DIY Spring/Shock/Coilover install

[MrTea]

Spring and Shock Installation Instructions
(shown on D2 Racing coilovers)

Tools Required:

Small and large socket wrenches
Deep 18mm Socket
12, 14, 15, and 18mm Sockets
Allen wrench (size TBD)
3" and 18" socket extensions
14mm, 17mm, and 19mm wrenches
Floor Jack
Jack Stands (2)

<>Brake Line Mount:
2 Hose Clamps (to fabricate a brake line mount)
Drill



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These are the D2 Racing coilovers to be installed. The were purchased from Mazda6tech's sponsor, CVR motorsports. They raise the spring rates from roughly 4kg/mm front, 3kg/mm rear to 13kg/mm front, 9kg/mm rear. The shocks are valved to make the appropriate changes as well, and suspension travel is cut roughly in half. The ride height is adjustable in the front, and all four shocks have adjustable rebound control.


Front Installation:

Step 1: Put car on jack stands; remove two front tires.


Step 2: Remove fork from lower A-arm. This requires a 15mm socket.


Step 3: Remove brake line from fork. This is a 12mm bolt.


Step 4: Remove sway bar from fork. This requires you remove a 14mm nut, but you may find the bolt rotating along with the nut. If you find it is not coming loose, use a 14mm wrench instead of a socket. You can then stick an allen wrench into the bolt to prevent it from moving with the nut.


Step 5: Repeat steps 2-4 on the other side. It's easier to do both sides at once, as you don't put tension on the anti-sway bar!

Step 6: Unscrew clamp from the bottom of the shock until the fork falls from it:


Step 7: Undo the 14mm bolts holding the top of the shock. Support the shock with your other hand, because it will fall once these are loose.


Step 8: Make the ride heights even to start. We'll provide good starting adjustment points once we take the measurements.


Step 9: Reinstall the new shocks. Repeat steps 7-2 in reverse order. Pay close attention to reconnecting the sway bar endlinks. They MUST be torqued to 45ft-lbs (or more), and this will probably necessitate you using an allen wrench to prevent the bolt from spinning along with the nut. The sway bar endlinks have a tendency to come undone when not properly torqued. You may wish to use blue Loc-Tite or a locknut just to be safe. Those using aftermarket sway bars should always use Loc-Tite and/or a locknut.

IMPORTANT: If you find that the sway bar is hard to reattatch, your left and right ride heights or not even. Sway bars are tensioned when the left and right ride heights are different, thus you will need to jack up one side of the car via the wheel or a suspension joint until the ride heights are even. You will also need to jack up each side of the car if you are installing the shocks one side at a time.

If you run into problems with sway bar tension, you can jack up a wheel (if it's on) or a suspension joint, both pictured below. If you find a lot of tension on any suspension part, this is probably the reason why! I did my installation one side at a time, which caused problems that would have been avoidable by doing both sides simultaneously.


Once the tension is relieved, this bolt holding the fork to the lower A-arm came out easily. I should have detached both sway endlinks before reinstalling the shocks to avoid having to do this!


Step 10: You may have noticed there is no place to put the brake line anymore. You'll need to fabricate a mount. Improvise any way you can.


I made this using a hose clamp. While not firm, it is plenty to keep the brake line from getting into trouble.


The improvised mount took just one hole through a hose clamp. A screw and nut go through this.


Another view- and we're done the fronts:


When you are done, you will notice the huge reduction of suspension travel. This is what we started with:


...And this is what we ended up with. The amount of droop is adjustable, so feel free to experiment. There is much debate on how much bump / rebound travel you want the shock to have. Pictured is between 2.5 and 3 inches, which seemed to work well. Remember it is far worse to reach the end of extension of your shock than it is to reach the end of compression. Bottoming out a shock can easily destroy it, and you want to keep sufficient shock travel for compression.


Step 11: Install the adjustment knob and adjust the shocks. Do not use the extreme end of the soft or hard sides, but find a compromise inbetween. I find between 3 and 4 turns (roughly in the middle) works best under nearly all driving conditions. Below two turns can get bouncy. You can rotate the adjustment knob a total of 6.5 times. It is a misconception that firming your shocks all the way give you better handling.

[MrTea]

someone post so i can put on the rear how-to (too many pics)

[djquik1]

posted....

Now where's the rest of the pics?

[MrTea]

Rear installation:

The rear takes a little more time than the front. Be prepared to spend a few hours. It's not difficult, but some bolts come out a little slow.

Step 1: Put the rear of your car on jack stands.

Step 2: Remove the rear suspension arm with the spring cup. This 15mm bolt comes out much easier if you support the spring cup with a jack, just to remove the tension.


Step 3: Disconnect the sway bar endlinks from the same suspension arm. You'll be removing a 14mm bolt.


Step 4: Push the spring cup down with your foot, and the spring will pull right out.


Step 5: Yank out those rubber progressive rubber bump stops. They pull right out. You can choose to either remove them completely or saw them in half. The D2 coilovers do not require them. I chose to remove to progressions of the bump stops. In hindsight, I wish I hade only removed one, but it doesn't matter. I never even reinstalled them, as they make your rear suspension progressive- something that is not desirable for a competitive car. If you plan on having lots of passengers in your car, you may wish to leave 3 stops. 2 is a compromise, as you shouldn't EVER hit the bumpstop in an empty car with only two progressions remaining. To reinstall the bumpstops, put a plank of scrap wood accross the spring cup. Put the rubber bumpstop on top. Then lift the spring cup with a floor jack, compressing it. You may need to use a screwdriver to help the bumpstop back into its home.


Step 6: You'll need to remove the brace that the top of the shock is attatched to. There are three 14mm bolts involved here. You'll need to look at them to figure out how to get at them. One is most easily accessible with an 18" socket extension (you can get by with less), and another is most easily accessible with a socket wrench with no extension. The last can only be gotten to with a 14mm wrench- and just barely. It takes a while to undo- hope it quickly becomes hand-tight.

This is the easy-to-get bolt:


The bolt I'm trying to get at here cannot be reached with socket extensions- but surprisingly, you can get it with the extensions removed.


The last bolt I couldn't get a good picture of, and you'll need a 14mm wrench.

Step 7: Disconnect the lower end of the shock. Admire the busted shock that is dripping oil. Remind yourself why aftermarket springs on stock shocks are a bad idea. This requires an 18mm socket.


Step 8: (not pictured) Disconnect the brake line mount. It is directly above (and and hidden by) the shock in the above picture. You'll need to disconnect this to make room for the shock to pull out.

Step 9: (not pictured). Pull the shock out. It's a tight fit, but you'll get it after a short while.

If you still have trouble after disconnecting the brake line, you can drop the subframe. You should not need to drop the subframe if you play around a little bit, but if you get frustrated, the subframe is an easy next step.

The subframe is supported by only two big bolts on each side and is rather easy to lower. You will need a deep 18mm socket to get them off.

Make sure you support the subframe before you start. You only want to loosen one side at a time and support middle, thus keeping the subframe in place until you're ready to lower it.


The first big 18mm deep socket bolt:


Other big bolt (Deep 18mm):


These are the other two "small" bolts you'll need to undo before the subframe drops (12mm).


Once you have the subframe loose, GRADUALLY lower the jack roughly 1/2 an inch. This should be MORE than enough to get the shock out! (As a friendly reminder, you need not lower the subframe at all to get the shock out- this is only a just-in-case tutorial!)

When you finally pull the shock out, you should be left with a mount looking like this. That tab on the end probably will have bent as you removed it. It serves no purpose. Yell at it for making life difficult, and break it off if you feel like removing stress. It makes the reinstallation easier.



Step 10: Replace the shock. Pay CLOSE attention to the angle the shock is to the mount! It's roughly 30 degrees off perpendicular. When you replace the shock, the new one MUST be torqued down at the same angle, or you'll cause unnecessary wear on the new shock and/or bushing. That said, remove and replace the shock. The bolt holding the shock will be on tight. You'll need a combination of 15 and 17mm wrenches and/or sockets. Torque to 70ft-lbs.

IMPORTANT: If you are installing a monotube shock such as the D2 Racing coilovers, you can probably mount it upside down. D2 has not yet confirmed this, but it should be true of all high-pressure monotubes. Mounting upside-down has two benefits: it will put the dampening adjustment on the bottom where it is more accessible, and it will reduce unsprung weight by keeping the heavier part of the shock on the chassis. Dual-tube shocks such as Koni Yellows will NOT work upside-down.

Make sure you have your rear shocks adjusted before you reassemble everything. I would recommend making the rear shocks just slightly firmer than the fronts to create a transitional bias away from understeer. Once you're done adjusting the shock, make sure the bolts on the end of the D2 shocks are on tight against the mount, or it WILL rattle! You'll need a 19mm wrench to tighten it. Also make sure to use blue loctite on the bolts for the rear shock assembly. It was on there stock, put em back on... talk about some major rattle to knock that crap loose!

Step 11: Reassemble! The 14mm bolts get 40 ft-lbs. The 15mm bolts get 50ft-lbs.

Step 12: (not pictured) It's finally time to put the spring in. Push the spring cup down with your foot and insert the spring, just as the other one came out. Make sure the coil is aligned in the cups. There is a plastic spring cup in the bottom and a rubber one up top.

Step 13: Recompress the spring. Use a jack.


Step 14: People say this bolt is a difficult to re-align. It's not. Use a screwdriver. Insert and pull up, hard. The parts should align and the bolt will go in. If it doesn't, jack the arm up higher. Keep trying and wiggling the bolt until it slides right in.


Put the wheels back on and you're done!

[shutterbug2020]

Excellent write up & nice pics too!

[MrTea]

Though i'd like to say thanks, i don't do write-ups...i copy them over to here. I don't mind tearing into things first, but i just don't have the patience to stop for pics along the way...then write a how to.

Unfortunately 6tech isn't around anymore, but hopefully we can save some of the great DIY's they brought us.

[threewhistles]

Thanks for the post. It's just in time.

[momo1978]

how do you take off the dumper fork from the shock.. because i have a 08 6i and i can't takeoff the dumper fork

[the mazda]

AWESOME DIY WRITE UP. THANKS BRO