850 Sedan Rear Shocks DIY

Post by **polskamafia mjl** » 26 Jul 2010, 09:41

This is a write up for the replacement of rear shock absorbers on an 850 sedan. Before doing this repair I would suggest you let the car sit for at least a night with PB Blaster or WD-40 sprayed on the shock mount bolts and the lower shock to trailing arm bolt. I broke one of the shock mount bolts and I spent the entire weekend trying to get it out. I eventually had to drive it to a mechanic with only one shock mount bolt in place on the passenger side!

In addition, take a look at these other links:

CN90’s great write up for Volvo V70 Rear Shocks DIY Tutorial
JReed's outstanding Volvo 850 Wagon Rear Shocks DIY Tutorial
My thread with a lot of 850 shocks questions

Note: I used OEM Sachs & Boge Shocks. If you use Koni or Bilstein some parts may be different.

Necessary tools:
Crow Bar
Cheater Pipe
Pipe Wrench
T-30 Driver
Flat head Driver
Crescent Wrench
Torque Wrench
Socket Wrench
Regular Socket Set
Deep Socket Set
Offset Wrench Set
PB Blaster
Anti Seize
Cigarettes

: Tools

Removal:

1. Remove 3 plastic floor fasteners

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2. Remove the seat bolt; a pipe wrench is handy to get it started while a T-30 will help finish un screwing it. [2]

3. Remove the 2 flat head plastic fasteners with a flat head screwdriver. [1 and 3]

4. Remove the plastic 10mm fastener. [4]

5. Remove the pop out fastener. [5]

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6. Pull back the carpeting.

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7. Spray some more PB Blaster on top of the shock mount bolts and from below. Also, apply gobs of anti seize to the bottom of these bolts so it will be sucked up into the nut as you spin the bolts.

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8. Slowly and carefully remove the 2 shock mount bolts with a 12mm socket. For the 3 bolts that I didn’t break, I used cn90’s technique. It works perfectly. Loosen it 2 turns tighten 1, loosen 2 tighten 1, etc… Periodically, if you feel a lot of resistance, stop, spray PB Blaster and let it set for a while then go after the bolts again.
Take my advice, DO NOT BREAK THESE BOLTS AT ALL COSTS! This is an easy job unless you break them.

9. Jack up the side of the suspension you are working on to relieve pressure on the shock absorber. Now, use the 18mm deep socket and cheater pipe to remove the 18mm bolt at the bottom of the shock. Be careful with this bolt as well because if you break the stud off you will have to buy a new delt link arm.

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10. Use the crow bar to slide the shock off of the mount.

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11. Lift the shock through the top.

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Reassembly:

1. Order of parts from top to bottom: Nut, Shock Mount, Shock.

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2. Hold the bottom of the shock in between your feet. With one hand take an offset wrench [for OEM shocks, it is a 15mm wrench] and with the other hand use a crescent wrench. Tighten the nut as tight as you can. Don’t worry about the torque value for now, it is much easier to tighten once it is in the car.

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3. Install the shock through the top. Dip the shock mount bolts in anti seize so the next time you need to remove them, they won’t break. Do not install these 2 bolts yet.

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4. With the suspension jacked up a bit, maneuver the bottom of the shock onto the stud on the delta link arm and loosely tighten the 18mm nut with a deep socket. I also sprayed this with PB Blaster for future endeavors.

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5. Now go back up top and tighten the center bolt to 29ft/lbs, then the shock mount bolts to 18ft/lbs, and finally, underneath, the 18mm bolt to 59ft/lbs.

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6. Now, clean any excess oil or PB Blaster off, replace the plastic fasteners and button everything back up.

Congratulations!

Remember to let the PB Blaster set over night and to apply grease from the bottom onto the bolts. Take it slow. They are a real PITA to get out. I spent all weekend trying to remove just one bolt and I still couldn’t do it.

Post by **matthew1** » 26 Jul 2010, 09:55

Beauty tutorial, polskamafia mjl! Added to Repair Database. Let us know how you like the Boges.

