General Description.


The general layout of the suspension design in the FD is known as double-wishbone.

But this is an over-simplification.


The front is pure double-wishbone. There is nothing particularly complicated about the front suspension.

There is a hub knuckle, which holds the whole hub assembly including the brakes. This is mounted by ball-joints** on an upper control arm and a lower control arm. There is a spring/shock unit on each side, mounted at the bottom to the lower control arm, and the chassis at the top. There is also a swaybar (or anti-roll bar) between the two sides, the ends also mounting to the lower control arm. The swaybar is mounted to the front cross-member by two saddles with rubber bushes. Both the upper and lower control arms are made from cast aluminium.

The upper control arm has no adjustments at all. It is fixed to the chassis by two bolts, through rubber bushes that are pressed into the control arm.

The lower control arm is also mounted via two big rubber bushes, but these have eccentric carriers, used for adjusting both camber and castor.

Toe is of course adjusted on the tie rod ends from the steering rack.

This is the lower front control arms.


This is the upper front control arms.


This is the whole front suspension system, including the cross-member, steering rack, engine mounts, hubs & brakes, control arms, swaybar springs/shocks... as it sits in the car.



The rear suspension is slightly more complicated.

It is still considered to be of double-wishbone design, but it is also described as a multi-link design.

There is a hub knuckle which holds the hub and brake assemblies. This is mounted by pillowball** bushes to an upper and lower control arm. There is a trailing arm connected to the outer end of the lower control arm, that runs forward to the chassis. There is a toe-control link, which mounts to the hub knuckle at one end, and the chassis at the other. There is a spring/shock unit on each side, mounted to the upper control arm ay the bottom, and the chassis at the top. There is also a swaybar connected to each side. This swaybar is mounted to the chassis by simple saddles and rubber bushes. The upper control arms, lower control arms and trailing arms are all made of cast aluminium.

The upper control arm has no adjustments at all. It is mounted to the chassis by two big rubber bushes that are pressed into the control arm.

The lower control arm is mounted to the body by a single bush that has an eccentric carrier. This is used for camber adjustment.

The trailing arm is mounted to the chassis at it's forward end by a single rubber bush. It bolts to the lower control arm through a pillowball bush. There is no castor adjustment built into this from factory.

The toe-control link mounts at both ends via pillowball bushes pressed into the link. The toe link is fully adjustable, and is used for aligning the toe of the rear wheels.

This shows the rear components. Left to right: Toe link. Trailing arm. Lower control arm. Upper control arm.


This is the whole rear suspension system including control arms, trailing arms, toe links, swaybar, sub frame, differential, drive shafts, hubs & brakes, springs & shocks... as it sits in the car. (thanks to Forcefeed for the pic)




**Pillowball bushes are a metal-on-metal design, much like a rose joint. They offer limited movement around their axis, and no lateral movement just like a rose joint, but are of a design much like a normal rubber bush. They are however NOT all the same. There are 10 in total in the rear of the FD with 3 different part numbers between them.

Here are some examples.





**EDIT: Since writing this, I have discovered that the normal ball joints on the ends of the front upper and lower control arms are not replacable. I don't know how true this is, but Mazda can't sell you a ball joint. You have to buy the whole control arm (expensive)... I don't know if it would be possible to press these ball joints out of the control arms or not. The only way to know would be to try, and that could destroy a control arm.

So if anyone has a front control arm that is 100% stuffed, or possibly even broken, please let me know as I would like to try and remove a ball joint from it...

**EDIT: Apon inspecting the full spare set of control arms I have today, I discovered ther Rear Lower Control Arm inner bushes are in fact another pillowball bush. They are a lot bigger than the rest of the pillowballs, and they are also made of different materials. The casing seems to be made of some sort of fibre reinforced plastic. Fulcrum don't make a replacement for these in urethane. But they definitely seem to be a pillowball. You can move the centre around like a pillowball, which is mostly impossible to do with a 'normal' rubber bush. Maybe this is why Fulcrum don't make a replacement.

I haven't heard or read much about these bushes failing. Maybe their physical size is enough to prevent this.

Potential Problems:


The main problems encountered are wear and tear.

The biggest is wear in the pillowball bushes. Being metal-to-metal all the time, they will suffer from hard use, or age. If the rubber seal around them deteriorates, then dirt can get in there too, which wears them out faster.

