The car has a really awful vibration that comes and goes. Most of the time I feel a minor vibration. When it's bad it shakes the whole car, but not the steering wheel. I have jacked up the back end and checked for wheel bearing wear on both sides and did not find that to be the problem. There are no noises. Not sure what to check next.

 

WillWeb79, I have the very same type of vibration. In general I feel a slight, hardly noticeable vibration which I am sure is coming from the front suspension. However on occasion, I get very harsh vibration or shacking that affects the whole car and is felt by all in the car. Some people think its due to Torque Converter shudder, although it could well be I am not convinced 100%. Its almost like the slight front suspension vibration turns violent on some road surfaces. I have checked or replaced everything except the front struts, which because they are the expensive Four-C type I am not willing to do without being sure they are the problem.
I love the car (2006 xc70 with 168k) but the shacking is worrying and very annoying. I have a 600 mile trip today so fingers crossed.
lucky Pete.

 

you will need to do some experiments - if you feel the vibration, does it change if you let off the throttle or increase the throttle or if you are going up hill? is it still there if you dropped into neutral and coasted? Does applying the brakes make a difference? Does it happen if you are cornering left vs right?

I think there is also a fuse/relay for the Haldex (differential electronic module). You may want to see what happens if you remove that fuse... (check YouTube or google for more ideas on diagnostics for the differential lock system).

 

I had a v70 2.4 t and I had an issue where I had a vibration at a certain speed.below and above 65-70 mph it never happened.i suspected the passenger side axle and after I changed it out it was smooth as butter.....did you figure it out??? I m also asking because my xc70 has that issue but at lower speeds.id like to hear what your experience was if it got fixed!

 

Hi Unclebubba
I am afraid I have not yet resolved the shudder/vibration. I love the car but this issue is going to end up with me getting rid of it soon.
I drove it this morning and it did not drive too bad, but coming home tonight it was back to its annoying self.
when the shacking happens it sometimes feels like the front struts seem to set up some sort of high frequency un-damped bounce. Other times I think maybe it is Torque Converter Lock-up shudder.
I am thinking the problem is with the front suspension as I can feel a slight shake and vibration in the steering wheel almost all of the time, but nothing much. However given these are quality vehicles I don't expect to feel anything.
I have changed the transmission fluid, added shudder fix, replaced the transmission torque mounts top and bottom, replaced the vacuum engine mounts also the track control wishbones and ball joints.
I really would like to fit new front shock absorbers and top mounts but as mine are the 4C type they are very expensive and I am not willing to spend that sort of money when I am not 100% sure there is a problem with them. The car does not rebound more than I would expect and there is no sign of oil leakage from them. However I think they are the Gas over Oil type and clearly I would not know if they had leaked gas pressure.
not sure what my next move is to be. If I could be sure of removing the error message I would definitely try some standard shocks instead of these 4C things.

Lucky Pete

 

If you feel it all the time , I would look at tires and axles....have you ever gone around a curve in the road at higher speeds and feel it reduce? That's what mine does currently...but mine also goes away at high speeds..... Have you tried rotating the tires both fronts to the back and both backs to the front there's two things that will isolate the symptoms.... Something to consider that's you know it doesn't cost anything. The other thing is is I can get junkyard parts where I can inspect the CV axle boot on the part so if there's no break in the boot there's no grease it's leaked out so that'll be a good axle if you can get a hold of one for cheap or at the junkyard I'd consider switching out your axles just to eliminate that cuz that's a cheap fix too.

 

+1, also pay attention about road speed and whether its different when turning left or right (which will load up the wheel bearings on one side). Also put on your list to check motor mounts

 

Guys, my car is tho 2006 xc70 auto, therefore I only have 2 options on the 4c controls, comfort & sport, there is no advanced setting. If I swap out the front 4c shocks for new units will I need to calibrate the SUM? I'm not even sure I have a SUM and I don't own a VIDA DICE.
Lucky Pete.