V70XC awd 1998 vibrations at 120km/h

[850 LPT]

I did some research and found instructions on how to do it
I need the mounting plate 999 5971. I will just make it myself
But then i need balancing clamps. Any idea where i can get them? Or how can I balance it without those clamps?

You are on the right track with this. Measuring the runout is key, but you need the special measuring equipment. Then you calculate the weight for the required balacing weights. Volvo used to sell the balancing weights as a kit, but that has been NLA forever. I used tire balancing weights on the VC in my old 98' V70XC and secured them with a very thin wire going all around, this was probably 8 years ago now. Not ideal, but it worked ok. I am sure you could find a more elegant solution if you put your mind to it.

[scot850]

What brand of tires are you using and how old are they? Have you had the rims check for being bent? I have had several P80 rims on cars I and others have owned that have been pot-hole bent and caused vibrations. These should be obvious when having the wheels balanced.

Wheel bearings and wear in the inner and out tie rods and worn suspension parts at the front and rear can cause this.

On AWD cars also check the following:

1) The mounting support bush at the front of the Viscous Coupling unit
2) The bearing at the front of the VC unit (I had one fall apart when removed).
3) Have the balance rechecked on the prop-shaft. Volvo used to have different mounting bolt lengths for this to balance the shaft.
4) Try running the car without the prop-shaft and see if the issue is still there.
5) There are many bushes at the rear on the subframe several which are no longer available.
6) When the alignment was done for the wheels, are you sure they checked the rear as well?

Neil.

[Dzielnywojak123]

Thank you all for your help and ideas.
Today I changed my wheels to a second set and I can feel like it's a little bit better. The tyres I had before were Pirelli 215/45 R17 from 2021. I had them on a balancing machine and saw that they are straight (unless there is a problem with them under load).Now I have 225/55 R16 tyres on OEM rims. Because I feel the car is shaking less I suspect someone did a bad job with the brakes (they are almost new but I feel some runout through the brake pedal).

My idea is that if it were the propshaft or the VC the shaking wouldn't change with a different set of wheels.I'm going to order a dial indicator (which will also help me with balancing the VC) and check the runout on the brake discs. If fixing the brakes doesn't help, then I will check all the things scot850 told me to. A few weeks ago my car had an inspection and they didn't find any play in the suspension so if it is a suspension issue, I don't think it will be very obvious. And to answer your question: yes, I'm sure they did the alignment on the rear wheels because they showed me the printout with the alignment before and after.

I think I have enough things to check for now. I will update this thread when I make any progress with the car