SafeTrisK

Dampener settings are all good I've had a good play with the settings over the 10k miles. Currently sitting at 12 from soft rear and 16 from soft front. A good winter set up, along with softening up the rear whiteline adjustable ARB. Takes out that slight unwanted oversteer with better rear end traction.

After going through a few things I've noticed that the coilovers would have been set with 2mm of preload out of the box.

Cheers I'll try and do this soon and report back if any improvement in handling feel has occurred.

That was quick, cheers. I'll give that a go then as I've been having some occasional strange steering symptoms for some time now. Obviously the coils have done 10k miles now, would adjusting the preload now have any adverse effects? As I understand it I have to undo the spring perch locking collar, I would then be able to take out the factory preload until there is a small amount of play in the coil. Then simply wind up the perch collar by 5mm to gain the desired preload, basically shortening the length of the coil by 5mm. Then lock off. In doing this would I then have to adjust the height as to retain the desired ride height of the vehicle?

After reading through this thread and revisiting a thread I started a while back. I think I need to make a set up change on my NC. I've had my CRD's fitted for around 15 months (10k miles). During install I never actually adjusted the preload on the springs, I only adjusted the coilovers to get the desired ride height. I was informed by misterR that the preload on the units was already preset so I did not have to carry out adjustments. Would you you recommend that I adjust the coilovers further to gain the +5mm preload on each corner from factory?

Just thought I'd give an update on the issue. I've been trying my hardest to ignore it over the summer and drive due to the great weather. The steering feel has continued to be sporadic. But I have noticed things which may be leading to something to do with the brakes. Ive noticed that the front N/S alloy wheel is becoming more contaminated with brake dust than the other side, also I've noticed a slight pull to the left particularly under light braking. Leading me to think the front N/S brake is binding slightly. The caliper was replaced for a refurbed unit 21 months (14,000 miles) ago and all front slider pins were replaced and greased only 4 months ago. The front N/S disc has a more noticeable lip compared to the opposite side. When raising the front of the vehicle I can't tell any difference when spinning the wheels. By the way no scrapping noise noted for a while. Both discs and pads have plenty of life left but the pads aren't a particularly good make. Does anybody else feel that this could be the cause of the steering issues? As I mentioned at the start of this thread that the only time I've felt poor handling similar to this is when the same caliper had seized badly. Would anybody suggest replacing the caliper again or maybe discs and pads or both as it appears if it is binding its only light as there's no difference in wheel temperature after a long journey. Cheers.

The scraping definitely didn't sound good but it didn't sound like it was coming from within the rack, maybe the universal joint or column hard to tell.

The next time I get the chance Tony I'll have to give it a go. I did notice the last time I bleed the system it did seem to take longer than usual to remove the air, level dropping in the reservoir. Also I gave it a go by manually moving the front road wheels to see if I could hear anything. All I could hear was a definite whooshing noise and also a metallic scrapping noise on every turn in both directions.

The last time I bleed the system after replacing the suction hose. With the wheels in the air engine not running there was little resistance felt when turning the steering wheel lock to lock. Then with the engine running and turning the steering wheel lock to lock there was a noticeable increase in the force required to turn the steering wheel. I didn't hold the wheel at full lock for to long so didn't notice the valve noise of the pressure being released.

I have no visual sign of any seals leaking and I'm not loosing any fluid. It may be a possibility that the seals inside the rack are leaking from the high pressure side to the low pressure side, causing a reduction in power assistance particularly when the fluid has reached a certain temperature. Not really sure how the rack and pinion works on the NC. Although the heavy steering can occur when the system hasn't run for a number of days and can revert to normal steering assistance just after a quick stop e.g petrol station.

When the steering feels normal (lighter) it feels the same no matter what speed I'm traveling. Then it becomes increasing heavier over time and the further I travel. I've recently had the geometry set @ WIM. Has improved handling under normal start up driving but the steering does become heavier. I've recently also replaced the main suction hose to the pump and this has changed nothing. I'm starting to think after much research the problem may be with the seals within the rack between the low and high pressure sides.

Yeah I can drive through the vibration so I don't think it's play within the rack. Just strange how it's at the same speed before and after the new tyres. Will get WIM to check balancing on wheels maybe, probably the fronts more so as the vibration is felt through the steering wheel.

I'm not sure if the NC has centre weighing. But the steering does require more force to perform manouvers when the wheel is near centre. But even this weight is noticeably lighter or heavier depending what mood the car is feeling in. Another thing is I've also had vibrations when driving between 80/90 mph. I though it was probably due to poor wheel balancing but having just replaced all 4 tyres along with balancing the vibration is still there. Particularly along a certain section of poorly surfaced motorway. Come to think of it that is usually just before the steering becomes heavy. Or maybe I'm just imagining things.

