Shocks and Springs

This Wiki page was migrated from the previous FAQ section and may be somewhat out of date. For more current ideas on OEM shock removal, you might also want to check the Bilstein Shock Install Wiki Page.

Installing Koni Shock Absorbers

[CA] I have spent the good part of the morning installing the Koni yellows on my 94, I followed the Manual, Nicks directions as well as a handfull of other NSXer DIY’s (thanks for all the help and direction).

I have a couple of things to add to the obvious, I disconnected the sway bars until I was finished, they are not very easy to work aorund, much easier to move them. I also used a jack and a piece of wood to help compress the spring and dampner (shock) to help facilitate getting them into their mounts, this helped by leaps and bounds, especially on the rears. USE a spring compressor! one of my friends said, hey we dont need a compressor, so I sat back, had a coke and a smile and watched the fool.

I was very careful around the sleeves, especially in the rear, and if using a pry bar, be careful of the brake fittings, it is very easy to over look these, and cause irrepairable damage (we did not).

If you do decide to go with Koni’s , give Mark Johnson a call as he makes an adjustment tool that is aluminum, and longer than the koni plastic one, very very handy.

An Airtool is very handy in disassmbly and assembly, especially the top nut, if you turn it the nut on the koni by hand, it will eventually spin, and there isnt a damn thing you can do, whereas on the stock shock, there is an allen head bolt.

I also used a way cool socket that has a hole in the top, where you can slide the socket and driver over a long bolt and turn it, this was great on the sway bars where I can put an allen wrench through the socket and driver, and turn the bolt at the same time, I have to get me one of those (they can be found at SEARS…CRAFTSMAN…ooh ooh OOHHHH!!)!!!!

I havent been able to tweak the sho…er dampners yet, but so far I have turned the knob 1 full turn, and it is almost too much for everday driving, meaning the cd player skips a bit, but then again the roads in Dallas…uh, suck! I will get a chance to tweak later this week.

So far I have RM sways, 17/18’s with 40 and 35 series tires, and a custom tire saving alignment ( I think needs a tad more toe in on the fronts) and now the Koni’s, it is starting to come together…it handles nice and flat withot beating you up. The Koni’s do not lower the car at all….btw.

Spring/Shock Replacement

[BSD] I was brave enough to try replacing the shocks in my NSX over the weekend. As you will have read on the list, most suggest not attempting this yourself because it is a difficult process.

Before I started, I called two local dealerships and asked how much it would cost to have the 4 shocks replaced (paying for labor only). One dealership said 2.5 hrs front and 2.5 hrs rear. The other said 1.5 hours front and 1.5 hours rear. The second guy upped his labor rate to $67 per hour to help cover any run overs. That amounted to $240 (somehow). The other was $360.

Here is the procedure most recommend for changing your shocks and/or springs on the NSX:

1) Call local dealerships for quote

 2) Schedule time for them to do work
 3) Drop car (and parts) off at dealership
 4) Enjoy rest of day

For those of you who just have to do it yourself, here is the procedure. This is for replacing stock shocks with Koni Yellows. We warned you.

Get "special" tools you need: external grab spring compressor, metric allen wrenches, cylindrical metal file or drill (12mm bit preferred). Note that I do not have the stock brake lines so you may have to move them during the process. In front you should probably remove the wheel speed sensor wires (which I left out below.)

Start in rear. Raise rear of car reasonably high and support safely (such as with jack stands.) Remove rear wheels.

Start on one side. Remove 17mm nut holding lower end of shock to lower A-arm. Break it loose with large ratchet or breaker bar. Then, use open-end wench to hold other side of bolt and remove nut completely. (The manual shows this clearly.) Use hammer and punch or something similar to pound out bolt through shock.

Remove sway bar to lower end of sway bar link. First, brake it loose. Then, use allen wrench in end of bolt to hold it while using open end wrench to turn nut. Or, use an impact gun with an allen wrench on end of it while holding nut with closed end wrench. This will take a while if you do it by hand.

Open glass engine cover and black engine lid. Remove black plastic trim on trunk side of opening. It has 7 Phillips screws. Loosen 3 shock top nuts (14mm), then tighten back till snug. Now, as manual says, remove shock assembly. Yeah, right. This is where you may refer to step 3) above.

