Stupid Alternator Question
 

I have a '87 W124 300D with a bad alternator. I have a friend that's parting out a '82 300SD with a good alternator in it. Will the '82 alternator transfer to my '87 300D?

I have never tried it but I would not be surprised if it would. You should be able to look at it and tell whether it will fit or not.

Look on the back of the alternator and see if it has the brush arrangement that allows you to just change the brushes.

The '87 is likely higher output than the '82SD's will be......I would just find the correct one for your car.

Alternators rarely fail. The brushes on the voltage regulator do. Remove 2 screws that hold the regulator to the back of the alt. and pull it out. get new regulator and compare brush length. If 50% gone, replace regulator. Easy to do with the alternator on the car.

yes, the alt will fit in the hole for the 87... it's much lower amp output, but it will fit.
I'd pull the regulator out, and see what it does with a new one in there.

Yeah, I know it's a lower output alternator that what's in the '87. My problem is $$$, like a lot of us. The idea of checking out the regulator has much merit. I think that's what I'll have to do, since the parts are far less that the $131 for a rebuilt one.

Thanks for the input, guys!

Alternators are not specific to Diesels. In fact MB Diesels generally have lower alternator ratings than gasser counterparts. You're better off with a 300E alternator which is probably cheaper and easier to find than an SD alternator.

Sixto
87 300D

The SD alternator is free, so you can't beat the price. But since my alternator has over 150K on it, it might be wise to go ahead & replace it with a rebuild - bearing wear, etc.

87 will be a serpentine pulley, 82 a v-belt?