How-To: Coilover Suspension Installation

[Tork Monster]

INSTALLATION OF KW VARIANT II COIL-OVER SUSPENSION ON A 300C SRT8

This procedure will also work on Chargers and Magnums. Although this procedure was written for KW Var II coilovers, it could be used for installation of other coilover setups as well as lowering springs, although some details may differ.

PROJECT DIFFICULTY: moderate-high

FRUSTRATION LEVEL: moderately high

TIME REQUIRED: 5-8 hours DOE

TOOLS REQUIRED:

• Hydraulic floor jack
• Wheel chocks
• Jack stands
• Coil spring compressors (2-types: dual external, front & single hinged-style, rear)
• Tape measure
• 1/2" drive metric socket set (16mm, 18mm...)
• 1/2" drive breaker bar
• 1/2" drive torque wrench
• 3/8" drive metric socket set (8mm, 10mm, 13mm...)
• 16mm, 18mm offset box wrenches
• Plenty of Heineken.
• Metric allen wrench set
• 6-foot prybar (just go buy one... you will use it for a lot of things!)
• 12-gauge wire
• 2-foot crowbar
• Pickle fork (ball joint separator)
• And more Heineken.

~~~~~~~~WARNING!~~~~~~~~

THE FOLLOWING DESCRIPTION IS NOT AN APPROVED GUIDELINE NOR INSTRUCTIONS ON HOW TO INSTALL SUSPENSION COMPONENTS. SERVICING SUSPENSION AND THE USE OF SPRING COMPRESSORS IS DANGEROUS AND COULD RESULT IN SERIOUS INJURY. INCORRECT INSTALLATION OF SUSPENSION COMPONENTS COULD RESULT IN SUSPENSION FAILURE AND LOSS OF VEHICLE CONTROL. IT IS RECOMMENDED THAT SUSPENSION WORK BE DONE BY EXPERIENCED PROFESSIONALS. THE FOLLOWING IS SIMPLY A DESCRIPTION OF HOW ONE PERSON INSTALLED THE KW VAR II COIL-OVER SUSPENSION ON HIS PERSONAL CAR AS A WAY OF RECORDING THE METHOD FOR FUTURE PERSONAL REFERENCE. THIS MAY ALSO BE VIEWED AS AN ILLUSTRATED METHOD OF DISCOURAGING THOSE FROM ATTEMPTING THIS WORK THEMSELVES. THE TEXT IS WRITTEN IN “INSTRUCTIVE” FORMAT FOR BETTER VISUALIZATION.

(1)- PREPARATION
Whenever jacking a car for any reason, the car should be parked on a level concrete pad. Working on a slope or on unstable surface can result in damage to the vehicle and/or injury.

Measure the distance to the fender for all four corners. Record this to use as a reference later.



Install wheel chocks on the wheels opposite from the wheel you are working.

The owners manual says nothing about how to jack the car, although placing the jack in the wrong place can damage the vehicle.

There is a rubber mount under the sills by rear door on each side for the rear jacking points. The fronts are located further towards the center of the car. See illustration:




Raise the front on one side of the vehicle. Install a jack stand adjacent to the floor jack to distribute the load and improve stability. Remove the front wheel. Place the removed wheel under the car just behind the jack stand, as an extra safety measure in case the vehicle shifts while raised.

(2)-FRONT SUSPENSION - SPRING COMPRESSION:
Install a set of dual spring compressor tools on either side of the spring (NOTE: There are many different types of spring compression tools, most of which will not fit in the tight confines of the LX platform front suspension).

Make sure the number of coils between the clamps is the same on each side. Tighten the clamps equally until the spring is loose.



(NOTE: The compression tools must be installed with the drive nuts on top, but fitting a wrench in this position can be difficult. One trick is to install double-nuts on the bottom of the thread so the screw can be tightened from the bottom of the tool)



(3)- STRUT REMOVAL
The shock and spring assembly (strut) is held in place by:
(3) bolts on the top shock tower,
(1) bolt through the lower control arm,
(1) bolt attaching the sway bar.

Once the coil is loose, the bottom bolt in the control arm can be removed.



It is best to remove the shock from the top mount before removing the three bolts holding the shock mount to the tower. This requires an offset 18mm wrench and an 8mm socket. Hold the shock shaft from rotating with the 8mm wrench, and loosen the 18mm nut.
Note: The 18mm wrench shown here is not properly offset to allow for complete engagement with the nut.



Remove the three shock mount bolts.



Remove the nut holding the upper control arm
Use a Ball Joint Separation Tool (pickle fork) to break the spindle from the upper control arm. This may require several heavy blows; don’t hit your fender!



Alternate method to separate the ball joint as suggested by pmpn8ez:
1) unbolt the caliper and pads from the rotor and remove out of the way in order to make clearance room.

2) use a large pry bar and wedge between the frame and lower control arm.

3) push down on the bar (dont worry, it wont break!!!), this will bring the whole unit downward giving you enough room to wiggle the whole shock assembly out from the upper and lower control arm unit.

Once the spindle is separated from the control arm, the bolt holding the sway bar can be removed .

(CAUTION: the sway bar will be loaded from the other side, so will be trying to push this bolt upward. Use care when removing!)



The shock/spring assembly can now be removed.

(4)- COILOVER INSTALLATION:
Remove the upper shock mount and rubber pad from the original shock and install it on the new spring. Slide the spring and mount onto the new KW shock and install the top nut to hold things together. Adjust the threaded spring perch following the KW instructions.



NOTE: the front assembly can be installed without compressing the spring if the perch is positioned as low as possible. The perch can be repositioned after the assembly is installed

Install the new assembly into position in the car.



Raise the spindle and reassemble it to the upper control arm. The ball joint will spin when you try to tighten the nut, so you may have to hold the control arm down to lock the tapered shaft of the ball joint in place to stop it from spinning.
USE CAUTION NOT TO DAMAGE THE UPPER CONTROL ARM !!



Install the lower control arm bolt, the sway bar bolt and the three upper shock mounting bolts and tighten securely (refer to manufacturers recommendations for torque values). Tighten the top nut holding the shock to the top mount.
Be very careful not to strip or damage the nut or especially the shock rod.

Follow the KW instructions to adjust the rebound rate (V2 and V3 only).
Mount wheel and lower the car (NOTE: the car will sit lower now, and there may be interference with the floor jack. Placing a 2”x10” under the tire before lowering the jack will allow for extra clearance).

Repeat for other side.

(5)-REAR SUSPENSION - SHOCK REMOVAL:
Block the front tires and raise the rear on the side you are working. Install a jack stand adjacent to the floor jack to distribute the load and improve stability. Remove the wheel and place it under the “frame” of the car.
The shock must first be removed to access the spring.

