Motorway speed vibration

[ShivP]

Hi all,

I have an odd issue on my Mk4.5 Ford Mondeo. It is the 2.0TDCI 163PS with powershift box.

At 70-80mph, I have steering wheel wobble, and at all motorway speeds the car never "settles" - it has a jitter which doesn't upset the balance, but just never feels "smooth". At low speeds, absolutely fine.

Wheel balancing you say. I've had the wheels balanced 2-3 times (at the same garage) and no help.
He also suggested some new front suspension arms - had these replaced with delphi arms. This tightened the steering up nicely, but still the same issue.

The front and rear wheels have been swapped over - slight improvement but nothing really.
I had this issue with my previous tyres and the current ones - random mix match before and now 4x michelin PS4.
Car has just ticked over 75000 miles.
What could it be?

Thanks

 

[ShivP]

Agree - would be worth trying a different garage for one more go.

OK. I've booked into another garage to have a go tomorrow. Hopefully they can sort it

 

[ShivP]

Was going to say this - but noticed you have had this done three times, so assuming the garage is competent it would be unusual for them to fudge this over a few repeated attempts.

Just thinking out loud - has the car ever been involved in an accident? (Chassis, Axle, Driveshaft damage etc....).

No accidents I am aware of

 

[ShivP]

Keep to the speed limit and you won't have any problems

Still does is at 70 to be fair - OP was incorrect

 

[ShivP]

Yeah so I took it to ATS on Tuesday. It seems better, and the steering wheel vibration is now minimal but not quite fully gone still.

They said it was 20g off on a wheel which is not a huge amount, but some cars can be very sensitive etc etc.

It still has this "shimmy" on the motorway though. I don't know how to describe it, but most cars just settle but this still won't :/

 

[ShivP]

It can also be the way the front brake discs are mounted as these are sandwiched between the hub flange and wheel.. Sometimes the mating surfaces are not clean and dry before fitting. e.g. rust build-up, incorrect use of anti-seize on mating surfaces will make the wheel wobble slightly.
It could even be the hub flange is bent slightly if it has had a previous accident and only the wheel was replaced.

They did check the brakes, "spot on" is the term they used and my usual mechanic said nothing wrong there either

I'd bet on a worn suspension component. I had this a couple of years ago with one of mine, it just didnt feel "settled" which is the term which you are using too. Turned out to need a new control arm and it was great after that.

Had 2x new control arms fitted at the front. Potentially an old soft and over-squidgy damper?