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I've got Koni yellows on my car installed by previous owner. Over time it's developed a wicked squeak and I've finally found the culprit as being the top of the shock under the rubber hat rubbing the body causing metal on metal friction.
I have never taken the suspension apart on these cars, but assume it's pretty standard. is this something that is just a matter of re-aligning or worse?
I know the answer is take it apart and look, which I will do next week but it's on my mind so figured I'd ask
3 things come to mind.
1. in your pics, i'm seeing wetness that appears to originate from the shock and drip down. Makes me wonder if the shock blew a seal and needs rebuild / replace.
2. there is supposed to be a thin, mylar, plastic sheet, gasket looking thing that is supposed to sit between the upper shock mount and to body to eliminate squeaks. Yours might be missing. Here's a pic of it in a Miata for reference https://forum.miata.net/vb/showthread.php?p=10778482
3. you can try repositioning the shock shaft so it is not against the unibody but I don't think that is the cause of a squeak. I could be wrong of course but go ahead and try it and let us know.
3 things come to mind. 1. in your pics, i'm seeing wetness that appears to originate from the shock and drip down. Makes me wonder if the shock blew a seal and needs rebuild / replace. 2. there is supposed to be a thin, mylar, plastic sheet, gasket looking thing that is supposed to sit between the upper shock mount and to body to eliminate squeaks. Yours might be missing. Here's a pic of it in a Miata for reference https://forum.miata.net/vb/showthread.php?p=10778482 3. you can try repositioning the shock shaft so it is not against the unibody but I don't think that is the cause of a squeak. I could be wrong of course but go ahead and try it and let us know.
1. That wetness may be from me spraying wd-40 trying to find the squeak, but I will definitely check again when I pull it apart.
2. That link doesn't have a photo unfortunately, but I suspect I am missing it. I just have the rubber boot on top of the hat, no gasket I can see at least from above.
3. That is definitely my next step. I'm hoping it's just metal on metal but it will be easy enough to test.
Identical except it doesn't rest against the metal, it's aligned right in the center.
I'll take it all apart either tonight or next Tuesday and see what's what. Thanks all for giving me some suggestion on where to start! I've installed shocks/springs before but have never had any actual fail or cause issues.
I wonder if there's some wear/reeming out in the upper mount that would allow the shock shaft to sit a little off center relative to the three studs that mount it. In aftermarket upper hats, that's a bearing, but in the stock if I recall it's rubber.
I wonder if there's some wear/reeming out in the upper mount that would allow the shock shaft to sit a little off center relative to the three studs that mount it. In aftermarket upper hats, that's a bearing, but in the stock if I recall it's rubber.
OP should jack the car up and down and see if the shaft doesn't move...
Alrighty I took it apart last week. Couple things.
1. The gasket is 100% missing, so I got some rubber hose and made some little spacers while I find and order gaskets.
2. The alignment of the shock was fixed by using a spring compressor and "hand aligning" the center of the strut with the rubber spacer/grommet up top. To be honest I was a bit let down by how flimsy it was on my Koni yellows. There is nothing that keeps the alignment in place without the spring pressure, so it would seem they were misaligned out of the factory.
Bonus question, now that I'm here. I have Koni yellow shocks and Tein S springs....and tbh the ride is a bit harsh for my liking. Is there a spring out there (maybe Tein H or something not so lowered?) that anyone has experience with for a more moderate, softer ride? I know I can throw money at the problem with coilovers, but these shocks/springs only have ~6k miles on em so if there is a cheaper way I'm interested.
I get these are sports cars but I get a free chiropractic adjustment when I hit speed bumps with my current setup
Thanks again everyone for the thoughts and advice! wonky alignment if shock through tophat more wonk temporary fix for missing gasket "Fixed alignment", after aligning the shock by hand with spring compressor
Those are the Tein H Tech springs (gold) - so ride height will be higher than the S Tech (green). I used to run the H Tech with Konis on my car.
Post a pic of the lower spring perch on both rear shocks
Post a pic of the shock shaft showing the rubber bump stop
Which of the 3 ride height settings are the spring perches set on?
The problem with a standard shock and spring setup on the FD is that it reuses the OE upper shock mounts which have a very hard rubber bump stop built into them. Same design as the first generation Miata with the same outcome when lowered - insufficient shock travel with a hard bump stop delivers a hard ride when the shock bottoms out against the bump stop. A solution to that for the FD is the same as the Miata - remove the OE rubber pucks and install aftermarket foam bump stops like the Fat Cat bump stops. I posted about that a number of years ago.
Not sure if rubber will eliminate the squeaks. Mylar is very smooth like a teflon coating which helps eliminate the squeaks. Guess we'll find out if it works soon enough.
Below the only other pics I took of the rear left shock removed from the car if that helps.
Yeah the rubber was just me messing around, I am actively looking to buy the gaskets and based on your advice maybe some replacement bumpstops, or even these Ohlin top hats?
Everywhere I read people recommend the full Ohlin DFV setup, but I imagine these top-hats will work with any shock... And with my car being mostly road-driven I just wanna make it livable and fun to drive.
Btw @gracer7-rx7 , thanks again for the knowledge! I see you have been helping people with FD suspension here for like 15+ years now, appreciate your advice.
You might want to consider replacing the bump stops like I did to improve ride quality. I commented on solid upper shock mounts in that thread as well. YMMV based on your preferences of course...
The spring perch looks like it is oriented correctly in your pic. Sometimes people install them upside down which will affect ride height.
Take a close look under the perches and see which of the 3 settings they are installed in. I just searched my old posts in the Suspension section and I used to run it in the middle perch with those springs and shocks.
If you want to use the ohlins top hats, you'll have to determine the inner diameter of the spherical bearing that locates the "shock pin" on the damper and compare it with the outer diameter of said shock pin. IIRC the ID on those is 12mm, but you should probably confirm with a vendor. I had to have a spacer made to locate my penske 8100 dampers to a cusco top hat that secures with a jam nut, which isn't too much trouble given you have access to a lathe.
+1 on the bump stops, it just makes the miatas work.
part two is that those shocks have some adjustment, you might try it. you ideally set them to full soft, go for a run, full hard go for a run, and then the middle and go for a run.
the full soft and full hard calibrate the butt dyno, so when you're in the middle you know which way to go. the full hard run can be really short, like a turn or two.
Yeah I have em adjusted about 1/4 turn from soft. The travel in the shock feels great, it's when they bottom out that I get the spine adjustments and my wife wishes we were in her car. Sounds like bump stops are an easy first step, as eventually I am going to go Ohlins so I don't wanna break the bank on this setup.
I can't remember if we used the Miata specific bump stops but I don't think we did... I think we got some generic ones instead. I do remember cutting them to the desired length. I forgot the length though... Go to my Fat Cat thread and take a look at the pics of the bump stops to get a rough idea of length.
A bit long and rambling but... Bump stop Length is important to ride quality and suspension tuning. Too long and it will be against the shock eliminating or reducing shock stroke / compression which makes it ride rough. Better to be shorter than longer for ride comfort so that the shock can move through it's travel range and do it's job of absorbing bumps. When I had the Koni + Ground Control coilover kit, I actually experimented not having bump stops in the rear. Worked well enough but I added one back in to guard against coil bind scenarios (which I never got the rear suspension to compress enough to fully compress the rear springs / coil bind).
Long story short, get the Miata bump stops or the 5x generic foam / mcu style bump stops and cut to fit. Use my pic as reference but try to ensure that there is some sort of gap (1-2 finger width min) between the bump stop and the top of the shock so that the shock can do it's job. Shorter is better than longer imo.
