ML280 rumbling noise

[EspritSE]

Hello all,

There is a rumbling noise on my daughter's 2006 ML280 which I think is coming from the front nearside. It is most apparent at 20 - 35 mph.

The gearbox has been leaking oil from one of the cooler pipes so I feared the worst. I have bought new cooler pipe seals, drained and refilled the transmission as per the WIS procedure (run up to 90C then down to 45C etc). The old oil was a brown/red colour. The magnets had a small covering of a fine grey material, there was no other debris in the oil pan. I opened the oil filter with tin snips and there was no shards or debris in there. There were no error codes on the diagnostics. The oil change made no difference to the noise.

After changing the transmission oil on the test run I put the car in to neutral whilst going down hill and the noise was unchanged. I hope this rules out the gearbox?

I am starting to think/hope the oil leak is a red herring and it may something be else, wheel bearing etc?

Any advice on possible causes or checks I could do would be appreciated.

 

[Dodipops]

Wheel bearing is common, and is often in y experience front left.

 

[EspritSE]

Wheel bearing is common, and is often in y experience front left.

Wow Thanks,

Just what I found.

After my initial post I went out to the garage jacked the front of the car, took both front wheels and calipers off. Spun both discs and heard a slight rumbling on the front left. The bearings are quieter with no load on them and more difficult to diagnose.

Ordered a FAG bearing kit from ebay, hopefully will arrive today.

 

[EspritSE]

Front left wheel bearing cured it.

With no load on the wheels the noisy bearing was a subtle noise and only noticable when comparing to the wheel on other side.

Bigger job than I thought, took ages to release the rusted in place circlip from the steering knuckle and pressing the bearing out took a lot of force (I have access to a hydraulic press).