I thought about posting this in the car audio section since that is where this comes up from time to time but think it should be in the interior section. I am really surprised nobody else has done a write-up on this - although I guess it could have been lost in the forum crash. Anyway without further interruption let’s get started!
For years I have wanted to remove the trunk springs and replace them with gas shocks. I did some research way back when and found a post on a Honda forum that gave me some ideas – just needed the motivation to give it a try. The torque springs do work great but they always seemed to be in the way for the many stereo ideas I’ve had. I’ve always managed to find a way to work around them but with my newest install plans, they had to go.
I ordered everything from www.mcmaster.com
and it shipped within a couple days. Below is a list of the items you’ll need and shipping should only be ~$15. Total money required for this project is around $80 provided you have all the necessary tools.
(x2 @ $18.32 ea.) PN: 9416K382 – Gas Spring w/threaded ends, 50 lb force 26.38” extended length, 10.24 stroke
(x2 @ $1.03 ea.) PN: 9512K92 – Ball mount hardware, 90degree angle long neck ball bracket
(x2 @ $2.96 ea.) PN: 9416K79 – 10mm ball socket, M8 thread
(x2 @ $2.17 ea.) PN: 6465K63 – Eyelet for male M8 thread
(x2 @ $6.68 ea.) PN: 9416K29 – C-style eyelet bracket for .32” diameter
(x6) ½ inch long ¼ - 20 bolts
(x6) ¼ -20 nuts
(x12) ¼ washers
Open your trunk and prop it securely with a broom handle or other stick. Nothing is more embarrassing than yelling for the wife to come and let you out.
The springs are under a lot of tension. You need to be very careful removing the since they have the ability to cause damage to both you and the car. I used a ¾ in box wrench to leverage on the end of the spring to unseat it from its hanger. You have to force it up and over to get it to release. You then can fish it out of the opposite side and repeat everything for the second spring. With both springs removed the only thing holding up your trunk lid is the stick!
Next you have to remove the lever the springs were attached to. Using a ¼ inch drill bit, drill the end of the long rivet until it is free. There is no real easy way to get to these so just be patient. The driver’s side is easy but the passenger’s side was a bear. I had to force the bracket off by prying on it until the pin had enough room to get free. You can see the end results of this step below.
The next step is to secure the angle bracket to the bottom portion of the rear seat. I used 3 bolts per side with washers both front and back because I know there is a lot of stress created and wanted as much surface area as possible. I thought of using a backing plate for additional strength but this appears to be plenty strong. When the brackets are installed, there should be ~1/8 inch clearance between the shock body and the rear fender well. The bottom of the bracket should be against the floor and far enough over to sit on the flat area.
The brace that goes from the hinge bracket to the wheel well needs to be bent a little bit. A few blows with a hammer is all that I needed to do to get the clearance for the shock body. Below you can see the end result.
Now it is time to mount the pivot bracket to the trunk hinge. I drilled a couple pilot holes and used self tapping sheet metal screws. In the future I might use bolts/nuts but the screws seem to be working just fine for now. As for the actual location of the bracket, I mounted it ~3/4 inch just aft of the concaved bend in the hinge. You can also see the orientation of the bracket with the pivot being placed furthest from where the shock would mount.
Next you should install the shock ball into the 90 degree bracket and secure it with the ball clip. According to what I’ve read the shock should be mounted in such a way that the shaft sits higher than the gas cylinder. You can install it anyway you want but figured I would pass the information along.
It’s now time to attach the pivot to the pivot bracket. This is very difficult because you have to force the shock to compress while trying to slide the pin through. It took me quite a while to accomplish this but it is possible. What I found is using a socket on the end of a screw driver allowed me to push the pivot all the way into the bracket. It can be done so do not give up.
The last thing to do is to make sure everything operates smoothly. Check your clearance with the brace and the shock body, look for any binding/contact problems and verify the trunk will close completely without bottoming out the shock.
I chose to use two 50lb shocks because I did not want to put more stress on components than absolutely necessary. The trunk will stay where ever you place it and closing it is a piece of cake. Good luck and I hope you all find this useful!!