GLA200d 4Matic judder/shudder

[Liam94]

Have a 2018 Mercedes GLA200d 4Matic auto, car drives perfectly as it is should aside from a judder/shudder from between 15-20MPH. This manifests itself in comfort/sport/eco mode, manual or auto mode and happens in all gears 1-4 that you can manage 20mph in. It doesn't feel like engine or gearbox, I was wondering if it could've been the gearbox fluid as this was due, but it's been done and still persists. No warning lights. The diff was replaced in 2020 by Mercedes. It does not do this at any other speed at all.

The car has recently been serviced, had a new battery, new gearbox oil & filter and still the issue is present. The only thing I have noted is the rear continental tyres are odd, one is a premium contact the other an ultracontact. I have four new Goodyears coming tomorrow which are due to be fitted this week to see if this could cause the issue, but I'm out of ideas. Anyone ever had anything similar?

 

[onefortheroad]

Is it the front tyres banging on full lock ??

 

[Srdl]

I’m not an expert in any of the mechanical bits but it is speed dependent not engine revs so something in the drivetrain after the gearbox? If the tyres doesn’t sort it, check the drive shaft and rear diff? The dealer recently noted some wear on my drive shaft couplings and I understand that can start to cause vibration if it degrades further.

 

[Liam94]

I haven’t noticed it banging on full lock. This is the thing it’s only between 15-20 mph, all other speeds it never happens. Sitting there and revving the vehicle to the same RPM it never does it.

 

[Liam94]

I haven’t noticed it banging on full lock. This is the thing it’s only between 15-20 mph, all other speeds it never happens. Sitting there and revving the vehicle to the same RPM it never does it.

Definitely no noise on full lock, went round in a car park to test this and nothing. Tyres arrived today and have been changed. It feels slightly better but it's still present. Going to book it in for a diff oil change and see how we go. Fingers crossed. The diff was replaced in 2020 by Mercedes, but the oil hasn't been changed since and it's done a fair few miles since then. Hoping this cures the issue.

 

[Srdl]

Definitely no noise on full lock, went round in a car park to test this and nothing. Tyres arrived today and have been changed. It feels slightly better but it's still present. Going to book it in for a diff oil change and see how we go. Fingers crossed. The diff was replaced in 2020 by Mercedes, but the oil hasn't been changed since and it's done a fair few miles since then. Hoping this cures the issue.

Get them to look at the driveshaft at the same time,