Ohlins MP20 knocking noise
 

[ame="https://www.youtube.com/watch?v=hQH3ZgVeHho"]Öhlins DFV knocking noise - YouTube[/ame]

this is the description under the video:
Car: Toyota 86
Shocks : Öhlins Road and Track DFV SUSMP20 F:4kg/R:3kg
Camber Tops: Raceseng CasCam
Endlinks: Whiteline
Tyres: Potenza RE003 (30PSI cold)
Preload: F: 32mm (recommended setting)

This is a nightmare!!! Absolutely killing me whenever i drive the car. The noise is driving me nuts. Cannot live with it. Have been spending all of my dayoffs since the initial installation, trying all sort of ways to figure out the source of knocking noise over sharp bumps in low speed from front struts. I can literally hear EVERY bump on the road through the cabin. Replaced another set of camber tops, another set of lower balljoints and swaybar endlinks. Changed the upper spring perch to Raceseng bearing perch to eliminate spring binding. (Recommend preload is 32mm from free length)
I'm sure the noise is coming from inside of dampers. Either running Whiteline or OEM endlinks as well i disconnected them, the noise still exist. I don't believe that's the way DFV works. Whenever i try to push the car it makes me worry and panic it could make further damage.

Emailed to Öhlins Sweden, they even sent another pair of front struts as replacement. But it's not making any difference. Super frustrating and annoying. Been spending lots of time and money just on this single issue. Had very high expectation on Öhlins but not expecting coilovers worth $3200AUD makes noise.
Noise started from initial installation. Isn't going away on any damper setting.

If anyone have experienced similar issue please share.

PS: May have to crank up the volume to hear the knocking noise. Microphone is mounted inside of cabin on the dashboard.

Long story short, got a set of MP20, already found knocking noise right after initial installation. After some researching, i don't think it's something normal. Contacted Ohlins Sweden, they immediately sent me replacement. But the noise was exactly same as original ones. I thougth it's the camber tops. Then i got a set of Raceseng Cascam tops. the noise didn't going away. Ohlins sent me 'another' pair of front dampers. Alright this is the second pair, the noise is slight quieter but it's still there. I can definitely hear from cabin. Before the sent the second replacement, they confirmed there's no noise with those campers. (well it's not true) the noise is just not as bad as original and first replacement.

Have asked lots of ppl experienced similar noise on their coilovers. most of them found the top nuts were loose or the 4 bolts around the shaft not installed properly. I have checked dozen times. that's not the cause in my case.

I have done the followings:
torqued the top nut to recommended spec
disconnected swaybar, removed endlinks
torqued every single bolts attached to the damper
checked the tower braces are tighten
replaced lower ball joints

At the end i swapped a pair of no brand coilovers from my friend and the noise gone. So i'm 100% sure the noise is coming from dampers itself.

I'm appreciated the warranty claim from Ohlins Sweden, but that's doesn't solve the problem.

Super frustrating and annoyed whenever i drive the car. Been spending too much time and money just to find out the problem.

The only way you can be 100% sure the noise is coming from the shocks is to take them to a shop that has the ability to dyno the shock, and have them run it on a machine. Otherwise, it's just speculation, especially since you were sent two sets of dampers.

-alex

My friend has these installed with another company's top camber plates, and they are clunky/noisy as well. It's the camber plates in his though. They use spherical balls with no bushing, and if you take the weight off the wheel by jacking the car up off the ground, you can move the top of the shock and feel/hear it moving just a micro millimeter inside the camber plate. Good luck with yours! :/

My God! You're driving on the wrong side of the road!

I spent the entire video searching for utes. I only saw one. WTF? You call that Oz?

I suggest you life the car, take the wheel off, and shake like mad, trying to get something to move. Something IS moving.

BTW I listened to your video.

The sound is not coming from the shock, it's coming from your upper mounts.

An improperly sized shock nut can do that. So can one that is not tightened properly.

I've heard this noise on various cars over the past 20 years. The solution is always the same.
Pillowball upper mount is loose, from one of the two reasons above.

-alex

Are you using the Öhlins or Raceseng spring perch? It's important that the bushing between the shaft, upper mount, and perch is properly sized. Raceseng makes a number of bushings to accommodate different coilovers - it's possible that when you ordered your Raceseng CasCam plates you selected the incorrect size bushing, which may be causing the noise. It's relatively easy to verify.

The spring perch and bushing (spacer) from Raceseng for Ohlins Road and Track specifically. And it's snug fit to the shaft, absolutely no movement around the shaft.

The new MP kit dont come with camber tops anymore, that's the reason the price comes down alot. First pair of camber tops from local suspension shop (MCA). I thought that's the cause of noise so i ordered Raceseng camber tops with spring perch and everything. But noise is EXACTLY the same. Initial installation was done by a shop specialise in 86. Also, both pairs of camber tops are brand new.

Did you try the OEM tops?

The probability of the the dampers themselves making a knocking sound are is probably -1... It is almost certainly in how the Ohlin's mate to the top mount (as other have noted).

Apart from the noise, how do they feel?

Best way to know, put back the OEM tops.
The MP20 can re-use the OEM rubber tops.

If noise goes away, its the raceseng plates.
If it still persist, swap out the endlinks to stock ones, rinse and repeat.

Do this until the only factor left, is the dampers...

I'm running CL Brakes and the way they are made, they have some up and down play, and sometimes make noise on bumps. It also makes noise when I reverse as the pads are getting picked up by the rotor and fall back down.

Maybe this is your issue?

Andy

Preload or strut mount

yes, this is the last option. I don't have spring compressor. I might have to give it a try anyway. Just scacrificing camber is not what i want.


Preload is 32mm front, which is recommeded setting and way above normal preload setting. Even 2mm of preload the spring should not move when the car is off the ground.

I had a similar knock and found that one of the lower bolts which mount the shock internals into the strut body was not torqued. This is the bolt which has the rebound adjuster running through it, in the bottom of the shock body. It takes a 19mm deep socket to reach it over the adjuster. I guessed at 35 ft/pounds as a torque wrench setting and one side clicked at that setting, and the other went almost 1/4 turn before reaching that torque.

I went through a lot of other things first, like many others have...

You should be able to reach this bolt without lifting the car. Turn the steering all the way to the right to access the left side from behind the wheel and then turn the steering to the left to access the right side.

Too bad that it comes under-torqued from the factory. Did they outsource the manufacturing of these coilovers? I installed recently a Sachs performance coilover and did not have any issues at all. No knocks or strange sounds and suspension works perfectly.