Tools needed:
- 19mm socket to remove wheels
- 15mm socket for bolt that connects shock to lower control arm
- 13mm socket for bolts that connect upper shock mount to the body
- 17mm pass through socket (or offset box end wrench) for original Volvo top nut
- 15mm pass through socket (or offset box end wrench) for Bilstein B6 top nut (this may vary)
- 5mm hex for counter hold
- At least one jack and a jack stand
Steps:
1. Chock the front wheels, break loose lug nuts and jack up car at the jack pad to remove wheel. Be sure to place a jack stand under the car as well.
2. Once you have the wheel removed, you will see the strut and the mounting bolts you need to remove.
3. Place a jack under the control arm and compress the strut to make removing the bottom bolt easier.
4. Remove bottom bolt (15mm) connecting the bottom of the shock to the lower control arm. This bolt threads into the control arm and can be fragile (ask me how I know….) so be careful with your use of an impact gun on this bolt. It might even be smart to just get two replacement bolts when you order your struts to have on hand.
5. Now remove the 4 bolts (13mm) connecting the top of the shock to the body. A small extension here makes it easier.
6. You can now remove the shock. Unless you ordered replacement parts (or shocks that come with the new mount already), you will need to remove the top placstic cap, the mount, the bump stop and the dust cover for use with the new shock.
7. Start by removing the top plastic cap to reveal the top of the shock and the nut that connects it to the mount. In my case, the nut has basically fused to the threads on top of the shock and it broke when I tried to remove it. If you are going from stock XC90 rear shocks, the nut should be 17mm with a 5mm hex to counter hold. You will need to use a pass through socket or an offset box end wrench to remove it. I show pictures of this on reinstallation, but as you can see from the image below the threads on the top of the shock split apart when I tried to get this apart.
To remedy this, I chiseled the threads away and then drilled the rest out to remove the mount and the other hardware from the old shock.
8. Once you have the old shock and components apart, you will then transfer over the bump stop, dust cover and mount to the new shock. You will need to tighten the nut on top of the shock to connect it to the upper mount using the passthrough socket and counter hold. In my case, the nut for the Bilstein B6 top was 15mm. Vida gives a torque value for this but unless you have their special tool, I’m not sure how you would actually torque it properly. I just went until it was bottomed out and did not overdo it.
9. Place the plastic cap on top of the mount and you are now ready to reinstall.
10. Start by reattaching the upper mount to the body. These are 13 mm bolts and will be torqued to 70nm. I did not tighten these completely until I had the bottom bolt started but torqued them before tightening the bottom bolt.
11. Now you can reattach the bottom bolt. In my case, I had to remove the jack from under the control arm first because I could not push the it up with the stiffer B6 shock. Letting it down allowed it to be much easier to thread the bolt. Do not use an impact on this bolt, it will break on you. When you have it threaded in loosely, you will need to jack the bottom of the control arm at the same point as above again until you are in the normal riding position (I went until the weight of the car was on that jack).
Once you are in normal ride height, you can torque down the bottom bolt. According to Vida, this should be 90nm and then an additional 150 degrees.
That is it! Now do the other side.