Please help! Possible driveshaft issue or something more/less sinister?

[Morgen]

I have a very very VERY VERY VERY annoying issue:

When driving at 50mph+ I start getting a horrendous vibration through the steering. At around 60-70mph it's so violent that the arm rest can actually be felt juddering from side to side and the steering wheel is quite difficult to hold comfortably. The car first did this back in September 2015 after receiving it back from a garage (was in for 2 rear control arms and a full alignment) and I assumed it was a wheel balancing issue so in October the wheels were finally balanced and the problem was still there. I took the car back to the garage that did the initial work and they checked it over... On the phone they said it sounds like a driveshaft problem so that's the first thing they checked. Absolutely no play in either shaft, and all the suspension appears sound. They suggested I raise the car as it was stupidly low, and this should eliminate my issue somewhat. I raised the car a few days later and they were correct, problem resolved to a standard I was comfortable with. However, it's back with a vengeance 

I don't know what to do - there's still absolutely no play in either shaft! I don't want to go replacing them and it turns out to be something else, but no garage has been able to pinpoint anything at all wrong with the car.

People have suggested the tyres but both fronts are brand new and have been changed during the time period this problem has occurred.
The wheels being buckled has been another suggestion, so I'm going to swap the front wheels to the back to eliminate that option.

Has anybody else had this problem? I'm trying to get to the bottom of it with no luck! The cars DSG and driveshafts aren't friendly priced so I'd rather not replace them to find out they weren't ever the issue  HELP HELP HELP!

[Nasir]

I'd double check the wheel balancing first. Swap the tyres front to back as you said. This is the cheapest and easiest way to eliminate an alloy/tyre issue. That would be your first port of call. My wheels were supposedly done whilst the tyres were being fitted, but they had to be redone again after they started wobbling violently. Redone again and it's all fine.

[andyR43]

My guess would be a knackered cv joint.

[Ricky123]

does it do it at a set speed regardless of what gear your in?

Also once it starts at said speed does it continue regardless of mph or does it smoothen out after a certain speed? If it continues then does it get worse or stay roughly the same?

Does it happen purely under acceleration and if so then do you get any change when you lift of or put the car into neutral?



I've had a similar issue to what you describe on a focus ST i previously owned and it turned out to be the driveshafts at fault, this was also quite low and lowering a car can put more strain on the CV joints.

my sisters a3 had a similar issue that no one could diagnose, I replaced her clutch and flywheel and it was resolved. The flywheel was nackered causing the car to shake at motorway speed, it was more violent in 6th gear than any other.
Not sure if that could be your problem as you have a DSG box.

If you have no luck with anything and end up having to try driveshafts then maybe cheaper to try and source some second hand shafts or just buy new inner and outer CV joints for your current ones.