The brilliant simplicity of the suspension on a Mazda Miata has been made even better with the use of the new Penske shocks. We highlighted how to assemble the new shock packages in the March 6 release of Speed News. You can find that story HERE.

In this installment, we will highlight how to install them on the car. Like most jobs on a Miata, you’ll need a 14 mm and 17 mm sockets and spanners and a torque wrench. You’ll also need some 21 mm wrenches for the upper control arm pivot bolts, but we’re probably getting ahead of ourselves.

One of the items we always reinstall is that thin, clear plastic gasket that goes between the shock hat and the chassis. OEM engineers decided it should be on all Miatas, and it’s not clear what it’s for, but every car comes with them, so they must be there for a reason.

First, a few words on preparing the car for the installation. On the front, you will need to remove the upper control arm pivot bolt and slide it far enough forward that it gets out of the way of sliding out the upper control arm. That’s what the 21 mm wrenches are for. You don’t have to remove it, but sliding it forward is essential for being able to get the old shock out and a new one in. You’ll also need to detach the front sway bar end links at both ends so the front lower control arms can droop enough to remove the shocks from the opening in the upper control arm.

For the rear, you don’t need to remove the sway bar end links, but you do need to remove the fuel filler and evaporative hoses on the left side to be able to access and torque the bolts on top of the left rear shocks. For the front and the rear installations, you should have a floor jack on hand to be able to jack up and hold the lower control arms in place so you can thread the lower shock-mounting bolts.

If your shocks are already assembled, the job will probably take only an hour or so to complete, and the torque specs we cite are from the factory service manual. Here’s how it goes together.

This gasket that comes on top of an OEM shock hat is probably for NVH issues, so it’s probably not a bad idea to reuse them.
Drop the shock in the opening in the upper control arm and raise the upper mount into position through the holes in the chassis. Removing the upper control arm pivot bolt and sliding it forward is the easiest way to remove and replace the shock assembly.
When you get the studs through the chassis, just start the nuts. By not tightening them right away you have some “wiggle room” to be able to attach the shock to the lower control arm.
Insert the attachment bolt from the rear through the control arm and shock mount. The collars that press into the shocks with O rings can slip off if you’re not careful, so be sure they’re both in place.
Thread the nut on from the front. Trying to put the bolt in from the front won’t work. The outer tie rod is in the way. The lower torque spec is 86 foot-pounds and requires a 17 mm socket. Reattach the sway bar end link and do the other side.
Once you get the upper mount nuts snug, tighten the upper mounts with a 14 mm socket at 25 foot-pounds.
Slice the upper control arm bolt back through control arm and front subframe and torque to 100 foot-pounds.
The rear shock mounts include the clear plastic gaskets, too.
The method for the rears is the same as the front. Push the studs through the chassis and start the nuts, but don’t torque them until you have the bottom bolt threaded, too.
The passenger-side bolts are easy to get to. You’ll have to remove the full filler and evaporative hoses on the left side.
A floor jack and a wooden block are helpful to hold the control arm in the right location so you can thread the lower mounting bolt through the lower control arm and shock. This is a 17 mm bolt with a 70 foot-pound torque spec.
An impact wrench makes short work of the job on the bottom. Use a torque wrench for the final heave-ho.
There isn’t much room for an impact wrench up top. You need to use a swivel. The torque spec for the 14 mm nuts up top is 25 foot-pounds.
As mentioned above, it’s not necessary to remove the sway bar end links to do the rear shocks. The Penske shocks are much easier to work with than the Bilsteins they replace because the tolerances and dimensions are much more precise. They’re a lot easier to install as a result.
Image courtesy of Eric Green

2 COMMENTS

  1. I found that I am unable to adjust the ride height using the collar and sleeve. They both rotate with each other so no change is possible once they are in place. There needed to be a set screw or notch to hold the sleeve in place. Very bad design or am I missing something obvious?

  2. It depends on the spring perch/collar that you have. There are collars that have a bolt that squeezes the threaded sleeve and there are collars that use a pinch bolt that threads in perpendicular to the sleeve.

    If you send me an email to [email protected], I’ll send you a photo of each kind of collar.

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