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

[cn90]

Your other option is to go to a hardware store and try diff nuts until you find one that fits.

[cn90]

If I have to guess the size of the lower mounting nut (the 18-mm nut under the car), then it is:
M10 x 1.5 type of nut. But this is a pure guess.
Maybe Lee can help.

[Ozark Lee]

Off the top of my head I don't know but I think my plan would be to take off the other one and then match it up for diameter and thread pitch at the hardware store. Long term you really need to get a grade 8 or better nut. It needs to be torqued to 59 lb/ft and that will likely strip out the cheap Chinese steel that most hardware stores sell.

...Lee

[JimBee]

I add my thank you for this writeup

[lhailah]

hey there, long time reader, first time poster.

I bought some sachs rear shocks for my 1998 XC70 a few weeks ago. I heard the Chiltons manual was close to useless and Haynes doesn't cover all wheel drive systems. So I've ordered a "oem manual" from ebay which is still in the mail.
In the meantime my right rear shock is in bad shape and i'm sick of the drive. I think I can actually feel the car leaning back there.

I plan to get busy replacing them this saturday with my dad but I just wonder will this wonderful step by step apply to the XC model as well?

[Wrenchinjoe]

Thanks for the great write up cn90!

The trickiest part was indeed the rusty shock mount bolts, but your advice really helped me. I used PB Blaster the day before, just prior to removal I coated the bolts with grease, and just took it slow and easy... a couple turns loosen, one turn tighten. It was slow going and it was hot outside, but little bit by little bit all four bolts came out clean.

There was some corrosion on one of the lower shock studs, but a wire brush cleaned that up quite well. I put a light coat of grease on the lower studs as well as the upper mount bolts during reassembly and torqued everything down to spec. Thanks again for a very helpful tutorial.

[cn90]

Glad I could be of help.

I wish someone had told me this before I did this job.
For me, it was an agonizing 3h trying to extract the broken stud!!!

Anyway, Drive Safely...

[FlyingVolvo]

I take it that this repair is probably a whole more more complicated for an AWD model? I think the shock still comes off the same-ish, but the springs look more difficult!

[Lady-do-it-herselfer]

Thanks for the write up! And yes, even with your warnings, I sheared a top bolt. And then when I was hammering the bolt retractor in the pilot hole, the nut fell off the car! I fortunately did not have a rust issue on my 149K, 16 year old 850 GTL Wagon thanks to it's first 134K being in New Hampshire where they do not use salt on the roads like we do here in the Buffalo, New York area! It was almost a sin how easily I removed the lower bolts! I messed up by not evenly removing the bolts, which is the reason for this posting. My suggestion to the next repairer is not only to alternate between the two 12mm bolts on each mount, but to alternate between all 4 bolts (both the left & the right shock mount) evenly. Even with my small 120lb frame inside the car, it was still enough uneven stress to bend both bolts on the other side, ultimately shearing one. But if you do find yourself in the same sheared-bolt situation, put the other sides 2 bolts back on in an even position (first cleaning and spraying them with white lithium grease). This helped me get the fourth, un-sheared bolt off easily, even though it was bent.

I also included a picture of the rear, forward decking; I struggled a bit due to not knowing there were 3 retention brackets(pictured). After you remove the four bolts fastening it to the cars frame, slide the decking towards the rear of the wagon til all three brackets are released. Hope it eliminates the frustration like I had for 5 minutes wondering what the heck was going on?!

Another post in this site that helped was '97 Volvo 855 Wagon Rear Shock Absorber DIY tutorial by jreed; direct link is: https://www.matthewsvolvosite.com/forums ... 15&start=0

Picture of the 3 retention brackets on rear decking; shiny items in picture

Volvo rear decking.jpg (201.52 KiB) Viewed 3205 times

I also did not jack up the car like jreed suggested; didn't find a need to. Thanks again guys!

[LamboSE5]

Hey guys.

Hey - Thanks again cn90 for this.

I got it started today. Taking all of the advice here and in another write-up.
I had sprayed the tops of the shock mount bolts a few weeks, if not a month ago. I sprayed them again, then jacked up the car and found the underside/nut(s) and gave them a spray (wear glasses), and started to slowly and very carefully loosen the bolts from inside the car. I'm a patient guy, and this definitely called for it - I was ready.
That said while slowly, carefully loosening the very first bolt i felt this quiet "tick", a small break. I knew the bolt hadn't broken (man I was being so gentle and slow), so it had to have been the nut on the underside, further inspection showed that was the case. It had only loosened maaaybe a couple turns.

Anyway, this went really well aside from that. I got the other three out with a combo of lossening a few turns, then tightening a few, or all the way, spray liquid wrench/similar, repeat...even tapped bolts VERY lightly in different directions. You can see the penetrating oil seeping down the bolt threads, if you're lucky, and not pooling in the recess around the bolt. Look for that. Loosen, tighten, loosen more, tighten...repeat.

Quick Q's
1. So, the one nut I had break off - it's not a big deal at all - is it? I mean, I don't HAVE to weld the new one in place....do I? ( I read the suggestion in the cn90's after thought - just wanted to ask anyway) Just have a helper hold the nut while I fasten the new bolt...?

2. The bolts (3) I got out, I cleaned up with a brush + cleaner, then applied anti-seize, and put'em back in. Won't be finishing the job till tomorrow or next day. Do you think I should just go get all new bolts and nuts (don't care about the cost)? There is a bit of ... wear on the old bolts threads.

3. The bolt & nut where the nut's weld broke...I don't need to worry about that for the next day or so do I? AND I was planning on cutting off the old nut or bolt head with my dremel -- sounds good right?

Thanks a lot,
I can't wait to get new KYB shocks and OEM mounts in there this week. Anyone used the KYB's yet? I got'em off FCP.