XC60 Acceleration 'Thump' / Shudder / Vibration

[DarthVdr]

Hi,

I have a 2012 XC60 and just had brand new tyres put on, since then I've noticed some sort of vibration when under load - mostly noticeable at slow speeds. I've taken it back to tyre place and they confirm alignment and balance is fine - which I tend to agree - and I suspect that the new tyre is providing more feedback to an existing problem somewhere either in the drive shaft of suspension.

I took it to a gearbox specialist who took it for a quick drive - he thinks it possibly may be a torque converter issue between 2/3. The car has done 70,000km and has never had the gearbox touched - but his opinion he says it should be changed/flushed etc quite commonly.

Am in Australia and he states that European cars tend to advise no maintenance required for life of vehicle, but he says that 'life' means within the warranty period.

Thoughts/ideas about this?

I'm taking it back so he can do a full scan/analysis - am hopeful a simple flush and service will fix the issue but open to other suggestions anyone may have.

Car has always been serviced and maintained by Volvo, always done city driving in good conditions.

cheers!!!

[Redsun351]

Have you checked to make sure the tyre's are actually the same size? (I never trust what a tyre fitter says!)

Is the tyre tread on the other axle very low?
I had a similar problem with a Nissan Skyline 4wd a few years ago when I changed the rears, the rolling radius change was enough to fool the sensors in to thinking there was wheel slip and it was kicking in and out of 4wd. I Put new fronts on to match and no problems.

[DarthVdr]

All 4 tyres are literally brand new - less than 100km on them and they are the correct size.

Am thinking it is more mechanical.