This is likely to result in a clunking sound coming from the back of the car. You will hear it happen going over small bumps in driveways more than big bumps on the road.

The only way to check them properly is with the car off the ground with the wheels off. You need a big lever, and you have to put strain on the bushes to check for movement. ANY lateral movement is bad.


But being as they ARE a metal type bush, you should expect to get more road noise than you may be used to from other cars. Unfortunately, this is unavoidable.

Unfortunately, you have very few options when the pillowballs need replacing.

Mazda Australia charge about $120+ each, regardless of which one it is.

Some aftermarket companies offer them in Japan. They even make replacements for bushes that are normally rubber. But unless you have yourself a dedicated track car, this would not be such a good idea.

But if a pillowball dies, there is not much for it but to go to Mazda, unless you can get them from Japan. Mazda Japan usually has very good pricing. If you know someone over there, often it will work out cheaper to pay them to buy them retail from their local Mazda dealer, and send them to you.


There is however a recent option for the replacement of most of the bushes, including pillowballs in the rear toe link.

Fulcrum suspension now offer an almost complete set of suspension bushes in Urethane. This includes replacements for the toe link. It does NOT replace any of the other pillowballs however.

The only other bushes they don't offer is a replacement for is the inner bush of the rear lower control arm (which is also a big pillowball bush) and both swaybar D-bushes. I have personally asked them why they don't offer the control arm bush, and didn't get a straight answer, other than because it is a pillowball bush. No one in their right mind would want Urethane in the swaybar mounts, it squeaks badly.



The only other real problems will come from old age of the rubber bushes. But these can be bought new from Mazda, in various hardnesses, as different spec cars had softer or harder bushes. You would need the specific part numbers though.

And of course there is now the Urethane option. Fulcrum offer the following:

Front:

Upper Control Arm, Inner bush. Part number SPF2821K
Lower Control Arm, Inner Front bush. Part number SPF2822K
Lower Control Arm, Inner Rear bush. Part number SPF2823K
Steering Rack mounting bush. Part number SPF2370K
Swaybar mounting D-bush. Part number SPF2819K
Upper Control Arm, Inner bush.* Part number SPF2821XK * Eccentric for extra camber adjustment.
Lower Control Arm, Inner Front bush.* Part Number SPF2822XK * Eccentric for extra camber adjustment.
Lower Control Arm, Inner Rear bush. Part number SPF2823XK * Eccentric for extra camber adjustment.

Rear:

Trailing Arm to Cross Member bush. Part number SPF2677K
Toe Control Arm - Outer bush. Part number SPF2676K
Toe Control Arm - Inner bush. Part number SPF2675K
Shock Absorber Lower bush. Part number SPF2680K
Control Arm Upper - Inner bush. Part number SPF2678K
Control Arm Upper - Inner bush.* Part number SPF2679K * Eccentric for extra camber adjustment.
Swaybar mounting D-bush. Part number SPF2535K

These can all be bought as separate kits, or as a whole in one big kit. You can choose to have the eccentric bushes or the normal bushes for the rear upper control arms.

SuperPro Enhancement Kit. (normal) Part number KIT130K
SuperPro Alignment Kit. (eccentric) Part number KIT130ADJK



There is one other bush that Fulcrum make, but it isn't really part of the suspension.

This is the Diff Cradle bush. Part number SPF2674K

Now, I haven't mentioned this yet in the suspension info, because they aren't REALLY part of the suspension system. They are a part of the driveline.

BUT, they do deserve mention here, as these are another possible cause of clunking noises from the rear of the car. Actually, they are probably the most common cause of clunking noises from the back of the car.

These Diff Cradle bushes are a big liquid-filled rubber bush. They are also a pair of only 4 points that holds the entire powertrain of the car to the chassis.

With hard use, or simply age, these bushes loses their tension, and even get to the point of leaking. When this happens, you will get more clunking noises in the rear. But this will also extend to when you select a gear while stopped, or during hard gear shifting.



Other than that, there are normal things to worry about like ball joints in the front and swaybars.... wheel bearings, normal car stuff.

The tops of the shocks are also a big rubber bush, but they are not likely to have much in the way of problems.

