replacing alternator 300ce
 

hey guys,i was wondering if anyone knows the size of the bolt on the alternator pivot 1989 300ce 3.0l,i think the tensioner bolt rod is 12 mm,please correct me if im wrong. i just put a bosch reman in 5 months ago,and i had to do it without loosening the serp belt,needless to say it was a 3.5 hour job and very sore arms later,thought id get much more time out of it,the current alt is putting out a high spike of 13.0 volts then dropping to 11.5 anyone think there is a possibility of a defective volt regulator?,THANKS!!

Yes that sounds like a bad voltage regulator. You should be able to replace it without removing the alternator.