W124 Alternator upgrade
 

So, after having several problems with the current alternator's setup (noisy bearings, corroded connections, and 65A just isnt enough) I've decided to upgrade to a bigger unit.

I've had a good read of GSXR's thread about his 143 and 150A upgrades, but would like to ask a few questions about other Alternators. Firstly, so all Bosch alternators have the same mounting holes? I'm currently looking at a 130A model of a Saab 9-5 that looks to be of the same mount as the current setup (except it has an internal fan and a longer pulley), but will the holes line up?

Well well well, no replies. So, I've decided to find out for myself if this will work, and will share my results.

Today I received the alternator, cost £27 ish delivered, so a pretty good deal. From first impressions it appears to be in very good condition and looks like it will fit nicely. So far I have managed to get the pulley off the Saab alterantor, and have driven to go and buy new connectors to hook it off. I got the pulley off by wrapping an old serpentine belt around the pulley and then gripping this with mole grips, hopefully will work with the old alterantor too. Unlike GSXR I'm not going to upgrade the wiring since I havent got an extra loads, and instead am just going to snip off the old connector and crimp/solder on new ring terminals. That will all be followed up by shrink sleeve and then grease over the bare metal.

I'm off to start work now, will try and get some pictures and post them up here soon.

Update: Very big fail in that whilst trying to remove the pulley off the old alternator I managed to break the woodruff key rather than loosen the nut. Fortunately, the alternator doesnt generate enough torque to make the pulley slip on the car even under heavy electrical load, so until I can go to the dealer to get a new pulley for the new alternator the 55A beast is back on the car, and thankfully still works after all of that bashing and pulling.

Saab does seem to be a good source for alternators, as do later Mercedes gassers. I checked a later Volvo and found the mounting to be different.

Awesome! I will probably be doing this to my W124 eventually too.....

I wish I could have a 250D.....lucky europeans...

We call it: 300D 2.5 Turbo. Got them '90-'93.

I wish I could have a turbodiesel W124, theyre EXTREMELY rare over here! And you would never catch me going for a w210 to get a turbo, too many rust issues in this climate.

I installed a new 92Saab 9000 alternator in my 83 300CD and it fit with no problem. It needed to be coaxed in there however as it is a bit bigger than the original. I think it puts out 120amps or something like that. Works great. Powers the stereo with ease.

Yeah....but they have more of them available....and the coveted less powerful non-turbo version! :D ;)

Yeah, thats the problem. The most powerful diesel W124 we got (except the OM606 94/95 - but theyre expensive, more complicated, and seem to be a lot more rusty) is the N/A OM603 at 108hp. And that appears to have been only available in automatic. I could have got that, but instead I got the 2.5 5 speed which accelerates almost as fast (no horrible slushbox), gets much better economy, and is simpler.

So I could have fun exporting 603turbo engines to the UK?

Quite possibly. I dont have the skills, tools, or confidence (added to the fact I love revving the hell out of this N/A engine) to try a swap, but I'm sure there are a lot of people here who could and would.

Alternator Upgrade 250D
 

I got this from a recycler in Georgia. $50.00 USD.
It now has new bearings and a new voltage regulator.
'Came out of a 1996 SL 600.

Reprint of gsxr's chart below.Any 143 or 150 amp is a direct bolt on.

Well, its time to update this. I'm back at my parents house with access to a plethora of tools and random pieces, a lot of work will be commencing soon!

After my previous post, I purchased a new pulley from the dealer, but then discovered the unthreaded section of the shaft was too long on the new alternator, so with the nut back on the pulley could move back and forward about an inch, I needed to make a spacer. I managed this by grinding out the threads of an old rusty nut so that it fits over the alternator shaft. This then fit in between the top of the pulley flange and the nut. Heres some pics:

The new alternator without a pulley:
http://i57.photobucket.com/albums/g2...e/CIMG2581.jpg

Mercedes (left) and Saab (right) pulleys:
http://i57.photobucket.com/albums/g2...e/CIMG2582.jpg

Once again:
http://i57.photobucket.com/albums/g2...e/CIMG2583.jpg

The spacer:
http://i57.photobucket.com/albums/g2...e/CIMG2584.jpg

The spacer installed:
http://i57.photobucket.com/albums/g2...e/CIMG2585.jpg

The final product, with the nut torqued down:
http://i57.photobucket.com/albums/g2...e/CIMG2586.jpg

This should be going on the car soon, I have a small oil leak to sort out first, dont want my new alternator and pulley covered in oil before I start!!

Based on GSXR's notes, I replaced the alternator in my '89 300CE with the larger alternator. This was about seven years ago now. No problems at all. My mechanic was skeptical at first, but after showing him the thread, he went ahead with the conversion. One of the best "upgrades" I've done. Well worth it.