DIY: 1998 Volvo V70 Rear Shock Absorber (BilsteinTC) & Shock

[cn90]

DIY: 1998 Volvo V70 Rear Shock Absorber (Bilstein TC) & Shock Mount

Here is a quick DIY for 1998 Volvo V70 Rear Shock Absorber + Mount.

NOTE:

1. The trickiest part of this job is in the bolt holding the Shock Mount. These bolts were rusted through and I broke one of them (it took 3 hours to get the stud out!). Learned my lesson, and the rest is easy.
The Nut is welded to the chassis.
- Once the car is safely on jackstand. From underneath apply some grease on the Bolt part below the nut. This way when the bolt is removed, the grease is sucked into the nut.
- Spray the top of these bolts with WD-40 or PB Blaster. Let it sit for 30 minutes.
Go and do something else in the mean time.
Then loosen these bolts about 2 full turns. Once you feel the resistance, this is when the rust is drawn into the nut. Stop here. Again, Spray WD-40 or PB Blaster generously around the bolt so it flows downward into the nut. Let it sit for one hour.
- When removing the bolt, back it out 2 turns, tighten it 1 turn. Repeat the process to get the bolt out slowly. Back and forth and back and forth to work the rust out. If you feel too much resistance, stop, apply WD-40 or PB Blaster and wait. This is similar to tapping a new thread (same idea).

2. The shock mount bolt is M8 x 1.25 x 30. Get a four (4) bolts at hardware store (or Volvo dealer) beforehand. Get four (4) M8 nuts in case the factory nut is stripped.

3. I use Bilstein TC Shock Absorber ($58/each) and Volvo Shock Mount (Corteco, $24/each). Got all my parts at http://www.rmeuropean.com. FYI, Bilstein Struts/Shocks are L.T. warranteed.
Very happy with the ride (I also have Bilstein TC as the Front Struts).

4. Torque values:
- Shock Absorber Top Nut: 40 Nm
- Shock Mount Bolt: 25 Nm
- Shock Absorber Bottom Nut: 80 Nm

5. You need an offset wrench (17-mm) for the Shock Absorber Nut. Sears carries this offset wrench! Another choice is Air Tool but be careful not to apply too much force, the shaft can spin and damage the absorber seal.

PROCEDURE:

1. Car in Park, Apply Hand Brake. Chock Front wheels!

2. Jack the Rear and place Jackstand under the subframe (where the delta control arms is attached to). Yes Jackstand under the subframe, and not under the control arms.

3. Open the trunk, remove flooring material. The Cover is held by four (4) 10-mm bolts, 2 on each side. Once this is removed the Shock Mount is in plain sight:

98-Volvo-RearShock-01.jpg (68.68 KiB) Viewed 25763 times

4. This is the setup: the bolt goes down. The nut is welded to the chassis:

98-Volvo-RearShock-02.jpg (59.95 KiB) Viewed 25763 times

5. If you replace both Shock Absorber and Shock Mount, no need to remove the single Shock Absorber Nut. Just loosen the 12-mm Bolts holding the shock mount, again read my tip above (Spray WD-40 or PB Blaster and work very slowly, back and forth many times to loosen the rust!!!).

6. The lower part of the Shock Absorber is held by an 18-mm nut.

7. To remove the Shock Absorber, jack gently under the Rear Spring to release tension on the Shock Absorber.

98-Volvo-RearShock-03.jpg (95.32 KiB) Viewed 25763 times

8. During Shock Absorber and Shock Mount assembly, note this sequence. From Top to Bottom:
- Large 17-mm Nut
- Large Washer
- Shock Mount
- Protective Sleeve
- Small washer (Bilstein provides this small washer)

9. Assemble the new Shock Absorber and Shock Mount outside of the car. It is much easier this way. Use the offset wrench and an adjustable wrench to hold the Shock Bolt. Tighten to 40 Nm.

98-Volvo-RearShock-04.jpg (97.01 KiB) Viewed 25763 times

10. Insert the new assembly into the car, install the 2 bolts loosely. Get under the car and attach the Lower part of the Shock Absorber using the 18-mm nut, do not tighten this 18-mm nut yet. Go back above and tighten the 12-mm mount nuts to 25 Nm. Then tighten the Lower 18-mm Nut to 80 Nm.

If you follow this DIY, it will be straightforward. Avoid breaking the bolt/nut at all cost!!! I spent 3h extracting the broken bolt!!! Anyway good luck and have fun, you will like the new ride from Bilstein TC!!!

