ML 270 fan belt idler, one to watch.

[BIGjoe]

The bearing went on one of the fan belt idler's, not an uncommon occurence, except that it pushed the belt off course before the pully left the spigot, causing the belt to momentarily rub against the plastic fuel pipes routed between the end of the head and the belt, just long enough for it to cut a little nick in it , resulting in sprayed fuel just about everywhere , not nice

 

[timskemp]

Had mine replaced and also the water pump - went quite noticeably noisy. Was almost impossible to turn by hand when removed!