Alternator Life
 

How long do they typically last in the diesels? My 190E ate them for breakfast - I was constantly changing the volt reg pack/brushes after I learned how. First 2 times I got new alternators.

I've been driving this rig for almost 220,000 miles (currently 306K miles) and still the same alternator! I check while driving and the volts coming back are 13.1-13.5! I do have a squeal and wondered if it might be a failing alternator although my indie says the pulley is moving nicely and doesn't seem to be the issue -the squeal did occur after they washed my engine to look for a possible coolant leak - nothing found.

thanks
1996 E300

The noise is probably a slipping belt.
With a diesel having such a large battery, the load on the alt is much more gentle & so maybe helps it to go longer.
At 600k to 700k miles the slip rings are generally gone down to the plastic.

I've had to replace the alternator on all of our MB's at least once, except for my 300E. So far we've driven it about 21k with 0 issues from the electrical system.

When they build a car they want they are hoping everything on the Car; including the Alternator is going to last past the Warranty.

The comment about the Battery is well placed. You need to have a Battery of the correct capacity or better.