C5 X7 driveshaft failure with vibrations

[Old Nick]

Hi everyone,

This is for information. It is about my C5 X7 but could be of general interest.

My C5X7 got the typical nasty clackclack. It was when turning left, and the right outer boot had been changed or reattached before I got the car. As a temporary repair I filled it with MoS2 grease and it became quite quiet.

Then I noticed some heavy vibrations over 80kmh driving uphill. They seemed to come from the front right but you cannot be sure when you are in the car. There were engine problems too, so what could it be? Engine mounts? Engine misfire/imbalance? Wheel damage/imbalance? I checked and ruled them all out, leaving some unknown link to the engine problems. The vibrations got worse and I noticed that it only happened only under load or engine braking, not coasting. I started suspecting the driveshaft and changed all of it instead of just the outer CV joint.

800 km with the new one now and no vibrations. So, if vibrations are only under load and engine brake, but not coasting, check the driveshaft.

[mickthemaverick]

Thanks for that tip, it may well help someone in the future!