~~~~~~CAUTION~~~~~~

THE REAR SHOCKS ON THE SRT8 ARE GAS CHARGED. THIS COMPRESSED GAS WILL CAUSE THE SHOCK TO EXPAND RAPIDLY AND CAN CAUSE SERIOUS INJURY. THE METHOD THE OWNER USED TO RETAIN THE GAS-CHARGED SHOCK IS NOT AN APPROVED METHOD AND COULD RESULT IN INJURY IF DUPLICATED. THIS IS SHOWN FOR ILLUSTRATIVE PURPOSES ONLY

The shock cannot be removed unless held in a collapsed state, or without disconnecting the lower control arm. Since the inner bolt holding the control arm is installed so that it cannot be removed without first removing the exhaust, I chose to use a retaining wire to hold the shocks in a collapsed position.

The way I did it:
Remove the lower bolt mounting the shock to the lower control arm.
Remove the two upper shock mounting bolts. Use a 6’ pry bar between the control arm and the frame to assist in lowering the lower control arm below the “natural state” (BE CAREFUL NOT TO DAMAGE EITHER THE FRAME OR THE CONTROL ARM!). Insert a pry bar between the top shock flange mount and the body to create enough space to thread a 10-gauge wire through each of the bolt holes. Wrap two more wires around the lower shock rod, below the shock body.
Use a second floor jack to raise the lower control arm and compress the shock (place the jack “cup” under the shock; do not jack linkage, ball joints or other suspension joints).
Raise the control arm until the cars weight begins to rise off the frame jack. Tie the wires together. Do not fatigue or over-tighten the wires.






Lower the jack under the control arm. Inspect the wires (USE SAFETY GLASSES!).
Hold the suspension down with the large pry bar and remove the shock (BE CAREFUL!!)

(6)- REAR SPRING COMPRESSION:
The individual spring compression tools used on the front coils will not work on the rears. A hinged external spring compressor must be used to fit within the tight confines of the suspension (NOTE: the compression tool shown here is not typically available from rental shops, and the larger model more easily found will not fit… arghh!)
Install the hinged compression tool and compress the spring.




Remove the spring from the car. Remove the upper rubber pad along with the spring.

(7)- NEW SPRING INSTALLATION:
Install the compressor on the new spring. The spring must be positioned in the tool so the lower end of the coil is in the same position as the “pocket” in the rubber pad resting in the lower control arm.



Install the KW threaded coil perch on the top of the spring. Adjust the perch to the preferred setting (NOTE: I threaded the nut to within 3/16” of bottoming out and the rear was lowered only 1.2”, but some settling is expected)

The threaded perch sits into a recessed pocket in the car and cannot be adjusted without compressing the spring again, so set the position as accurate as possible!

Install the compressed spring into the car. Make sure the coil position matches the sculpted rubber base pad; remove and adjust if necessary.



NOTE: the threaded rod on the compression tool may hit a secondary suspension rod attached to the lower control arm. Removing the mounting bolt may be necessary.

There is a brake sensor line connected to this rod and can easily be damaged by the compressor tool. Remove this line from the clips and check it often to make sure it is not being damaged by the work.



Loosen the compression tool and make sure the spring is sitting properly in position.

(8)- COILOVER ADJUSTMENT:
Using the KW adjustment knob, adjust the rebound rate on the KW shock to the preferred setting (KW Variant II only).
Raise the shock into position and install the (2) upper mounting bolts.
Place a second floor jack under the lower control arm and raise the arm until the lower shock assembly bolt can be installed. Tighten securely.
Install the bolt holding the secondary suspension rod.
Tighten all assembly bolts to the torque rating recommended by the manufacturer.
Install the wheel. Lower the jack and re-torque the lug nuts.

Repeat for the other side.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~

(9)- EPILOGUE
The car will not sit properly until you drive it, as the raising and lowering of the jacks will preload the tires and not allow the car to sit “square” to the pavement. The coils will also settle between 1/4”-1/2” in the first few weeks of driving, so a second adjustment of the spring perches may be necessary.

The suspension will need to be professionally aligned after the heights are all final or uneven tire wear and handling irregularities may result.

Listen carefully for any knocking or clunks when driving, which could indicate a loose part or assembly bolts not properly tightened.

happy, happy, joy, joy.






NEXT: How to repair a broken front spoiler because your new lowered ride sits too damn low…