CarCare101: Project Miata: Suspension Tear Down

[Bruce Nunnally]

It’s time to start our first major overhaul on Project Miata. The car’s 20 year old worn out suspension complete with blown shocks and crumbling  bushing necessitated we start there. So we’re going to tear everything down and completely rebuild the entire suspension.

Step 1 – Let It Marinade:

Before we can get started with tearing down Project Miata’s suspension we’ve got to tackle 20+ years for rust and neglect. Since your suspension spends a lot of its time exposed to the elements you can pretty much expect every single nut and bolt to be seized tight with corrosion.

The best tool we’ve found for dealing with corrosion is good old Liquid Wrench. So go ahead and give everything a good soaking of Magic in a Can, then order a pizza and turn on your favorite game. This stuff needs to soak for a few hours.

Step 2 – Those Pesky Tie Rod Ends:

No matter how much you whack them with a hammer or beat them with a pickle fork they just won’t turn loose. Happily there’€™s a fix for that! But first remove the cotter pin and castle nut.

Step 3 – Ball Joint Separator:

This nifty little tool is only $10 or $15 at Harbor Freight. Simply slide the split jaws between the ball joint and place the hook on top of the threaded taper. Then crank down on the tool’s threaded rod. As the tool applies pressure to the ball joint it will pop loose and with a bit of luck it won’t even damage the rubber boot. In our case we aren’t reusing any suspension bits so these are getting trashed anyway.

**Note: Don’t forget to lube the threaded rod on the Ball Joint Separator or you may strip the threads.

You can get the tool here: http://www.harborfreight.com/3-4-quarter-inch-forged-ball-point-joint-separator-99849.html

Step 4 – Pulling Cotter Pins and Conquering Castles: 

Now that the tire rod end is loose from the front hub we’€™ve got plenty of room to work. Go ahead and remove the cotter pin and castle nut from both the upper and lower ball joint.

Step 5 – Popping the Upper and Lower Ball Joints:

Time to make use of that nifty ball joint separator again. We need to pop both the upper and lower ball joints. These ball joints will have more tension in them than the tie rod end did, so keep and eye out for flying bits when they finally do pop. They also make a quite satisfying KUPUNG! noise when they cut loose that’s loud enough to frighten the wee out of small children.

Step 6 – Set the Hub Aside:

Provided the hub didn’€™t go flying across the room when you popped the last ball joint.  Go ahead and set it aside as we will be reusing it since the wheel bearings are still good. (And before you say anything I know the brakes are just hanging loose on the old rubber brake lines. And yes I am aware that this is not the correct way to do things. They *SHOULD* be tied up. However these brakes and brake lines will not be used on this car. As discussed earlier we’€™ll be putting on the brakes from the crispy car, with new braided stainless steel lines.)

Step 7 – Removing the Sway Bar End Links:

The sway bar end links have defiantly seen better days. It’s probably a good idea to let these have a good long soak in Liquid Wrench before trying to break the bolts loose.

Step 8 – A Broken Bolt:

Of course you could just grab a bigger breaker bar like we did. Which as you have probably already figured out led to the inevitable… we twisted the bolt in half.

Step 9 - Disconnecting the Sway Bar:

Since the lower bolt broke, we’ll leave the end link connected to the lower control arm for the time being and disconnect the sway bar with the upper end link bolt.

Step 10 – Unbolting the Lower Ball Joint and Shock Mount:

Only Three bolts left before the lower control arm will swing free on the alignment bolts. Start by pulling the long bolt on the lower ball joint. In our case we found after we removed the nut, that the shaft of the bolt was seized tight to the lower ball joint it’€™s self. It took some gentle persuasion with a breaker bar and a whole lot of Liquid Wrench to get it to break free. Once you have the bolt turning. Put your impact gun on the bolt and spin it for about 2 minutes. This will break loose all the corrosion and you should be able to safely drive it out with a hammer without mushrooming the threads of the bolt.

Once that’€™s done unbolt the shock which will give you access to the short bolt holding the tail of the lower ball joint to the control arm.

Step 11 – Removing the Upper Control Arm:

Removing the upper control arm is quite simple just removing the long bolt holding it in place. (As a side note is you are replacing your shocks and springs all you need to do is remove this bolt. The entire front suspension will swing away and you can pull out the shock assembly. This is what is referred to as the €œ”long bolt method”.€)

Step 12 – Dropping the Shock Assembly:

Only two 12mm flanged nuts hold the shock top hat in place. Well, err in our case only one is still attached. It appears as if someone went all gorilla on one of them and broke it. Regardless undo the flange nuts and the entire shock assembly will drop out.

Step 13 – Rear Alignment Bolt:

This bolt is tucked up tight to the bottom of the fire wall / wheel well area so it’s a pain to break the nut loose with a socket, but a wrench may round the head off. Be prepared to cuss an engineer on this one.

Step 14 – Front Alignment Bolt:

This should be the last bolt holding the lower control arm in place so be prepared to catch it when it falls.

Step 15 – That Damned Sway Bar End Link:

And no amount of liquid wrench, or persuasion with the impact gun will budget it. This calls for drastic measures…

Step 16 – Let There Be Sparks:

Ah I love the smell of air tools in the morning! …Or late at night as the case may be… Since we’re not going to use the stock swaybar end links there’s no reason to fight that broken bolt. We ended up having to cut both of the end links loose.

