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Had Tein Flex Z fitted in May 16. 7,000 km later (started at 5,000 km) I've got a random 'knock' from each side of the rear on suspension compression but, nowhere near the bump stops. Doesn't matter if the car is loaded with two and weekend luggage or with one up.

Happens over small bumps and dips which are barely noticed in the Mazda6 - so not sharp or very deep/high. Tried damper settings all through the range and only full hard (a back breaker) seems to stop it. Been back to the installers twice - no fix. It's going back again Monday. Been over everything - all the suspension nuts and bolts are tight and the coilovers are set as per Tein's instructions.

I suspect damper internal failure. Anyone else having this issue or got any ideas?

Do a goggle search and you will find it is a common problem. My Teins are old and one corner knocks. I'd like to put them in the bin.

bruce wrote:I'd like to put them in the bin.

Ditto.

This is not just Teins. This is common on a lot of coilovers.
A lot of coilover systems use pillow balls instead of rubber top mounts. This means metal on metal contact.
The springs also sit on metal perches where as normal suspension parts have rubber insulators between the springs and perches.
And the mounting bushings are usually a hard material instead of rubber.
You will get noise and vibrations that were not in the standard setup.

There are lot of people out there that should go for lowering springs and possibly better shocks.
I have talked to a lot of people that complain about their coilovers and I believe they are seriously misguided by forums, sellers and manufacturers.
Even my sisters boyfriend who uses his 86 as a daily car wouldn't believe me as the forums and manufacturers said they are good for everyday driving and has learnt the hard way as his HSD's are make knocking noises.
In the end of the day a lot coilover systems are aimed at racing. There are some out there that are comfortable but are very pricey. Manufacturers can put street performance or any other marketing spin on it but in the end of the day they will never be as comfortable or quiet as a good set of shocks and springs.

Yes, with the benefit of 20/20 hindsight, there is probably a lot of truth in that Luke. No pillow ball top mounts used on this setup - they just bolt in to the original places and the springs have a fibre thrust washer on the lower perch. The springs are under tension, even at full droop so, should not be making a random noise on medium compression. However, if the dampers are failing internally... The agents aren't writing it off as 'normal' so we'll see what happens next week.

Thing is, nobody talks about noises etc. and I specifically asked if the ride would be harsh or travel limited. I was assured it would be firm but compliant with normal travel. I'm happy with how the suspension performs and think it may improve if I go back to standard anti-roll bars. This 'knock' noise though...

There are lot of people out there that should go for lowering springs and possibly better shocks.

Yep, I'm one of them and was going to go that way but, because there are so many combinations, thought I'd take the ride height adjustable, packaged system made by a reputable manufacturer. Hmmm...

Most common mistake with coilovers is expectations!

Common off the shelf coilovers (in general) use stiffer springs to give a 'sporty' feel. Most consumers assume that stiffer is sportier, however this is not the whole story. Remember dampers do not control weight transfer, rather the speed of the weight transfer. Are there dampers critically damped for low, med, high speed bumps?

Are you running on some surfaces or 'normal' roads? Stiff springs on rough roads are brutal, however if you are wearing a harness you have less body movement hence will feel softer than a seat belt on the same road with the same dampers.

On the OP's subject I have had some tyre rubber caught in the springs causing some noise... However it appears that JBT's is a quality issue that needs to be resolved at the manufacturers level or the installer.

Luke wrote:This is not just Teins. This is common on a lot of coilovers.
A lot of coilover systems use pillow balls instead of rubber top mounts. This means metal on metal contact.
The springs also sit on metal perches where as normal suspension parts have rubber insulators between the springs and perches.

Well you can rule out pillowballs on any mx5 coilover.

I have had seven different branded coilovers in various cars. All came with rubber on the spring head and perch. If they are missing. Then they are an old set of used coilovers. And no wonder they are clunking.

The biggest problem with coilovers is buyers get too high spring rate for street. Preload being incorrectly set is also another huge issue. You'll be surprized how many mechanic cannot set coilovers up right. I personally have no issues with coilovers. And I'll doubt I will in the future.

It if you want your car just to be an A to B car or an grand-tourer, then coilovers aren't for you.

I agree all around. There is metal on metal contact in coil overs. After some kays, the metal wears allowing play which causes noises.
I will probably go back to shocks and lowering springs.

What will happen is they will tighten up the collars and maybe put in some insulating material. Give it a few thousand kays and the noise will return..

project.r.racing wrote:All came with rubber on the spring head and perch. If they are missing. Then they are an old set of used coilovers. And no wonder they are clunking.