Thanks for getting in touch Tony. Odd to say the least. I'm tending towards mechanical myself but I'm running out of ideas to what it could be. Over on Miata.net a few where mentioning that air maybe getting into the steering system somehow, but not loosing any fluid. If this was the case the power steering fluid would appear with bubbles in the reservoir but this has never been the case as I check regularly. Also why would it all of a sudden change immediately without any steering input. I'm still thinking mechanical as when I get in the car in a morning to go to work, on starting the car you can feel wether the steering is heavy or light without even moving the car. I'm booked in next Thursday 10th @ WIM and after a 100 mile drive I'm 95% certain the steering will be @ its heaviest.

Hi No my car has normal belt driven power steering I was also thinking heating of the power steering fluid could be causing the problem. As the steering gradually gets heavier over longer journeys. But as stated this can continue when the car is sat over night or even a couple of days. The steering can then become instantly light again without a trigger I've yet to spot. I've erecently replaced all 4 tyres and regularly keep the pressures at the desired 29psi, so I don't think tyres will be having any impact. There maybe an issue within the rack, but I've performed some tests shown to me from other forums and all appears well, especially as the cars steering performs well during occasions.

I've been having an issue for some while now where the effort to move the steering has become sporadic. For example. I can set of from work for a 35 mile drive with the steering feeling light and agile. Then after a 20 minute 25 mile drive down the motorway on exiting the steering has become heavier and the handling feeling almost cumbersome. Then left the car overnight in the morning the steering still felt heavy. 10 mile drive to the petrol station for a fill up, set off and the steering has become light and agile again? I beginning to think the issue is suspension or geometry related, maybe a failing ball joint somewhere, although saying that when the steering is light it's a dream to drive on the meisterR r's. I'll try to keep this short, here is a list of things I've done to rectify the problem, but with no joy. - Replace power steering fluid and bleed. - Replace drive belt, tensioner and idle pulley. - Replace power steering pump. - Over past 18 months have replaced all calipers for reconded. - Regularly grease calliper sliders. I've brought brake calipers into the equation as the only time I've felt the heavy steering and poor handling and knew the cause was when I had the O/S/F caliper seize, replaced all was good. If anyway has had similar issues in the past and may be able to help, please do so. Luckily I've got my car book in at WIM for alignment bolt replacement and geometry in a few weeks so this issue may have some more light on it.

Hi Tony I'm aware how to change the heights I spent around 2 hours to get the ride height equal on each four corners when first installing. I was just wandering to achieve this there were slight differences in the distance between the lower locking collar and middle locking collar from one side to the other on the same axle, meaning the struts are of differing lengths.Is this ok or should I make them equal? I would only be replacing 8 of the bushes which would make it easier to locate a squeak. But as you said I don't think there is anything wrong with the bushes anyway or maybe the bolts. Just a case of an establishment trying to get more money out of customers. The same establishment who quoted me £1100 for a small rust repair on one of the rear wheel arches. Won't be using them again.

Hi Tony I will return ride height to 345mm just to gain that little more ground clearance. As the coils have settled would I need to adjust the top collar to gain the desired preload or would this not of been altered? I meant the difference between the two locking collars as I've not adjusted the top spring collar. There is just a small difference between each corner on the same axle, which is ok? I've recently been told that along with the adjuster bolts becoming seized, this has caused the bushes to become significantly worn. Would this be the case? If it is poly bushes are definitely the cheapest way forward as the only way to get hold of the OEM rubber bushes that I can find is to purchase 2 new front lower arms, 2 new rear control arms and 2 new rear link arms, which is costly. My plan was to only replace the bushes with poly that I needed to, would that have such a great impact on ride quality? What sort of maintenance do poly bushes need?

Hi I own a 2007 Mx5 NC Sport and have recently installed MeisterR Zeta CRD coilovers. On setup I wanted to achieve a ride height of 345mm and I achieved this before taking it in for a geo in the Midlands. Since then I've noticed that the ride height has lowered slightly on each corner to around 335mm. This has actually caused me to bottom out on a speed bump quite regularly. If I were to adjust the coilovers to raise the car to the desired height of 345mm would I then again have to take the car in for a alignment? I have also come to notice that to obtain an even ride height on all 4 corners, there is a difference of around 3mm from collar to collar on the front and 2.5mm on the rear. Is it advisable to have the same distance between the collars across each axle? Also at my alignment I was informed that a few of the adjustment bolts were on the verge of ceasing, so I've decided that I will be changing all 8 bolts, but not until next spring. I was also thinking of replacing the bushes that correspond to the adjustment bolts. Is it ok to change these to poly bushes whilst keeping the OEM rubber bushes in place on all other links or arms. I would say it's ok otherwise why would you be able to purchase individual sets of bushes. Obviously I will be replacing to match one side to the other. Many Thanks