theSHARK320

My 2008 ml320 is making a bearing noise. At first I thought it was a left front wheel bearing because the sound would go away when I abruptly steered to the left and shifted the vehicles weight. Then I noticed that the very slightest bit of pressure to steer left caused the sound to go away.

Could this be something other than a wheel bearing? Perhaps steering related, or tranfer case bearing. I might get an alignment and see if that helps.

It has lower miles for the year, around 70,000m.



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C230 Sport Coup

Typically it's the front differential crappy Polish Bearings.
Check out benzexpert.com
They have diff and transfer case parts.

chassis

Try driving around 60mph - 65mph steady speed with no cruise control (foot on the gas pedal). Note any bearing or gear sound. Then let off the gas pedal, and listen for a change in any sound. Do this repeatedly until you confirm or deny the sound is related to drivetrain torque. If the sound comes and goes with throttle at steady speed, it's somewhere in the drivetrain. Sounds like C230's suggestion is a good one, if the test above points you in this direction.

theSHARK320

Thanks for the info and suggestions.

I will try that road test. I also plan on putting the vehicle on a hoist and having a listen underneath of the individual components with stethoscope.

Will update with what I find.

2008 ML 320 CDI

Don't overlook the tyres! I once replaced a front wheel bearing 3 times in short succession. It's a long story but in the end it was discovered that the first bearing replacement was indeed necessary because the old bearing race was pitted but the subsequent bearing replacements were not necessary because as it turned out to be tyre noise from tyres that appeared to be perfect!