Step 17 – These Boots Ain’t Made for Walking:

Grab your trusty pliers and remove the clamps holding the dust boot on the inner tie rod. Then just slip the boot right off the shaft… yeah right. Nothing’s that easy on a 20 year old hunk of junk like Project Miata. Get ready to pull like crazy and bust your knuckles when that boot finally pops loose.

Step 18 – Removing the Inner Tire Rod:

There’s a washer hold this thing in place. The ears of said washer are bent down over the flat spots on the ball join. Take a long screw driver and a hammer and go to town on those bad boys. Once you’ve driven all 4 ears back just unscrew the inner tie rod using a large adjustable wrench on the now exposed flat spots… and then call your local Mazda dealer to order a set of $9.00 (each) washers to replace the ones you just mangled.

Step 19 – Remove the Rear Brakes:

It’s a fairly simple process. See those two big holes? Pull the bolts that go in them. The caliper will lift right off the rotor. Use zip ties to hold it out of the way. Don’t just let it hang like we did. The rotor will probably be rusted tight. Check out our break removal write up to see the various methods we used to remove it.

Step 20 – Removing the Rear End Links:

A breaker bar will become your new favorite tool. Use it and a wrench pinned agianst the spring to break the bolt loose. If you are replacing the while sway bar and end link like we are then don’t bother with the upper nut and bolt.

Step 21 – The Rear Sway Bar Mounts Are Shot:

This is a great shot of why we are replacing all the bushings on Project Miata. This one has deterriorated so much that it’s no longer in contact with the bar… just look at the gap! Not to mention how bad its crumbling.

After removing the bolts holding in both mounts the rear sway bar should come free. Toss it on the scrap pile.

Step 22 – Removing Lower Upright Bolt:

The lower upright bolt is most likely rusted in place. And impact gun will be your best bet to get it loose. What we found works best is the break the nut loose with your trusty breaker bar. Then grab a 2 or 3 foot long cheater pipe (a thick walled peice of tube or pipe you can slide over the end of your breaker bar for more leverage) and move your breaker bar to the head of the bolt. Using the cheater pipe / breaker bar combo get you and a fat friend to pull on the pipe and eventually the bolt will begin to spin.

At this point grab the air gun. Continue to use the air gun to spin the bolt for about 15 minutes alternating directions. This will polish off the majority of the rust hold it in palce.

Now is when you will discover that the bolt is inevidably bent. Place a block of wood over the threaded end of the bolt and use a bfh to gently whack the hell out of it until the bolt comes free.

This will be a pain in the *smurf*. You will more than likely need to replace the bolt as it is probably bent. You will kick the cat, cuss the dog and be in general quite irritable after comming in contact with this bolt. You have been warned.

Step 23 – That Cursed Nut:

So dumb *smurf*… er… I mean engineer at Mazda decided to use a caputured nut on the other end of the bolt used to attach the shock to the lower control arm. If you are lucky that nut wont break loose from it’s rusted tack welds when you crank on the bolt with your breaker bar.

After cursing the aforementioned engineer’s maternal lineage for several hours as we tried every way under the sun to get a wrench on that cursed nut. We finally hit upon the idea of just drilling a hole on the oppsite side of the control arm and using a socket on a long extention and a second break bar to hold the nut in place while we cranked on the bolt.

This works like a champ and is much much better that hacking up the bottom of your control arm to get a wrench on there. (This was the most common suggeston we found across the miata forums and definatly not something we’d reccomend.)

Step 24 – Upper Upright Bolt:

(Be you can’t say that ten times fast.) This one is easy. Grab your sockets and go to town.

Step 25 -Free at Last!:

Well almost. First we have to dive in to the trunk. But before we do that notice that we’ve left the bolt connecting the lower control arm and the shock in place for the moment. This will help keep everything steady while you take the upright bolts out. You can remove it after the top hat nuts are take care of.

Step 26 – Getting Access to the Rear Top Hats:

First open the trunk, it will make this part decidedly easier. On the driver’s side you will see a black panel. Unbolt the 4 10mm bolts.  On the passanger side you’ll need to remove the spare tire. (And yes those are shotgun shells in my trunk. What did you expect I do live in Texas afterall )

Step 27 – Into the Dark Cavern:

On both the passanger’s and driver’s side of the trunk there is a tunnel. In these tiny dark and cramped tunnels you’ll find the top hat’s of the shocks poking through. The passanger side is easy. the driver’s side however is burried up behind the fuel filler lines.

Step 28 – Removing the Lower Control Arm:

All that’s left to remove the lower control arm is unbolting the alignment bolts. A smart man will use a screw driver to score an alignment mark on each bolt’s face so you can get things close to realigned when it get’s reassembled. I however am not a smart man…

Step 29 – Removing the Upper Control Arm:

These are the last two bolts we have to remove. But there is a trick that will make it easier to do.

Step 30 – Accessing the Rear Upper Control Arm Bolts:

Mazda has kindly cut access holes on each side of the upper control arm. All you need is a a long extention and a couple of breaker bars.

Step 31 – What’s Left Hanging in the Rear:

The hard part is over with. We’re leaving the rear hub’s and brakes hanging. And since we are replacing the calipers and brake lines so there’s no need for us to tie them up properly.

Step 32 – Somebody Forgot the Front Sway Bar:

That’s it folks. We’re done. Time to pop the top on and cold one and inspect our handy work… and realise that some dumb *smurf* forgot to unbolt the front sway bar… /sigh

Next up we start the restoration process. We’re going to clean up and repaint the parts we are going to use and replace everything else.

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