Author Topic: 55 AMP ALTERNATOR  (Read 5384 times)

awolff280sl

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55 AMP ALTERNATOR
« on: January 29, 2008, 19:56:47 »
Does anyone know if either the Bosch alternator designated AL72X or AL74X is the bolt on 55 AMP "upgrade" for our 35 AMP alternators (designated AL64X). I thought the AL72X was the one, but when I put my original (iron) pulley on it, the alternator fan scrapes the housing. The attached image shows the AL72X on the left, and the alternator presently on my 280sl.  Should I look for a different alternator or a different pulley?

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Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo

jeffc280sl

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Re: 55 AMP ALTERNATOR
« Reply #1 on: January 31, 2008, 12:23:34 »
I replaced my AL64X with a AL74X and reused the pully fan.  I did need a new plug to make the elctrical connections.

Jeff C.
1970 280SL 4-speed

waqas

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Re: 55 AMP ALTERNATOR
« Reply #2 on: January 31, 2008, 12:36:50 »
I did the same, and as these were used on sedans of the era (early 70s), I found the alternator together with the plastic/bakelite connector at a dismantler. (I suppose you could also get the connector new from the dealer or other supplier-- e.g. look for the corresponding early 70's 280se 108 part).

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

al_lieffring

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Re: 55 AMP ALTERNATOR
« Reply #3 on: January 31, 2008, 12:56:04 »
In the photo it looks like you have the cast aluminum fan.
You may have to change it over to the later style stamped steel fan. I believe these were made for the 55anmp alternator.


Al Lieffring
66 230SL
« Last Edit: January 31, 2008, 12:57:06 by al_lieffring »

awolff280sl

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Re: 55 AMP ALTERNATOR
« Reply #4 on: January 31, 2008, 18:24:52 »
It seems Al's suggestion to use the updated pulley makes it work.
Since some members have reported no problem with their original pulleys on the 55amp, I wonder if there is more than one alternator pulley type, perhaps due to aftermarket A/C.
Thank you!
Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo