Applies To: 1991 - 1997 Volvo 850
Is your 850 sagging low to the ground? Is it bouncing up and down as you go over bumps and generally feels like a boat on water? Then you need to look at replacing some of your suspension components - primarily the springs, struts, and shocks. This how-to guide will walk you through replacing the rear springs and shocks on your 850. The steps shown are done on a 850 wagon but most of what you read here can also be applied to the sedan. The only difference between the wagon and the sedan is a slight variation on how to access the top shock mount bolts. Let's get started.
1. Raise the rear of the vehicle with a jack and support it with jack stands.
2. Open up the back of the car and remove the first floor panel (green) by lifting it up by the handle and then out. Continue by removing the side panels (cyan). They are held in place with clips so you will have to pry them up and out. Lift up the second floor panel (red) by the handle and continue to the next step.
3. Once you have it lifted up, find the two bolts that secure it to the frame and remove them (green). These are 10mm. With the bolts out of the way you can remove the panel.
4. Now that all the covers are out of the way you can see the shock mounts and the bolts that secure them. If you have a sedan, the mounts and bolts are covered by some carpet which you will have to remove after taking off the plastic side panels. Continue by taking out the two bolts from each mount. If you live in an area where your car is exposed to a lot of road salt then you may want to spray the bolts with some rust penetrant first.
5. It's time to remove the bottom 18mm nut on the shock absorber (green). Again, it is a good idea to spray this with rust penetrant first. Once the bolt is off, lift the suspension up a little with a jack to unload the shock and slide it off of the stud. You can then take it up and out from the cabin of the car.
6. To remove the actual shock from the mount you will need something to hold the center rod while you unscrew the nut. Look in the photo below to see an example. An offset wrench is used to undo the nut while the center rod is held in place with a vice-grip. Center nut is 15mm. You can then install a new shock mount on the absorber or transfer your old one. Either way the torque for the center nut is 30 lb-ft.
7. Now it is time to remove the rear springs. You will need to use a spring tool to compress the springs and remove them from the car. There are a few version of the spring tool but the most basic version consists of some rods with metal hooks on them. The hooks grab the spring while you turn the rod with a wrench. This tools is not the most user friendly and turning the rods with a hand wrench takes a lot of time. An air tool is a tremendous help here. Hook up the tool like you see in the photo below to compress the spring.
There is also a metal retainer on the bottom of the spring that prevents it from moving. It is secured with a nut. Remove the nut (green arrow) and you will be able to slide the spring out.
8. Here is a shot of the rear spring removed. Go ahead and loosen up the spring tool and transfer it over to the new spring. Also notice the rubber end and the bump stop - unless you bought new ones, you will need to transfer these to your new spring. I also had to glue the bump stop back to the plastic assembly because it fell off.
9. Here we have transferred all of the old parts to the new spring and we have compressed it with the spring tool. Time to reinstall everything.
10. Install the spring and the shock absorber. As you can see in the photo below, I have used the bottle jack to raise the rear suspension a little bit - you will have to do the same in order to slide the new shock on to the stud. Tighten the nut on the spring mount to 30 lb-ft. Tighten the shock absorber top mounting bolts to 18 lb-ft and the bottom nut to 60 lb-ft.