“OE rubber bushings and mounts are notorious for degrading and ultimately failing over time because they are often bonded to the inner and outer sleeves that encase them,” Martin tells us. “This causes a constant torsional strain on the bushings whenever the suspension components move.”
For that reason — along with cost — we decided against replacing the suspension with the same original equipment. Martin affirms, “Replacing the bushings as opposed to the entire component will save car owners hundreds, if not thousands, of dollars while completely restoring and upgrading that suspension component’s performance.”
When asked why he thinks this upgrade is a smart move on our part, he says, “In a track situation, you’ll lose time in the corners and can’t get back on the power quickly. The suspension components misalign and create sloppy handling, wheel hop, and other second-sucking problems. Our Hyper-Flex Performance Polyurethane bushings are designed to be ‘free-floating,’ allowing the suspension component to move freely, without the resistance of a bonded bushing. They are resistant to oil, grease, and other road contaminants. They will not degrade or fail over time. You will see an instant improvement in steering response, handling, and control.”
The Teardown Overview
Hands down, the toughest part of upgrading to poly bushings is getting the old rubber bushings out. For the most part, you are disassembling the entire suspension, so it is imperative to take a lot of “before” pictures and be methodical about your process. We had four guys working on the car — none of which had ever done an entire car before — and it took the better amount of the day. Once we figured out a method, it got easier. In the end, we were all dirty (some bloody) and tired.
This installation was done in a home garage, with no access to a lift or even a press, so this was about as grassroots as you can get. We started by jacking the car up and getting four jackstands securely under the body (Miatas are uni-body). Once in the air, we removed the wheels and got to work on removing the suspension. We took care of the front end first, then tackled the rear.
As you can see, we’re bare bones in this garage — no lift, no press, only hand tools, and muscle!
Front Control Arm Removal
First, we disconnected the adjustable links connecting the
Eibach sway bar to the control arms. The next step was to take out the cotter pin holding the castle nut in place on the tie-rod and loosen the castle nut a few threads. To pop the tie-rod end out of its seat in the spindle, the Miata has a flat spot on the spindle you can hit with a mini-sledgehammer to jolt them free. Once loose, you can remove the castle nut and swing the tie rods out of the way.
Next, we removed the brake-caliper-mounting bolts and set the caliper and rotor on a bucket, out of the way. The next step is to remove the spindle. As with the tie rods, we removed the cotter pins and backed off the castle nuts for the upper and lower ball joints. We used a pickle fork to separate the ball joints from the spindle. Once free, we just needed to remove the castle nuts and set the spindle off to the side.
The sway bar, tie rod, caliper, rotor, and spindle all have to come off to get to the control arms. We left as much as attached as we could including the sway bar, tie rod, coilover, and caliper. There are three bolts holding the control arms on, one for the top and two on the bottom.
Now, we could remove the
Pedders coilover, first by removing the lower mounting bolt, then the two upper bolts. I needed one of the guys to push down on the lower control arm to get the coilover out. At this point, all that is left to remove is the control arms themselves.
Before loosening anything, heed my advice. The lower control-arm bolts have a flat on one side with a cammed washer that adjusts the camber/caster/toe. It is a great idea to mark where your alignment washers are pointing with a Sharpie or chalk pen on the control arm so you can get the alignment close to where it was when you put it back together. This is where my inexperience (and maybe too much exuberance) came into play.
I took a few pictures, thinking I’d be able to refer back to them. However, unless you mark the washer location on each arm for the photo (LF, LR, RR, RF), it’s almost impossible to tell which washer you were photographing. It isn’t a major deal as you’ll have to realign the car anyway, but it’s nice to get it close, especially if you plan to drive to the alignment shop. Oh well, CrossTime was going on a trailer, and I was going to cross-weigh and realign it later.