The shock is way stuck in there. The first problem (I think) is that the bushings in the A-arms apply lots of torque to the suspension in the up direction. Although the shock isn’t pushing down, the suspension is pushing up. This makes it impossible to just lift the shock out. Part of the solution is to stand on the caliper and rotor and use your weight to push the A-arm down. This is why the nuts are still snug at the top of the shock… to hold it up while you stand on the A-arm. Hopefully, this will pull the lower end of the shock out of the lower A-arm. Yeah, right. Refer to step 3) above.

I spent about one hour jumping on the caliper and rotor to push the suspension down while I used my hands to hold on to the engine opening for balance (I’m 6’6" by the way.) I also used a hand to push, one to pull, another to lift, yank and pound the lower end of the shock out. I even stood on one foot and kicked. Nothing. Finally, I got my wife to help. I had her stand on the A-arm while I pried and pounded. But, she weighs only half of what I weigh which was not enough. So, we traded places. I stood (jumped actually) on suspension and she pulled and pushed or whatever it took to get the bottom out. Finally, it came out.

I left some detail out in the story above such as the fact that the CV boot is right next to the bottom of the shock and it where the shock wants to come out. Also, the upper A-arm hits the shock depending on how far the suspension is lowered. There are probably other things that are problems that I have thankfully forgotten. Further, the brake line is right there which may need to be moved or removed. Remove the shock top nuts (14mm) and don’t drop them. Then remove shock from car.

Disassemble shock. The spring compressors I used were external grab ones. They have a large long bolt that has hooks that thread up and down on it. I borrowed them from AutoZone, although Checker loans them as well… the same kind. Put them on as far towards the top and bottom of the spring as you can go. Then, tighten nut on end of bolt and the clamps will come together. Use one on each side of spring. Compress only enough so that spring is not pressing on spring top perch. My clamps worked like a champ and took little effort or time. I had an electric impact gun which make tightening and loosening them a breeze.

Be careful with compressed springs. The force is unbelievable, even if only compressed a little. This could cause major damage and injury.

Loosen shock top nut (19mm I think). Use impact gun and hope it loosens some. Then, use allen wrench in end of shaft to hold it while you remove nut. In other experiences with replacing shocks, this was the major pain. However, all 4 of mine came off with no challenge.

Remove top nut. Remove entire shock top (upper spring perch) which includes washer above top rubber bushing, top rubber bushing, large disk where springs rides under (spring top perch), another rubber bushing underneath, metal cylinder that holds bushings and spring top perch in place. These are all one unit, as far as removal and re-assembly. Make sure large rubber ring (where spring rides inside spring top perch) stays in spring top perch.

After all that is off, you can just lift the spring, still compressed, from shock. Gently set aside and don’t screw with it. This is a danger area.

Next, remove disk above dust sleeve. Then, unattach lower end of dust sleeve from bottom end of lower spring perch. Remove dust sleeve and metal cap at the top of sleeve. The hole in this cap must be enlarged to 12mm. I used a drill with a drill bit of about 6mm and had to work and work to get it drilled out enough for 12mm. This sucked as you really lose momentum during the project during this phase.

Remove washer and bump stop from shaft. Make sure bump stop is still in tact.

Remove lower spring perch from shock. Pound on spring perch from bottom towards top and it will finally come off. A brass looking cap will also come off. Discard this piece if replacing with new shocks.

Speaking of pieces you don’t need. You don’t need the metal cylinder that is/was between the two bushings that came off with the spring top perch. That gets replaced. So do all 3 metal washers (disk under top nut, disk between lower bushing but above dust boot cap and disk on top of bump stop.

Had enough fun yet? No, you haven’t. You are almost done with 1/2 of one shock.

Re-assembly: Put lower spring perch on to new shock. Put on bump stop (narrow side down; side with washer up) and one new washer. Put on dust boot with cap after enlarging hole in cap. Attach dust boot to lower spring perch. It is ok if this raises lower spring perch. Put on metal disk that rides on dust boot cap. Put spring back on (still compressed). Be careful. Align spring bottom with lower spring perch. Put on new metal cylinder sleeve. Put on lower rubber bushing. Put on spring top perch. Put on upper bushing. Put on upper disk (the one that is curved) and shock top nut.