Post by **polskamafia mjl** » 26 Jul 2010, 09:57

The back end seemed a LOT firmer on my drive back from the mechanic this morning. Next weekend I'll be redoing my front end.

Post by **xHeart** » 15 Dec 2012, 18:22

This procedure closely matches my 1997 850 sedan.
I would remove the two rear wheels for better access from below. Therefore, what are the placements for jack-stands?
It will be Bilstein TC with Hutchinson mount fastened with replacement 10.9 grade zinc bolts.
Soaking overnight with PBBlaster.

Front rides straight and great. Would it need alignment tweaked?

Happy Holidays.

Post by **cn90** » 15 Dec 2012, 19:24

Actually if you back the REAR wheels on some wood ramps, no need to remove the rear tires.

I am doing this soon, am thinking:

1. Heat the 18-mm lower shock nut with propane torch to reduce the torque needed to undo the nut.

2. The shock mount bolts:
- Soak with PB Blaster for a whole week.
- I am not sure there is room from below but how about thread a nut from below just to loosen the rust buildup on the bolt threads?
Then undo the bolts. Does anyone know if there is enough room from below to thread a nut?

Post by **JimBee** » 15 Dec 2012, 19:59

Here's how I got those two top mount bolts out.

1. Use a small wire brush (slightly bigger than a tooth brush). I have medium hands and it's tight getting into the well, but I managed. Scrub around the bolt threads, with the threads, not across them. You won't get them perfectly clean but you'll clear off some of the rust fuzz. This took about 10 minutes. You might not think whatever you can remove will make a difference, but it did on mine. Remember those threads are zero clearance inside the bolt. Next time, I'll probably duct tape an extension on the wire brush handle.

2. Take a small ball of cotton. I save the wads from supplement bottles, just toss them in a zip loc for future use.
Soak it with PB Blaster. Put on a latex work glove and reach up in there. Get the cotton around the stud and squeeze the PB all over the stud. You can try shooting PB up there but it's hit or miss and you might end up with more on your face than on the stud. That's what I tried first. The cotton worked better. If you can recruit a kid with a small hand to reach up there with the cotton ball all the better. Just show them how to do it on a bolt that's off the car. I did it myself.

Those bolts were rusty, but after loosening with a wrench, they could almost ( I said almost ) be turned by hand the whole rest of the way. No problem. The fussy prep was well worth the 20 minutes to do it.

I agree about torching the lower cap nut. Mine creaked all the way. It's tough to get PB Blaster inside the nut.

Post by **xHeart** » 15 Dec 2012, 21:53

Once raised, there is ample room to reach the bolt from underneath.
I am using pieces from cleaning supply. it is sponge material. After slicing into 1" cube like shape, i used a drill bit to make a hole through it that is narrower than the stud, wet it with PB Blaster and then use screwing motion to wear it over the bolts, like a boot. Keep it soaked lightly. No squirts and drips, a desirable clean method.

I started the treatment (on and off) a week ago. All my 12mm bolts turned. I will put the socket to 18mm in the morning.

Backing the wheels on to the wooden ramp was unsuccessful, each time the ramp slid and moved. Scratched it.

Is there a better way?

Post by **Ben850** » 15 Dec 2012, 22:44

I did mine this morning. the right side came out easy, so I figured the other side would be as well. I broke the first bolt immediately.

I sprayed more PB on the top and bottom of the final bolt and treated it like tapping threads, moving back and forth a little at a time.
When I went back to make a punch dimple to drill out the broken stem, the nut popped right off the underside as if the weld was cold and barely took.

This actually made things easier to fix. I now had a clean surface on top and bottom for the new bolt.

I think it only added about a half hour to my estimated time. The ride is a world of difference and it made my decision to get TC fronts as well, instead of just the spring seats which I had intended to do.

Post by **xHeart** » 16 Dec 2012, 16:08

Passenger rear is fully installed and torqued.

12mm bolts are off. I am in trouble with the 18mm cap nut. It has turned two complete thread, i can see it. It made a piercing scream. I am worried.
Here are few photos.