Of course you could always break or bend a control arm too, but you would have to hit some serious obstacle to do so. I have personally gone over a median strip at decent speed, getting completely airborne and coming down hard. Nothing serious broke, and nothing bent. All that did happen was the eccentric adjustments all pushed out, and I needed a wheel alighnment. One of the front swaybar mounts was found to have a crack in it, but it is possible that was there before.


But overall, the suspension layout is a good design. It was a definite stand-out in the early 90, and is still considered fairly modern 16 years later. It is a very good handling car.

There is also a lot of adjustment possible from the factory. Some models even came with height adjustment as standard. But being all adjustable as it is requires proper alignments to be done on a regular basis. The only thing missing would be rear castor adjustment, for the hard-core racers. And you can buy aftermarket trailing arms to take care of that.



**EDIT: Since writing this, I have discovered that the normal ball joints on the ends of the front upper and lower control arms are not replacable. I don't know how true this is, but Mazda can't sell you a ball joint. You have to buy the whole control arm (expensive)... I don't know if it would be possible to press these ball joints out of the control arms or not. The only way to know would be to try, and that could destroy a control arm.

Torque Settings:

Here are the factory recommended torque settings for all of the main mounting bolts in the suspension of the FD.


NOTE: All of the following information and pics were lifted from this site... http://13b.power.ne.jp/main_contents/type5_parts_list/
Even though this site is a tech resourse for cars made from 1999 onwards (Type 5 & 6), I have personally cross-referenced the following settings with my own workshop manual for cars made until 1995, and all of the settings match.



Front:


16-23 Nm
_______________________________________________________



A= 59-73 Nm
B= 37-53 Nm
C= 94-116 Nm
D= 16-22 Nm
_______________________________________________________



A= 94-116 Nm
B=94-116 Nm
C=79-107 Nm
D= 59-73 Nm
E= 94-116 Nm
_______________________________________________________



A= 18-26 Nm
B= 37-53 Nm
_______________________________________________________



A= 47-62 Nm
B= 32-46 Nm
C= 9.9-13 Nm
D= 0.4-0.58 NM
NOTE: Not all cars have C & D in this picture.
_______________________________________________________


Rear:


A= 46-62 Nm
B= 32-46 Nm
C= 94-110 Nm
_______________________________________________________



A= 16-23 Nm
_______________________________________________________



A= 94-110 Nm
B= 59-73 Nm
C= 59-73 Nm
_______________________________________________________



A= 94-116 Nm
B= 94-116 Nm
C= 59-73 Nm
D= 59-73 Nm
_______________________________________________________



A= 59-73 Nm
B= 19-25 Nm
C= 64-78 Nm
_______________________________________________________



A= 54-76 Nm
B= 18-26 Nm
C= 94-110 Nm
_______________________________________________________

Here is a step-by-step guide to replacing your springs and shocks with 'coilovers'.

The original equipment is a coilover design anyway, so all you are really doing is replacing the old units with new ones.


The process will be pretty much the same, no matter what brand of replacements you have. I used Tein Super Street coilovers, from the Australian disributor Fulcrum Suspension. These are ADR comliant, and come with a full warranty.





It is a good idea to go over the new stuff, while going through the fitting instructions, just to be familiar with what you have. It is also a good idea to make sure the settings actually match what the instructions say, which mine did. 8)



I have limited space and tools, so I did one end at a time, starting with the easy end, the rear.


First thing to do is jack the back end of the car up high enough to allow enough room to work under there. ALWAYS USE STANDS. NEVER RELY ON A JACK TO HOLD THE CAR UP. I used stands, AND left the jack in place.



Open the rear hatch, and remove the rear wheels.

This is what the suspension looks like with the wheels off.



Next, remove the covers off the strut tops (1), and undo the bolts on both sides of the strut brace (2), and remove the center bar.




Now you should get under the car, and undo the bolts that hold the swaybar to the body on both sides, so the swaybar hangs down (3). This is so you can remove the lower shock bolt later.



Now undo the 3 bolts that hold the top of the shock in, as well as the mounts for the strut brace (4). It is a good idea to leave the center bolt in place (5), so the shock doesn't fall out and damage anything, including you.



Now you need to undo the lower shock mount. You will need an open ended spanner and a socket on a good breaker bar. From memory they are 17mm.



Once that is undone, you can pull the bolt out, but it will still be attached to the swaybar.



