Forgive the thread resurection, but I’ trying to work out what might be causing a light vibration, noticeable at motorway speeds. Car is a 2021 MY P525 which I’ve had a month. Its an LRAU car, so have been in touch with the dealer, which is 90 miles away, and I’m waiting to hear from them.

I’m noticing the vibration, because my old SDV8 didn’t behave in this way in 6 years ownership. That car had 22” turbines and it ran on Continental Cross Contact tyres. The new car has 22” too, but shod with Pirelli Scorpions.

My guess is its related to wheel balancing, so I’m intrigued to know what a ‘road force balance’ is, so I could make further enquiries with the dealer.

Thanks.

Andy.

Road force balancing differs to traditional spin balancing in that the machine used has a big roller which is pressed against the spinning wheel and tyre assembly thus emulating forces applied to the tyre when travelling down a road.

The system is then able to work out the high and low points of the wheel and tyre combination and direct the operator to reposition the tyre to its optimal mounting point on the wheel.

The assembly is then spun again and weight applied where required in order to achieve the lowest possible 'road force'

At least that's roughly how it was explained to me, I've used the service on both my previous Bentley and previous L405.

It worked wonders on the Bentley and was able to resolve a high speed shake that traditional balancing couldn't help.

Update.

The supplying dealer advised me to take the car to a my local LR dealer to have the vibration issue identified under warranty. Local dealer, who I have used for years, said its not a warranty job, so I’d have to pay for their time - fair enough, they didn’t sell me the car.

They took the car in and found that two new tyres had been fitted but were not on the same axle, so they swapped them round. Also noticed two wheels had buckles on the inner rim, which didn’t look recent - and I’d certainly remember if I’d hit a pothole or kerb hard enough to buckle a wheel.

I reported this to the supplying dealer, along with photos and they have said they’ll look into it. There is still a slight vibration, so logically, caused by the buckles, but the tyres all look true to the eye. I’m hoping the supplying dealer will sort out the repair and all will be good.

One thing which does occur to me though. All my FFRRs and previous RRSs were diesels, could it simply be that petrol V8s create more vibration through the body shell? I’m not experiencing juddering, just a slight resonance and only noticeable because I didn’t experience it in previous cars. My other car, a petrol Mini JCW does have a tendency to slight vibration, especially when cruising, but I’d always put that down to a combination of rock hard suspension and runflat tyres.

If anything the 5.0SC is smoother than the SDV8 so should not vibrate, mine hasn't done so. Two buckled wheels (even allowing for the greater vulnerability of the 22s) suggests the car has been thumped about. An impact that is hard enough to buckle a wheel would be apt to damage a tyre too. If you have noise reducing foam in the tyres this can come loose and cause imbalance, with adverse effects on running smoothness.

405s seem prone to wearing out suspension and ARC bushes so you might like to get those checked as well as the wheels and tyres, and also steering/suspension components in case the impacts have caused problems there too.

LR say one is not to rotate tyres around the car, doing so can cause vibration due to the wear patterns being unsuited to the new position, admittedly more so in blockier tyres such as Goodyear Duratracs. They also recommend changing tyres once they get to six years old, I did that this year, even though the tyres were not worn out and found the car felt much better for it, so once you have sound wheels that might be worth considering too. Only Range Rovers since 1988

Thanks, that’s useful feedback. The local dealer checked the suspension and said all was fine - and I trust them to be straight with me.

I replaced bushes and control arms on my SDV8 and also replaced 6 y/o tyres at the same time and it made a huge difference to that car. Maybe because I’d done that in the year before selling it and getting the current car has made me more aware if something is out slightly?

I’ll wait until the wheels are repaired - no idea if the tyres have noise reducing foam, but something I’ll ask about when the repairs are done. Note your comment about the impact causing the buckle to damage the tyres, maybe why there are two new tyres!

At the moment this issue taking the edge off the enjoyment of what is otherwise a great car.

Another update.

The supplying dealer took the car back and had the two buckeld wheels repaired. No quibbles, keen to resolve the issues and make sure I was happy. Got the car back yesterday and all seems fine, no noticeable vibrations and I spent about 6 hours driving yesterday.

I’m pleased with the outcome, especially the way the dealer dealt with the problems; they are part of a large group and I feared the worst, but they were really good to deal with. Well done Stratstone Milton Keynes, especially James Clough and Dominic Crowe.