During December we received ten separate reports of Right Hand Drive Mercedes-Benz GLC and GLC Coupes making an “awful noise” when significant lock is applied.
The standard tyre sizes for the AMG GLC 43 4MATIC Coupe are 235/55R19 front and 255/50/R19 rear. To overcome juddering and jumping of the tyres, Mercedes Benz tells customers: “It is something which can be felt only at very low speeds and when a certain percentage of wheel lock is engaged for turning. This is demonstratively more evident in colder temperatures due to the changes in the tyre rubber elasticity. As per the Mercedes-Benz Digital Handbook for your car, we would always recommend the use of winter tyres for temperatures, which fall below approximately +7 degrees. The recommendation given to improve this characteristic would be to change the tyres on your vehicle to suitable tyres for the winter period.” Honest John reported on honestjohn.co.uk
This has infuriated owners. The problem not only occurs on the high performance GLC 43 with staggered tyres, it occurs on all GLC and GLC Coupes. Particularly since over this winter the ambient temperatures has rarely fallen below 7 degrees and the problem occurs at all temperatures.
One owner who regularly suffered the problem on a roundabout in Australia (where the temperature never falls below 8 degrees), eventually persuaded Mercedes-Benz Australia to put his car through a full four way laser alignment, where all four wheels were found to be out.
This almost entirely cured the problem and the owner has driven a further 12,000 kilometres with “crabbing now minor on the same roundabout.”
Mercedes-Benz UK refuses to re-align UK customer GLC and GLC Coupe models and simply tells its customers to buy a new set of winter tyres.