Now get back into the boot, and undo that center nut at the top of the shock (5). Hold the shock, so it doesn't fall on your foot. :x



Now you should be able to pull the shock out. You may need to wiggle the bottom a bit to get it off the control arm.

Here is a comparison between the Teins and the stock crap. Note the difference in actual length.



Put the new shock in, and hold it up into the strut top, while you put the mount for the strut brace on, and do the 3 nuts up by hand. Note, you don't need the nut from the center of the original shock, or the silly bush.



Now you put the lower end of the shock in place, and put the bolt in. You then do it up nice and tight with that breaker bar and spanner.



Now get back inside, and tighten the 3 top bolts up nice and tight. I didn't use the breaker bar for these. A normal ratchet will do it. While you're there, put the bar of the strut brace back in, and tighten up the bolts for this. Again, a normal ratchet is enough.

Finally, you need to get back under the car, and bolt the swaybar back up to the body. Note the difference in the angle of the swaybar compared to the original shocks. This is due to the new shocks being a heap shorter overall.



Before you put the wheels back on, it is a good idea to go round and make sure everything is nice and tight. Also check the lower spring seat on the new shock if they are adjustable, and use the 'C spanners' to nip them up as well.

Put the wheels back on, and put the car back on the ground. Put the trims back on the strut tops inside the car, and close the hatch. The rear end is finished.


The fronts are a touch more involved.

First off, jack the front up and put it on stands. Open the bonnet, and remove the front wheels.



Now you need to remove the front strut brace. Undo the two bolts on the center bar first (7). Then undo the three bolts around the top of the strut (8.), but leave the center one there so it doesn't all fall out later on.



Now get under the car, and unbolt the swaybar from the mounts on the body (9)...(note, your mounts will probably not be blue... mmmm RE Amemiya goodness... 8) )



Let it hang down.



Now remove the clip that holds the brake line to the strut with a pair of pliers.



Now unbolt the ABS sensor (10).



Carefully pull the sensor out of the hub and let ot dangle.



Now undo the lower shock bolt (11), and knock it out. 17mm again from memory.



Now comes the really fun bit. You need to undo the upper control arm, and remove it from the body (12). These are 14mm on both ends, and they ARE TIGHT. They are also probably slightly rusty, so a little WD40 or similar is a good idea. You will round the nuts if you don't. Use a big breaker bar, and a spanner.



The control arm should come out easy enough.



Now you will need to get to the bottom of the shock with a hammer, and knock it out of the control arm. Once that is free or very close to it, you need to go back to the engine bay, and remove the center nut on each strut (8.). Hold the shock body while you do this as once this comes off, the whole lot will want to fall out. The lower control arm will also drop now. The whole hub, with the disc and caliper will drop too. This weighs a bit, so be careful.

But now you will be able to work the shock out, then pull it out the top of the control arm.

It looks like this with no shock in it.



Here is the Tein next to the stocker.



Now get the new shock in there, and hold it up in the tower and put the three nuts on the top by hand to hold it there. They don't need to be tight yet, just hand tight will do, so it doesn't fall out. It's good if you can get the mount for the strut brace on at the same time to save doing it again later. BE SURE YOU PUT THE CORRECT ONE IN EACH SIDE, AS FRONT SHOCKS ARE DESIGNED AS A LEFT AND RIGHT.

Put the lower shock bolt in without the nut, just to hold the whole lot in place (13). You will also need to position the upper control arm back into place and put the bolts in at the same time (14). Maybe try doing the upper arm first.



Once it's all sitting in there where it needs to be, you can go and do everything up. The two bolts in the upper control arm, and the lower shock bolt all want to be TIGHT, using the breaker bar.

Now get up the top, and tighten up the top 3 bolts (8.). Note you don't need the center bolt, same as the rear. Also put the bar back in the strut brace (7) and tighten it up. A normal ratchet is good enough for this.



Now get back under the car, and clip the brake line into the holder on the shock body (16). Also carefully put the ABS sensor back in the hub and do up the bolts that hold it and it's harness (17).



Now bolt the swaybar back up to the brackets under the car (19) .



Now go round and make sure everything is tight. Also check the lower spring seat if it adjustable, and use the 'C spanners' to nip those up as well. Put the wheels back on, and put the car back on the ground.