You will have lots of problems with this part. For my front shocks, the metal cylinders did not side over the shock shaft easily. I used WD-40 and even used my drill to smooth out the inside. It may be hard to get the bushings to slide over the metal sleeve. It may be hard to get the new self-locking shock top nut down far enough. You have to get it down on the shaft far enough to expose the flat side of the top of the shaft. It is made for a 9mm wrench. For one of my shocks, I had to disassemble, then hold shaft somehow and use impact gun to get the self locking nut down far enough to expose flat part of shaft. The, I re-assembled, and the nut was able to go on far enough to get a 9mm wrench on the flat part.

Tighten shock top nut to like 37 ft lbs (according to manual). It smashes the bushings down a ways before it becomes tight.

Now, remove spring compressors. Do this evenly, although the spring is now captured and can’t go anywhere. Align top of spring with dents in rubber ring in spring top perch. The manual also talks about lining up spring top perch bolts (3) and bottom of shock in some confusing way. I was able to twist my shock even with spring in there to align shock

 bottom when I needed to.

Now, as manual says, replace damper assembly into car. Yeah, ok, it just fits right in. Begin wishing you had used step 3) above.

Get assistant (hopefully heavy) to stand on caliper/rotor. Put shock bottom near to where it attaches. Then, put shock top up through 3 holes. Tighten at least one of them most of the way. Next, spend the next 30 minutes jumping on caliper while assistant moves shock bottom. You want the heavier one jumping on suspension.

The closest we could get it to go was just resting on the lower mount. It was not in but aligned correctly and resting there. It seems the width of the Koni bottom is more than the width of the stock shocks. Then, I used a tapping device to tap and pound the lower part of the shock into its place. When I got it mostly aligned, I pounded the lower shock bolt through. The pounding of the lower bolt seemed to do the rest of the aligning. Then, replace lower shock bolt nut and torque. Replace sway bar to sway bar end link and torque. Remember, you have to use the allen wrench to hold the bolt while you put the nut on. This takes a long time and makes you wish you had used step 3) above.

I don’t think any more explanation on my part (such as describing the rest of the shocks) will help in doing this procedure. It took me from 9am to 9:30pm to accomplish this. I took a 1/2 hour brake for pizza and a 45 minute break/test drive when I had completed the rears.

Two days later, I am totally sore. My butt is almost bruised from sitting on the cement garage floor for 12 hours and all my muscles hurt. I smashed my hand countless times pounding on stuff and my back and neck are stiff from propping my head up so much to look at how stuck the shock is.

I have no idea how the dealership would accomplish this task. How can they hold the suspension down? Even if they could, it only goes so far and putting the shock in is still not easy. I bet they do not use the procedure in the book (and described above.) There has to be a missing step such as removing the lower A-arm or removing a ball joint… something to let the lower A-arm go much farther down while not dragging the upper A-arm down as well.

Happy wrenching.

[BSD] I just spoke to an NSX technician who gave me an idea for how to make the shock replacement easier.

He suggested to loosen the 3 bolts on the top of the shock first. The second time he described it, he said to just remove them. Then, when you raise the car, the suspension can really travel. This lets the shock hang in their loose at the top end and reduces any force on the sock due to the hanging suspension. Then, he said to remove the lower bolt (which holds the bottom of the shock to the U where the bolt attaches.) Then, he said to remove another bolt that holds the U to the A-arm. This will allow the shock to come out (possibly with the U) without any fuss.

[NM] I too noted the danger in doing the springs with the rear axle boot so close to the unbolted strut. For those who haven’t seen this, when you unbolt the rear strut at the bottom, it literally rests against the metal clamp that holds the rubber boot on. The easiest way to get it out is to move the strut towards the boot and away from the rotor, making sure not to tear the boot as it passes over it. The boot angles away and you can eventually remove the strut assembly. I was lucky as I took few precautions and even lost my grip and the strut assembly "fell" against the boot and the brake line.

[TWA – 2000/10/25] Although it looks as if you need to remove the four bolts that attach the upper control arm; you do not. The suspension will swing well out of the way by prying it down. These bolts are a real bitch to put back in if you remove them and they can be stripped….. so just swing the whole arm down out of the way…. That may be obvious to some, but other posts and do-it-yourself instructions say that you remove these….. don’t and save yourself some headache.

Do It Yourself