mounted upper spring platform:
Because the spring twists as it compresses it is very important to minimise stiction between the spring and its seats. If this tension is not relieved then spring binding can occur leading to the spring rate effectively altering slightly as the spring compresses and extends. The tension generated can lead to rapid deterioration of the spring pearches and in extreme cases can cause the spring platform and locking collars to loosen. This can lead to the platform and locking collars ‘walking’ down the damper resulting in un even ride height and danger of the spring dislocating under full damper extension.

The friction between spring and seats also has an effect on steering effort as the springs are physically turned with the wheels. This introduces additional unnecessary friction into the steering system which has a knock on detrimental effect on the vehicles handling characteristics.

The bearing mounted upper spring platform is one of BC Racings innovative designs. By vastly reducing stiction between the spring and its seats the BC Racing units avoid the above problems thus improving the efficiency of the steering system and allowing the spring and damper to work as designed."

they are MDU pro logic racing coilovers.

yeah i think it is what you have described there, the sudden release of spring tension when steering, it doesnt sound good

however it couldnt possibly be much or grit in my case as they are only on a week,

is there a way to prevent the spring from gripping what ever mount it is gripping when i steer, OR do i try and get the spring to grip it even more so it wont slip at all, which way do they generally work?

sorry for what are probably stupid questions

These is it?

http://www.mdusport.com/subaru.html

Never heard of that brand myself... were they cheap?

Suppose you could try grease between where the springs and spring seats meet to try and reduce stiction - you would have to loosen them first or use spring compressor (i got these in Halfords). Might try it myself at the back some time

Recently changed the rear shock in my wagon,.

Found that when i put them on, it kept knocking and banging every so often.

I released the tightness a bit and now happy days, no knocking at all.

Might be worth a go.

yup similar to those alright with damper adjustment

yeah thats not a bad idea actually possibly just too much tension on the spring, it is only the front for me though, strange that all other examples are rear complaints



how much did you release the tightness by if you dont mind me asking murto?

Mine were pretty tight, released the nut a couple of turns,

so it was just tight(if you know what i mean). Then took the car for a spin.

Went over a few speed bumps and a round about. No knocks bangs or popping since.

Also checked the nut on the thread, no movement. So far so good.