Once it's on the ground, go round and tighten up all the wheel nuts. It also can't hurt to check all the strut top nuts once it is back on the ground.

And that is pretty much it. I reckon I could do that again in about 3 hours total, now that I have done it once. No power tools or air tools are required. Just sockets, spanners, a breaker bar, a jack, some stands and a pair of pliers.

All you need to do now is get a wheel alignment, and get the shocks adjusted to a desirable setting. I left all of the settings on the shocks as recommended from the factory and they work well. But that will depend on the shocks you get, you, your driving style, and what you want to do with the car.


Here is a few pics of the car after said Teins were fitted, with the factory settings as supplied by Fulcrum.






Enjoy. 8)

For track work

Front
Camber- Max (prob get around -2.5)
Castor- Max
Toe- 0

Rear
Camber- Max (prob get around -3)
Toe- Total of 4mm toe in

For street back your camber off to say -1.5

I will edit this later for ride height recommendations

Brad

Ok, you to measure height accurately measure from the bottom of your rim, up through the centre of the wheel to the lip of the guard. This measurement obviously varies with different size wheels but is more accurate than guessing the centre of the wheel.

To accurately compare to these given heights you want to measure the car on level ground, with half a tank of fuel and no passengers/other than normal weight in the car. If you have bigger wheels than 18's chances are you want your car slammed and the below recommendations don't apply

18's

Front 595mm
Rear 605mm

17's

Front 580mm
Rear 590mm

16's

Front 570mm
Rear 580mm

These are all a good place to start. It will give a ride height similar to this on 18's



Loaded on 17's



It will give you enough ground clearance and suspension travel that you wont scrub tyres on anything but the hardest loading.

Brad

thanks for all your help ive got a lot of reading to do

What are the consequences of not properly applying the correct TORQUE settings that have been advised. For people who do not have a torque wrench. Is it really necessary?

Cheers

See the post above where I changed my springs/shocks to Teins...


... I don't own a torque wrench.


I just made sure that if it was really tight, I did it up the same.


But you can use the info of the torque settings to help you out.

Say it is meant to be 94-116Nm, then I would use a decent length breaker bar, and lean on it heavily to tighten the bolt up.

If it only needs 18-26Nm, then a small ratchet and socket will do the job nicely.


But in general, with most/all of the suspension in the FD, there will be no concequence if you over-tighten anything. It just makes it harder to remove again later.

Just one suggestion, its a good idea to tighten up the strut top bolts once the vehicle is back on the ground after giving it a quick bounce. Sometimes if the strut top isn't properly seated you can snap the studs when you tighten up the nuts.

Great write up BT, very helpful and you make it look so easy

OK... so I have an update after doing a set if Tein Super Street's into ol-skool's car...

Andy went and bought a set of Jap Spec Super Street's... No big deal really because they run the same spring rates as the Aus spec versions...



BUT... and it's a BIG BUT...

When buying Jap spec, unless you specify you want top mounts, you don't get them (they will cost extra). You need to reuse the factory top mounts. This is not as straight forward as you may think.

You need to cut the old rubber dirt guard from the top mount, pull the old bump stop out, then file the D shaped hole in the top bush out so it fit's over the aftermarket round centre bar. If you read Japanese this would be easy enough to work out. It took a little while but I twigged to it eventually. (We even twigged to the fact that they supply you with a tiny file to fix the top bush, but it would take you a week to do the job with it)

The other slight annoyance was the spring seat of the Aus spec comes set to the recommended 100m ride height settings. The Jap spec units don't.

Not really Earth shattering stuff, we did it all in my garage. But it requires a little work. For starters, you DEFINATELY need a set of spring compressors so you can get the factory top mounts off the old units without killing yourself. You also don't know where to set the spring seats unless you happen to be able to read Japanese.


It also means that your stock units are now totally worthless, and you may as well through them in the bin (which we did).

So instead of the whole job taking 2-3 hours of lazy work, it took a lot longer.


In short, you may be able to get a set of Jap Spec Super Streets a few hundred dollars cheaper than you can get the Aus spec from Fulcrum, but in short it would be better all round to just bite the bullet and spend a little extra to start with.

It makes the install a lot quicker and easier, and you can keep your stock units whole so they can be sold or kept as spares.

thank you thank you thank you

I'm about to replace a tonne of bushes , this thread is gold. Thanks again!!!!