changing the alternator

[Rbeguelin]

Hi all,

I recently purchased a new Bosch alternator thru Pelican for my 1973 450SL. In the pictures the alternator looked the same as what I was replacing however when it arrived I realized there were differences.
The position of the bracket mount on the alternator is such that the three prong D+,D- and D plug is closer to the water pump, tucked in back of the alternator almost touching (3/4 of an inch) the valve cover.
On my old alternator the three prong plug was almost directly in front of the oil level tube. I was able to extend the wiring harness to be able to insert the three prong plug.
With this new position the B+ wire is almost exactly where the three prong plug was on the old alternator.
My question: Since these units are all rebuilt, is it possible that the pully side of the alternator with the mounting elbow and separate adjustment mount hole got twisted in a rebuild by a mistake. All the three bolts holding the alternator together are evenly spaced apart. I actually was going to try to shift the pully side of the alternator one bolt or 1/3 a complete turn. But decided against it till I hear back.
Thanks
Rob

[Frank Reiner]

Originally Posted by Rbeguelin

Hi all,

I recently purchased a new Bosch alternator thru Pelican for my 1973 450SL. In the pictures the alternator looked the same as what I was replacing however when it arrived I realized there were differences.
The position of the bracket mount on the alternator is such that the three prong D+,D- and D plug is closer to the water pump, tucked in back of the alternator almost touching (3/4 of an inch) the valve cover.
On my old alternator the three prong plug was almost directly in front of the oil level tube. I was able to extend the wiring harness to be able to insert the three prong plug.
With this new position the B+ wire is almost exactly where the three prong plug was on the old alternator.
My question: Since these units are all rebuilt, is it possible that the pully side of the alternator with the mounting elbow and separate adjustment mount hole got twisted in a rebuild by a mistake. All the three (or four) bolts holding the alternator together are evenly spaced apart. I actually was going to try to shift the pully side of the alternator one bolt or 1/3 a complete turn. But decided against it till I hear back.
Thanks
Rob

Actually, the front of the frame would be considered to be the fixed location component; the back section, with the plugs & terminals can, and is, clocked to the position appropriate for the installation. You can move yours as necessary. Remove the three (or four) through bolts, and rotate the back section without separating the sections.

[Rbeguelin]

thanks for the info Frank,
I was looking at the wrong end not the first time!
Rob

[Dmitry at Pelican Parts]

Hello - if anyone is still looking for info on replacing the alternator, check out the link below to our site's DIY tech article.

Mercedes-Benz R107 Alternator Replacement | 1972-1986 - 450SL, 380SL, 500SL, 560SL | Pelican Parts DIY Maintenance Article