Upper balljoint on NAs and NBs

[kevinharrop]

Hey guys,

Haynes says that the upper balljoint on the front suspension cannot be replaced by itself, but that the whole A arm must be replaced.

True?

[JamieH]

False.

The upper ball joints can be pressed out and replaced. BUT...

What is available from the aftermarket has a caveat. What you want is the MOOG K500210, but it is only advertised to fit the NA, even though it will press into the NB control arm. If used on an NB, it will not reach far enough through the NB knuckle for the cotter pin to slip in. If you were to use NA knuckles on an NB, even if using NB upper control arms, it would work. But, then you are throwing out the reduced bump steer of the NB knuckles.

On the bright side, the MOOG K500210 works fantastically in NAs, regardless of NA or NB upper control arms being used.

I am uncertain if there is an aftermarket NB specific upper ball joint replacement option.

[kevinharrop]

Does not sound good.

Is the upper A arm available with the balljoint in place?

[JamieH]

Yep.

https://www.jimellismazdaparts.com/products/ARM-ASSEMBLY/1899311/N06834250.html

Part# N06834250

Though, to save a bit of coin, the common practice is to buy low mileage, good condition used arms. Check with the known Miata parts breakers.

[kung fu jesus]

Our friends at V8 Roadsters have a solution, check it out:

https://v8roadsters.com/product/front-upper-ball-joint/