Congrats, you just saved some money on labor for this easy job!

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AFTER THOUGHTS:

I search the different forums before doing this and I knew the nut/bolt on the mount is tricky and even so I broke one bolt off!!!

Having done this, my best advices for people are:
1. Get extra bolts and M8 nuts on hand.
2. Spray the bolts with WD-40 or PB Blaster 24-48h before doing this job.
This allows the lubricant to drip down into the nut's threads.
3. Then remove the bolt as mentioned above, 2 turns CCW and 1 turn CW.
Apply WD-40 or PB Blaster, wait 15 min.
Repeat the process as if you tap new threads using tap and die set.

Having said that, if you run into:

1. Broken bolt:
This was my nightmare, it took forever to extract the stud. Solutions:
a. Vice-grip to grab the stud and undo it.
b. Drill the stud out but you risk damaging the nut's thread.
If you stripped the nut's thread (but still welded in place):
- You can drill it larger for the bolt to pass through, then use another nut below it.

2. Broken Nut off the welding spot:
This is actually easier to handle than broken stud!
Working through the rear pass door, just place another nut below then install the bolt.
You may need another assistant to help you hold the nut while you tighten the bolt.

[jblackburn]

This is awesome, thanks for the time & effort you put into this cn90!

I'm going to add this to the repair database, I'm sure it will help a lot of people.

[Ozark Lee]

One other note to add is to be very careful when removing the lower mounting nut. We have had more than one member go after it aggressively only to have the stud break. At that point the only real solution is to replace that side of the delta link.

As tempting as it is to go after the lower nut with an impact wrench don't do it. A lot of PB Blaster and slow steady pressure with the ratchet or wrench should keep you out of trouble.

...Lee

[cn90]

This is awesome, thanks for the time & effort you put into this cn90!

I'm going to add this to the repair database, I'm sure it will help a lot of people.

My pleasure.
You would think that there is some decent DIYs for Volvo V70 rear shocks, but I found very few, if any, useful threads.
Therefore I decided to write this up.
I usually hang out more on Volvospeed forum (have been there more than 8 years) but I am migrating to this forum because the software here is easier to use.
Anyway, this is my 1st post in this forum.

[confused_al]

Nice write-up!
I brought a set of Lisle "Universal Shock Absorber Remover/Installer" worked well for me.
https://www.amazon.com/Lisle-20400-Unive ... 264&sr=1-1

[cn90]

Nice write-up!
I brought a set of Lisle "Universal Shock Absorber Remover/Installer" worked well for me.
https://www.amazon.com/Lisle-20400-Unive ... 264&sr=1-1

Hi confused_al,

The Lisle Tool 20400 is 15mm and 9/16 hex and only works for stock OEM Shock (which is 15 mm nut).
The Bilstein Shock uses 17mm nut so an off-set wrench is absolutely needed.

[confused_al]

Thanks for pointing it out, I forgot to mention I replaced with Sachs/OEM shocks.

[checkxp]

Hello there, thanks for the very explicit DIY.

I just have a little question concerning the Bottom Shock Absorber Nut. I got my car serviced yesterday, and he pointed out the nut was missing on the right side. As I just purchased the car a couple of weeks ago, I only became aware of this yesterday, but he told me he didn't know the size of nut it was, and he didn't have one in stock (bad workshop I think, lol). I would therefore like to put a new one ASAP, but he told me it wasn't a major critical issue.

My question is what are the exact details for the nut (if you know them), it's an 18mm nut, but what thread, and thread depth? So I can go and buy it, and I shall replace it the way you said, by moving in very slowly. (I have a 1996 850 2.5 20v, I guess it's the same nut).

Thanks a lot for your help. I just became owner of a volvo, and I must say I am really proud, but I hope I didn't buy something badly maintained. It had a (perfect) service history until 120k miles, and now has 147k 2.5 years later. The plastic in the trunk also seems to make a lot of noise (it's an estate), any suggestion on how to reduce this?

Thanks

[cn90]

Why don't you go to your local Volvo dealer and get the nut, it should be cheap?

[checkxp]

That was my plan, but I won't get one open until Tuesday or Wednesday where I live, so I thought getting one from a DIY shop would be quicker, as I plan a 500mile drive tomorrow, but I don't think it'll be too much of an issue.
Thanks anyways.