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replacing alternator, 85 380 SL

2K views 6 replies 6 participants last post by  oceanfront 
#1 ·
Hello, my 85, 380 SL has 115,000. I was thinking of rebuilding my alternator as a preventative measure. The car is running fine, but not sure if with the miles on the car, it would be a good Idea to take care of it now?

Now, the problem is that I'm not too sure about the process. My first guess is to disconnect the battery, and then disconnect the wires from the alternator.

looking at the engine bay from the front I can see that there are two bolts holding the alternator, one of the bolts must the the tensioner, my guess is that it's the one on the right side looking at engine from front, and the second, bolt, seems to be holding the bracket. that has a star shape washer that holds the alternator in that position.

Does the Alternator come out from the top? Are there other bolts, at the back?
there is very little room to work from. Do I have to raise the car?

IF anyone has done this before would appreciate your impute?
I've done some searches, but have found nothing. I have the MB, CD, but that does not cover how to take off the Alternator. Disappointing!

Thanks for any help!
D.
 
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#2 ·
My old man said I should never take out the alternator and that all you have to do is change out the brushes on the back of it. I guess he got it out and couldn't get it back in. Try just changing the brushes. Good luck!
 
#3 · (Edited)
oceanfront,
daryn is spot on. The brushes he's referring to is actually the voltage regulator/brushes assembly, about $30 from any of the online parts guys. These absolutely do go bad/wear down, you won't get a warning and your car will simply just die one day while you're driving down the highway. Easy changeout and a decent proactive thing to do.

You may want to check out this site for the how to steps in replacing the most vulnerable part of the alternator, the integrated voltage regulator. FYI...

BEST Run Insurance (Voltage Regulator) | MercedesSource.com

Bob
 
#4 ·
Um, not disputing any wisdom about replacing brushes or voltage regulators, but...

My alternator died (the first big trip out of town) and I replaced it with the tools I had with me in about 15 minutes while sitting in a parking lot. Now I'd like to think I'm some kind of uber-mechanic, but it just wouldn't be true.

Release the tension bolt, remove the pivot bolt, take off the belt, pop off the electrical connectors and the thing practically falls out. Reverse to put it back in. Hardest part of the job was hiking both old and new alternators back into the auto parts store so they could use the impact wrench to swap the fan and pulley from old to new. It really isn't any kind of a big deal.
 
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