T27 - vibration above 40mph

[Peter Wilks]

Just replaced all 4 tyres to a different brand an now have a vibration through the car above 40mph quite bad around 70mph but can be intermittent on the motorway in its intensity, I've been to my local mechanic who has checked the balancing on tyres, they are all good. one thing we did notice was the front drivers side shock extended fine then made a small pop/clunk for the last 5/10mm of its travel to full extension, I'm guessing it shouldn't do this but before I spend the money to replace them would this indicate a problem that could be causing the vibration?

I've been round and made sure the caliper slide pins are all free to eliminate a stuck caliper.

 

 

[alan333]

Swap the tyres front to back and see if the symptoms change.

[Heidfirst]

these aren't by any chance unidirectional tyres & they have fitted 1 or more incorrectly?

[Peter Wilks]

Tyres are all on the correct way, when I install the new caliper pins I will swap the tyres see if that helps.

[Peter Wilks]

Swapped the tyres around, no change. I did notice some oil staon on the side of the drivers side rear shock and i could move the wheel up and down easily, this would tie in in poor handling around LH bends so i'll look to change bothe rear shocks, this might cure the vibration if the shock is shot. anybody know how you get to the top bolt to remove the rear shock?

[m456an]

Wheel alignment?

[Peter Wilks]

Changed the rear shocks rides smoother but the vibration hasn't gone. wheel alignment is spot on (had it checked when new tyres fitted). going to fit my winter wheels which I know are spot on balancing and not out of shape to the front then back to see if it changes the symptoms, could be a slightly out of shape rim?

[Peter Wilks]

Swapped to my winter wheels and the vibration has gone! when I spin the wheels and hold something near to them for reference the tyre moves 5-8mm  so its either the tyre or the rim causing the problem. Is it worth getting them straightened or just get another couple of alloys off eBay?

[alan333]

Hold your 'something' against the edge of the wheel instead of the tyre, if it runs even then the problem is with your tyres.

[Peter Wilks]

Had all the tyres and wheels checked and rebalanced, one wheel was out of balance. tried swapping onto my winter wheels on the front and back with no change. definitely feels like its from the front, can feel almost a pulsing through the wheel from 20-30mph even on  recently surfaced which I now are smooth from driving in other vehicles. the frequency doesn't change but the intensity of it does. any ideas? front shocks? wishbone bushes? 

[Willss]

I had vibration (through a Ford) when going above 50mph and sometimes when braking at the same time as turning.  Tried LOADS  of things but when the front bushes were replaced during a service the problem went - no one had suggested that could be the issue so it was just good fortune that the mechanic saw that they were splitting (apparently not that badly) and suggested replacing.  Was quite a subtle split when he showed them to me but obviously enough.

[Peter Wilks]

Still haven't got to the bottom of this, if anything the issue is getting worse, I can now feel a vibration through the steering wheel from 20mph all the way up to 70/80 with not much change in the intensity or frequency, possibly slightly more noticeable at higher speeds, braking, accelerating and steering don't seem to affect it. I've tried rotating the tyres and tried different wheels which don't change the symptoms, I've also put new discs and pads on  with no change. Had a couple of mechanics check it over and can't see anything obvious, only noticeable thing is the slight clunk from the front right shock when the car is lifted up. 

[alan333]

On 07/09/2017 at 3:48 PM, Peter Wilks said:

Swapped to my winter wheels and the vibration has gone! 

 

6 minutes ago, Peter Wilks said:

Still haven't got to the bottom of this, if anything the issue is getting worse, 

Is the problem cured with the winter wheels?

[Peter Wilks]

No, it still feels the same.