replacing 1 cv joint ok, or is 2 recommended?
 

Hello l just replaced the drivers side cv axel in my xc70 , since i got it back ,when I take it on the highway and accelerate it up to 10km or so there is a vibration that I never felt before I put the car in, ShouldI have replaced the passenger side too ? or is it something else ?

nothing I know of says you should replace axles in pairs. What was your reason for changing the axle in the first place?

My car was making a clicking noise ,that was getting worse after almost a week ,so after inspection, the boot on the joint was blown wide open and needed to be replaced asap .So I got the whole new part replaced , now I did that and still I have a problem , no further ahead it seems, and is bugging me. I never ..in any vehicle I have owned replaced ,or, had to replace cv joint before ,its all new to me . the car is older its a 2002 I've owned it for 4 years it has 438000 kms on it , (motor was replaced by previous owner at some point ) It runs well ,and has served me well I want to keep it ,Probably the best used car I ever had .

did you replace the entire axle or just the CV joint? I'd doubt if the other side would suddenly act up immediately following replacing an axle so Id suspect the part or assembly is out of balance. Did you align the wheels after removing the axle?

I replaced the entire axel . It does not seem to have an alignment issue when I drive it . it goes straight I did just read its a good idea to do both for high milage cars . Thoughts?

I'd recommend a fresh alignment anytime there is suspension work which requires unbolting of a pivot point. For your second axle, you should inspect the boot as the first step - your first one probably would have lasted longer if the boot didn't tear or was serviced when it started to leak grease.