c70 low speed driveline vibration

[jonnyboy54321]

Hi chaps.
New here - looking forward to contributing.
Bought my wife a low mileage freshly mot'd c70 auto, a 2.4 SE Lux, 2008.
It's got a bit of a driveline vibration under acceleration between 15-35mph, quite subtle but there, more noticeable under harder acceleration.
If anything it feels like shimmying through the car ie no feedback through steering and the likes - you kindof feel it though the floorpan/your feet, and through the seat on your bum! Definitely appears to be more front n/s based.
As part of my working my way through the car - it's had a new wishbone on the nearside as a bush was shot, it's had replacement decent tyres and the wheels were checked for buckling.
It's a bit of a weird one as it seems to go at speed, in all other aspects the car seems fine. I'm fairly sure it isn't a characteristic of the car although its the only one I have driven to be fair.
Anyone got any ideas?
Appreciated.

[dme123]

What is the engine speed at those RPM? The I5 engine has lots of odd vibrations around 1800 - 2200RPM, more noticeable at low speed because there are less vibrations from the road, wind etc.

Do you feel it if you slowly build revs in neutral at a standstill?

[jonnyboy54321]

I need to check engine speed. Will do that tomorrow.
Can't particularly feel anything when revving the engine at a standstill.
I do know there is very minor play in the nsf inner cv but it is very very minor.
Like i said, it feels like a shimmy through the car. Hard to describe.
It seems, and I stress seems, a bit less obvious since we did the wishbone (the large big bush was shocking).
Only other thing of note is that I do know the car had been potholed as it came with a cracked alloy in the boot but I do not know which of the four wheels it was.
I will be having it 4 wheel aligned next week - had been waiting till after the wishbone.

[Austin160]

Vibration felt through the seat can be due to rear wheel balance/tyre issues.
If it were mine, as would have each wheel removed and the tyres carefully checked ( potholed) - particularly the sidewalls - then if they are confirmed to be OK then have them rebalanced. Might also be worth putting fronts on back and vice versa.

[jonnyboy54321]

Thanks Austin

Just for clarity, one wheel was slightly pothole buckled, all tyres changed, wheels have been moved about yet fault remains consistent.

[jonnyboy54321]

So to further this - I drove Madams car again today.
It happens between about 15-35mph, low engine revs ie generally under 2500 but happens whatever gear it's in - I switched to manual, held it in 1st/2nd etc, didn't make any difference.

[jonnyboy54321]

Right.
I will further this thread when:-
I've resolved the osf wishbone which is also ****ed, replaced the scrubbed back tyre on the back, sorted out at least two wheels including the one I've just found a crappy weld in.

Further woes though are the exhaust which will have a nice thread of its own

[alexstanleyv50]

You'll soon find that although things like wheel hubs have no play, tyres are aligned and balance and bushes look good they are actually totally fubar. I had been chasing a vibration under acceleration (sounds very similar to yours) for about 3 months.

Turns out there was a slightly buckled wheel and a knackered hub which were replaced only to find the vibration was still there although not as bad.

A laser check on the tyres showed the fronts to be totally miss-shaped. Two new tyres and all good.

Only theory we could come up with is the power (and the breaking/turning) that goes through the fronts just ruins cheap tyres... Pirelli's it is then... and I'm finally no longer chasing a vibration... but it has brought my attention to a very annoying rattle!!!!!

[jonnyboy54321]

Replaced both hubs on the car as they were actually fubar.
Seemed better for a while but is still there although milder.
Tyres wheels all swapped around and no difference.
Need to replace a gearbox mounting as next step as lots of play - will report back.

[zapcity1]

Been having similar problems for a while. Slow speed ride very poor and a noticable vibration especially through seat and steering.

Knew the front wheels were egg shaped (picked up at last MOT), but had some fun sourcing some new wheels.

C70 D5 auto running 18" Mirzam alloys, which even with some decent discounts, work out at over £1000/pair.

Managed to get one brand new wheel from a Volvo dealer in Germany (on ebay) for £260 delivered which is a great price. Unfortunately they now only have sets of 4 (still only £1070 per set delivered to the UK), so trying to get them to sell me just one!

Shop is: - la_linea_eu
http://stores.ebay.co.uk/llautoshop?...p2047675.l2563

Selling all genuine parts but prices seem very compettitive.

Just to cap it all, I also knew something had changed with the car handling. Normally a C70 is rock solid in corners. Not agile, but well planted and predictable. Putting the car up on the ramps soon found the problem. 2x broken front springs.

So all in the last year I've had new Bilstein B4s all round, new front springs and top mounts, driveshafts, new tyres and one new front wheel. Car at 120K now, so not unexpected.

Handling and ride now so much better and I think a 2nd new front wheel will get it about as good as I can. Much more comfortable to drive now.

This is the wheel removed, so you can see the flat spot at the bottom. Very noticable effect when driving!

[IMG][/IMG]