These were new 9 months ago. The Flex Z parts breakdown does not show an upper seat rubber. The lower perch thrust washers are there. I don't think this has anything to do with the springs. I suspect a damper internal component problem. It is also possible, but unlikely, that it's something to do with the damper top mount collar/bush arrangement.

Went out today for a 20 km drive over typical cr@p roads in the area and it only happened twice - always when you least expect and over a dip/bump that you didn't even see.

This was always happening on the left side. After they had the car for three days it is now on the right...hmmmm...

They probably swapped the shock over.
The noise tends to come from left rear as it is the unweighted side (non-driver side).

They probably swapped the shock over

That has been a nagging thought.
Oddly enough, when it occurred most on the left side, it was with a passenger in the left seat.

project.r.racing wrote:Well you can rule out pillowballs on any mx5 coilover.
I have had seven different branded coilovers in various cars. All came with rubber on the spring head and perch. If they are missing. Then they are an old set of used coilovers. And no wonder they are clunking.

The biggest problem with coilovers is buyers get too high spring rate for street. Preload being incorrectly set is also another huge issue. You'll be surprized how many mechanic cannot set coilovers up right. I personally have no issues with coilovers. And I'll doubt I will in the future.

It if you want your car just to be an A to B car or an grand-tourer, then coilovers aren't for you.

Your not confusing adjustable upper Camber/Caster plates which use pillow balls with fixed position pillow balls?
My Tein Street Flex on my NB uses a fixed setup which I'm sure are pillow balls, at least Tein say they are. No rubber upper mounts. All metal on metal contact.

I bought brand new and no rubber came with them for the springs to sit on nor does it show it in the parts breakdown manual as per JBT's comment as well. Metal on Metal.
Toyota 86 HSD's were the same. Metal on Metal.
But yes there are some units out there I have seen with rubber insulators.

Good points on what coilovers should not be used for.
I'll add to that if you are just after looks of lowering, than they are not for you as well. Lowering springs and optional shocks for that.
It is more work to install springs and shocks as it generally requires utilising parts of the existing strut setup, but ride quality will be far superior to most coilovers.
There are plenty of options for any generation MX-5.

@ JBT
Good luck with the noise issue. Don't be surprised if the supplier doesn't find a permanent fix. My Street Flex made noises early on as well.
As you said NC's do use rubber top mounts for Tein products so that shouldn't be an issue.
Then again the rear end of my AU IRS Falcon had Rubber mounts and the shocks eventually(130000kms) elongated the centre holes which did have a metal inner sleeve. This then made knocking noises as the shock moved around in it. Common AU Falcon related issue, new top mounts were the fix. I doubt that would be your issue being so new and I'm sure its better quality than Falcon parts. Only car in the family that ever had this issue.

Do you use the car for any track work?
If you do I would keep the coilovers and live with the knocking noises.
If not it us up to you wether you can live with the noise as I don't think it will go away permanently.

Yes, the car is and has been used all its life for motorsport, club activities etc. however, I'll be doing less motorsport this year because I'm taking a bit of a break. Now that I have the dampers set to my preference for street driving at 8 clicks (half way) all round, I am delighted with the way the car feels and grips over all sorts of road surfaces.

A club friend has had Teins in his NC for the last 100,000 km with no noises. I will not accept this noise as 'normal'. Did 250+ km on a club run today, including rough goat tracks such as Dayboro to Mt Mee and down Campbell's Pocket Rd. That random knock from the right rear (which used to come from the left rear) drove me nuuuts!!

I have pretty much nailed the conditions down now to fast rate, slight to medium strength compressions. The sound is a metallic "tok" noise. Definitely does not happen during heavy or full compression to the bump stop nor on rebound, regardless of the rate of onset. So, to tomorrow....

Luke wrote:

project.r.racing wrote:Well you can rule out pillowballs on any mx5 coilover.
I have had seven different branded coilovers in various cars. All came with rubber on the spring head and perch. If they are missing. Then they are an old set of used coilovers. And no wonder they are clunking.

The biggest problem with coilovers is buyers get too high spring rate for street. Preload being incorrectly set is also another huge issue. You'll be surprized how many mechanic cannot set coilovers up right. I personally have no issues with coilovers. And I'll doubt I will in the future.

It if you want your car just to be an A to B car or an grand-tourer, then coilovers aren't for you.

Your not confusing adjustable upper Camber/Caster plates which use pillow balls with fixed position pillow balls?
My Tein Street Flex on my NB uses a fixed setup which I'm sure are pillow balls, at least Tein say they are. No rubber upper mounts. All metal on metal contact.

I'll take a photo of you fixed ball upper mounts any time to prove myself wrong.