I am trying to find out why there is a vibration coming from under my 2000 ML430. The vibration only happens typically at speeds of 50+ and only happens when i let up off the gas and coast for a few seconds. If i apple acceleration again or wait a few seconds the vibration stops. I also have had the BAS/ESP/ABS lights on. Any help would be great. Also is there a way to test an ABS module to see if it is bad or not?

 

probably your driveshaft center support bearing. could be I should say. trans mount maybe, motor mounts are common on the ML430s, trans mount too maybe

 

Check the front propshaft for the kind of vibration you describe.........., the large 'double' joint arrangement (you will see what i mean) at the end nearest to the transfer case are known to fail, check for any 'up and down' play in the joint, there shouldnt be any. No repair is available for this joint meaning a whole complete propshaft is required. The vibration would come from nearer the front/left of the car for this failure.

Also, (as mentioned) the main propshaft centre support bearing could also cause a vibration emanating from the 'centre' of the car.

Finally, check ALL propshaft UJ's.

 

I appreciate the help. I believe that it is coming from the front the strongest. It also is more noticeable at times then not. I am wondering if it has something to do with the front drive shaft. My front tires are also pretty worn out because i just changed the rear so i dont know it it has anything to do with the AWD or not. It did have the vibration, however, when i bought it with all four tires worn. Also the previous owner did change the motor mounts. I will check the joints. What are the odds the transmission supports cause the vibration? Thanks.

 

With permanent awd vehicles (as the ML is) it is important for all the tyres to be equally worn, new tyres on one axle and worn tyres on the other will put strain on the transfer case.

Re the vibration...........I would say to check the points i previously mentioned first, i suspect it will be the front prop joint thats gone, sometimes, you will occasionally hear a soft 'rattle' sound when the joint fails.