A bit of advice and your experience please.
I have just had new subframe and diff bushes fitted by the indy in London I've used the last 20 years. They took it out to test after fitting and all seemed fine. I collected the car and ran around London for an hour or so on business visits and then headed back to Wales. All fine until about 40 miles out of London on the M4 when I had a quite bad vibration from the back I think but it affected the whole car. It seemed odd - not brakes, I was doing around 70 in the traffic. Vibration lasted about 1-2 minutes and then went away. I assumed a dodgy piece of tarmac but wasn't totally convinced. Rest of journey - 180 miles no problem.
Next day same thing happens at about 50 on a B road. Also heavy vibration from brakes as well this time. Seemed to be from the back but not sure. Again it only lasted a few seconds. This is a road I drive often so I'm sure it is not the road surface.
New bushes are Powerflex yellow for subframe and purple for the diff. Dampers, top mounts, brake disks, pads, Roll bars and rubbers, Lollypops, wishbones etc. all less than a year old. No sign of sticking callipers. No cracks / buckles on wheels, tyres Conti runflats, again about a year old. Diff turned smoothly by hand from the disk and the prop .
I have been underneath and spanner checked everything I can reach having removed the alloy splash shield. Currently awaiting delivery of an E12 long torx socket to try the driveshaft / prop bolts but they also seemed tight with a short socket half on. (couldn't get it on straight due to the drive shaft rubber boots blocking access)
Now somewhat confused as I can't see anything wrong. I'm hoping someone may have come across this before. The indy is happy to have the car back and sort it but I am loath to drive 220 miles without at least some idea of the cause.
I have also considered a damaged Giubo and out of balance drive shafts / prop but can't see how they would be intermittent.
Any thoughts gratefully received !
I have just had new subframe and diff bushes fitted by the indy in London I've used the last 20 years. They took it out to test after fitting and all seemed fine. I collected the car and ran around London for an hour or so on business visits and then headed back to Wales. All fine until about 40 miles out of London on the M4 when I had a quite bad vibration from the back I think but it affected the whole car. It seemed odd - not brakes, I was doing around 70 in the traffic. Vibration lasted about 1-2 minutes and then went away. I assumed a dodgy piece of tarmac but wasn't totally convinced. Rest of journey - 180 miles no problem.
Next day same thing happens at about 50 on a B road. Also heavy vibration from brakes as well this time. Seemed to be from the back but not sure. Again it only lasted a few seconds. This is a road I drive often so I'm sure it is not the road surface.
New bushes are Powerflex yellow for subframe and purple for the diff. Dampers, top mounts, brake disks, pads, Roll bars and rubbers, Lollypops, wishbones etc. all less than a year old. No sign of sticking callipers. No cracks / buckles on wheels, tyres Conti runflats, again about a year old. Diff turned smoothly by hand from the disk and the prop .
I have been underneath and spanner checked everything I can reach having removed the alloy splash shield. Currently awaiting delivery of an E12 long torx socket to try the driveshaft / prop bolts but they also seemed tight with a short socket half on. (couldn't get it on straight due to the drive shaft rubber boots blocking access)
Now somewhat confused as I can't see anything wrong. I'm hoping someone may have come across this before. The indy is happy to have the car back and sort it but I am loath to drive 220 miles without at least some idea of the cause.
I have also considered a damaged Giubo and out of balance drive shafts / prop but can't see how they would be intermittent.
Any thoughts gratefully received !