Uneven rear tyre wear on my V90 T8. Help me narrow down the cause.
V90 T8 2020
Michelin Pilot Sport 4 S I had all the tyres fitted at the same time.
I drive a Volvo V90 T8 estate. I put a fresh set of tyres on all four corners at the same time. I just checked the tread depths and my nearside rear passenger tyre is down to about 2.5mm. The offside rear driver side is still sitting at 3.3mm.
I had new rear brake pads fitted about a month ago. To rule out a seized caliper dragging the wheel, I took the car for a drive today and measured the heat from each rear brake disc with a laser gun. Both sides were almost exactly the same temperature.
Here are the three main culprits I am looking at.
Misalignment from an impact. A heavy kerb strike or pothole can throw out the toe or camber geometry on that wheel alone. This causes it to effectively drag down the road. You verify this by checking the tread across the width of the tyre. If one specific edge is noticeably more worn than the centre, the alignment is out. My wear is relatively flat across the whole 2.5mm width.
Sticking brake caliper. A bound caliper creates constant friction. The wheel is always slightly dragging, which accelerates tyre wear. You verify this with a 15-minute drive and checking if the wheel radiates significantly more heat. My laser test showed normal temperatures today. I am wondering if the caliper was sticking and eating the tyre before the new pads went in last month.
Worn suspension component. These cars use complex multi-link rear suspension systems. A failing trailing arm bush or weak shock absorber allows the wheel to shift out of alignment under load. I plan to drive with the radio off and listen for a dull knock or squeak from that specific corner when going over speed bumps or rough tarmac.
Has anyone dealt with this much uneven wear on a heavy hybrid estate? I would appreciate any advice on what to check next before I just throw a new tyre at it.