About 2 months ago, I began to experience really intermittent judder under acceleration in my 2015 120d xdrive - just about to hit 70,000 miles. Been faultless until now.
The tyre setup at the time was as below - all runflats and all BMW * marked.
Front
Nearside: Bridgestone Turanza 225/40 R18Y (92)
Offside: Bridgestone Potenza 225/40 R18Y (92)
Rear
Nearside: Bridgestone Potenza 245/35 R18Y (88)
Offside: Bridgestone Potenza 245/35 R18Y (88)
Due to a pothole hit several months prior, the tread depths varied across both axles. I took the car into a reliable local dealer who said I should ensure all tyre brands + tread depths should be matching as otherwise I could cause premature wear to the transfer box, they also told me there are zero fault codes. I’d also read a fair few posts about odd tyres potentially causing transfer case issues. I decided to replace the offside front and rear + nearside front tyres to ensure all tread depths and tyre brands were identical. I’m now running Potenzas all round but the issue still remains.
Playing about with tyre pressures seems to alleviate the problems somewhat (especially when I set the fronts to their maximum load pressure of 2.4bar and the rears at 3.0bar) but the judder is still really quite noticeable - mostly at speeds of 50-80MPH at moderate to heavy throttle use.
The car has been into a BMW specialist near my workplace who said it was potentially the post-cat O2 sensor, they replaced this but the issue still remains. All wheels/tyres are balanced and 4-wheel tracking has been done. The best way I can describe the feeling is almost like a clutch slip/aquaplane/wheelspin, intermittently under acceleration. Still no dash lights or fault codes + under most normal conditions and soft acceleration the car is perfectly fine to drive.
I’ve come to the conclusion that the car either needs a transfer box oil change or a full transfer box replacement, the latter in understand to be £1000s. I’m no expert and don’t know whether there is any permanent damage, I’d appreciate any advice/any other owners who have had similar experiences. I’m not far away from ringing a different local specialist and asking for a full diagnosis to see what they’d find and quote.
Thanks.
The tyre setup at the time was as below - all runflats and all BMW * marked.
Front
Nearside: Bridgestone Turanza 225/40 R18Y (92)
Offside: Bridgestone Potenza 225/40 R18Y (92)
Rear
Nearside: Bridgestone Potenza 245/35 R18Y (88)
Offside: Bridgestone Potenza 245/35 R18Y (88)
Due to a pothole hit several months prior, the tread depths varied across both axles. I took the car into a reliable local dealer who said I should ensure all tyre brands + tread depths should be matching as otherwise I could cause premature wear to the transfer box, they also told me there are zero fault codes. I’d also read a fair few posts about odd tyres potentially causing transfer case issues. I decided to replace the offside front and rear + nearside front tyres to ensure all tread depths and tyre brands were identical. I’m now running Potenzas all round but the issue still remains.
Playing about with tyre pressures seems to alleviate the problems somewhat (especially when I set the fronts to their maximum load pressure of 2.4bar and the rears at 3.0bar) but the judder is still really quite noticeable - mostly at speeds of 50-80MPH at moderate to heavy throttle use.
The car has been into a BMW specialist near my workplace who said it was potentially the post-cat O2 sensor, they replaced this but the issue still remains. All wheels/tyres are balanced and 4-wheel tracking has been done. The best way I can describe the feeling is almost like a clutch slip/aquaplane/wheelspin, intermittently under acceleration. Still no dash lights or fault codes + under most normal conditions and soft acceleration the car is perfectly fine to drive.
I’ve come to the conclusion that the car either needs a transfer box oil change or a full transfer box replacement, the latter in understand to be £1000s. I’m no expert and don’t know whether there is any permanent damage, I’d appreciate any advice/any other owners who have had similar experiences. I’m not far away from ringing a different local specialist and asking for a full diagnosis to see what they’d find and quote.
Thanks.
