Nope, just undo the wires, the two rear allen bolts, and the bolts on the bracket at the front of it, and out it will come, far easier to loosen the bolts and wires underneath, and then lift it out from above. You'll need to remove the heat shield, battery, battery tray, and air cleaner. It took me a long time to figure all this out, otherwise it'd have only taken a few hours.
Its way easier on a W126....I replaced the one on my dad's car in about 2 hours start to finish, all from underneath. Easy. W126 rocks!
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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)