NC: Rear Suspension Ball Joint Failure

JBT · Postby **JBT** » Tue Feb 14, 2017 2:36 pm

I am trying to gauge how common is the occurrence of NC rear suspension ball joint failure. There are four each side. If you've experienced this, please be kind enough to respond with:

1. Km travelled
2. Which link
3. How detected

bruce · Postby **bruce** » Tue Feb 14, 2017 3:17 pm

Is this the answer to your Tein problem?

JBT · Postby **JBT** » Tue Feb 14, 2017 3:35 pm

Been thrown up as a possible suspect. Too many coincidences and no visible signs of failure so, I remain extremely sceptical. I'm interested so see the failure rate as I've never heard of one going.

Shadgrind · Postby **Shadgrind** » Tue Feb 14, 2017 5:46 pm

Ball joints? Didn't know they used them on mx5s, lower and upper wishbones? They just don't fail do they?

JBT · Postby **JBT** » Tue Feb 14, 2017 6:33 pm

Shadgrind wrote:Didn't know they used them on mx5s, lower and upper wishbones?

.
You won't find upper and lower wishbones on the rear of the ND either.

Shadgrind · Postby **Shadgrind** » Tue Feb 14, 2017 8:50 pm

?

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Luke · Postby **Luke** » Tue Feb 14, 2017 10:17 pm

I have not heard of them failing, it never comes up as a topic of discussion at track days. NC owners just seem to have issues with gearbox selectors, coil pack signal leads snapping and coolant header tanks cracking.

Are the rubber boots all intact?

Here is a link to the big forums discussing rear ball joints.
There is a post in there that has all the part numbers for NC's as well as the stronger RX8 parts. It seems you would have to order each arm as the ball joint is part of them. Pricey.
https://forum.miata.net/vb/showthread.php?t=526216

JBT · Postby **JBT** » Wed Feb 15, 2017 12:44 pm

Thanks Luke, yes saw that thread on Miata.net. Luckily, I haven't had any of those other issues the guys down your way have had...yet.

I don't recall ever seeing any of the ball joint boots damaged - yes I do hand clean the suspension every 6 months or so. I was told all the boots are intact but, two upper ball joints on the right are "rough" and could be a noise source.

Still beats me how a noise that was never there, can start on the left, then cease on the left and move to the right in the space of a few days....and now one or two ball joints are suddenly suspected of causing the noise. Have the coilovers killed my RHS rear ball joints?

I'm waiting to wake up from this nightmare..... :roll:

JBT · Postby **JBT** » Wed Feb 15, 2017 8:30 pm

Spot the mods - apart from the coilover.

Right Rear.JPG

Luke · Postby **Luke** » Wed Feb 15, 2017 10:27 pm

I'm gonna cheat and say grease nipples as per the other thread.
Oh and sway bar plus worn down R-specs.
Now that you have posted that, it looks like you still have the standard sway bar links. Depending on how much you have lowered the car you may want to look into adjustable links to correct the geometry of them.

JBT · Postby **JBT** » Thu Feb 16, 2017 5:55 am

Winner!

Tyres are OK, that's a sidewall you can see. Sway bar links are OK for my purposes ATM. I'll consider shorter/adjustable ones when they need replacing - or if a bargain buy comes up before then. :wink:

Charlie Brown · Postby **Charlie Brown** » Thu Feb 16, 2017 3:34 pm

John,
A bit late on the response but I don't get on here much now-a-days.
I had a bad thud from the right rear about 15 months ago. Didn't happen on every bump, just some.
Ended up being the inner leading bolt on the bottom "trailing" arm. It felt tight with a normal socket wrench but it took 1/8th of a turn with a breaker bar where the other bolts/nuts didn't move.
Fixed the problem.
I know that you said all bolts were tight but give it a go.
Cheers
Phil

JBT · Postby **JBT** » Thu Feb 16, 2017 8:07 pm

Thanks Phil, they were all tight as. Used a breaker bar too but I could be getting feeble with age. The workshop went over them all again too before pulling the coilovers for dyno testing.

The ball joints were not supposed to be greased but, there was a comms breakdown and it happened anyway. I have been provided with a full set of links with excellent ball joints from a car with similar km and an offer to swap them in if required. Rather than undo everything that had been done, I elected to continue with the greased joints for now...what could possibly go wrong :?:

I've run up 100 km over the local cr@p roads and the suspension is silent.

Could be placebo effect but, I think it feels smoother in general and no longer "crashy" over more severe road surface imperfections.

I'm doing a Club run final recce on Saturday which should really sort it out. To be continued...

JBT · Postby **JBT** » Sat Feb 18, 2017 6:06 pm

Ran up 350 km today including some pretty rough stuff. That's 500+ km since the job was done. No noise except hard arrivals at the bump stop. So, I'll call this case closed.

NC owners - CHECK YOUR BALLS!