In reference with my previous thread regarding the weird vibration that happens at our AWD cars. The link: https://forums.swedespeed.com/showth...Issue-SPA-2018.
I finally discovered the whole issue of this vibration. Changing the propeller shaft CV joint and the changing the tires did not resolve my vibration issue. Initially, after the dealer changed the front CV joint in the propeller shaft and advised to change the out of round tires was the solution for the whole vibration, however, after buying and installing the new tires the vibration didn't go away.
This frustrated me so much and I decided to video and record the propeller shaft movement while driving the car. Guess what!! The propeller shaft is moving like the egg while driving the car . No doubt that this will create the weird vibration in the car. Now, in such situation the whole propeller shaft has to be inspected, corrected, and balanced and that should do the trick. However, Volvo should intervene and fix the whole issue of my car and of course under warranty. I'm not paying any single dollar out of my bucket. I have paid enough for my trips to the dealer, balancing, and tire changes .
After this issue, I do not think an AWD car is worth it. It's just a mess and very costly in repair just like an air suspension. If it breaks, I will dumb everything in the trash and drive my car FWD. My previous S80 didn't cause me such troubles even after driving her for 170K miles.
To check your car (at your own risk), there are two ways:
1- Video recording while driving (ensure to use a proper mount and use reliable Jack Stands... Your safety first)
2- (Not advisable and not recommended) Lifting the car (the whole four wheels) and driving it in the air only by maximum 25 MPH. However, you have to disable the traction and expect the ABS and TPMS lights to illuminate in the clusters. They will turn off automatically after you drive the car on the ground more than 20 MPH.
Update 2: My discovery today confirmed why the propeller shaft is circulating like an egg. It turned out the donuts (bearing) that hold the propeller shaft are in complete disaster causing the play in the propeller shaft. I'm really not sure when this rubber was broke. Very bad quality rubber. This type of rubber should last more than 100K miles not 1000 miles. Sorry Volvo but you have to recall all the propeller shaft in the market now and ensure the rubber is very strong and will last at least 100K miles. We have wasted enough money in dealer trips, tires, and balancing.
Anyway... Enjoy watching the below two videos...
Video 1: The propeller shaft movement while driving the car...
Video 2: The broken rubber in the bearing of the propeller shaft...
Here is a video that explains the balancing of the propeller shaft and how it must be perfectly round and straight: