"Alternator" 115 Amp Bosch AL129X works in 123s! - Page 21 - PeachParts Mercedes-Benz Forum

fahrvergnugen · #**301** 02-03-2015, 11:41 AM

I appreciate the response, but have you done this swap? It doesn't bolt in as easily as the original. Some folks in this situation thread mentioned that as a way around the problem, but it hasn't worked so far.

JamesDean · #**302** 02-03-2015, 11:54 AM

Quote:

Originally Posted by fahrvergnugen

I appreciate the response, but have you done this swap? It doesn't bolt in as easily as the original. Some folks in this situation thread mentioned that as a way around the problem, but it hasn't worked so far.

I did it on my 300SD and 420SEL, neither had a problem mounting.

Maybe you could take some photos and post up so we can see what is going on?

fahrvergnugen · #**303** 02-03-2015, 03:14 PM

In the top photo, you can see that I can't line-up the bolt hole on the bottom with the belts on, and on the lower one, if you look closely, you will see that the top boss on the alt is hitting the top mount, which is also hitting the water outlet. I also can't get the top mount home so I can line-up the bolt holes for it.

sassparilla_kid · #**304** 02-03-2015, 03:17 PM

Why not just get a stock alternator rewound for more amps?

vwnate1 · #**305** 02-03-2015, 03:31 PM

I did this on several of my Mercs both NA and turbo chagred .

It was so long ago that I don't recall the details but you're fighting your self by trying with the belts in place .

As I mentioned earlier , the higher out put alternator is still worthless until you get a BOSCH branded voltage regulator , then even the weeny 55 Ampere original ones are just fine .

HUGO and other off brand voltage regulators never raise the voltage high enough to get full charging , especially around town where 99 % of all driving occurs .

Try installing it with the bent adjuster fixed and no belts then see .

Hit Man X · #**306** 02-03-2015, 03:40 PM

Quote:

Originally Posted by JamesDean

I did it on my 300SD and 420SEL, neither had a problem mounting.

Maybe you could take some photos and post up so we can see what is going on?

Same, my SD and 560 both have this alternator (and a few E23 BMW now)...I encountered no install issues. You can actually run more than one thing and have the car charge at idle.

Quote:

Originally Posted by sassparilla_kid

Why not just get a stock alternator rewound for more amps?

I have never had good luck with idle power with small case alternators 'rewound' for higher maximum amperage. A bigger case just works better all around.

JamesDean · #**307** 02-03-2015, 03:49 PM

Generally...re-winding for more peak output will reduce the low RPM output in most cases.

funola · #**308** 02-03-2015, 04:02 PM

Quote:

Originally Posted by fahrvergnugen

I appreciate the response, but have you done this swap? It doesn't bolt in as easily as the original. Some folks in this situation thread mentioned that as a way around the problem, but it hasn't worked so far.

I installed an Eagle Elec 120A alternator on my 83 approx 4 years ago and did not have any problems. Did you compare your old alt to the new alt as far as clocking? I do not remember the details of the install but I think you have to have to install the alt mount and the alt as an assembly. Try it with the belts off, you don't want to be fighting them to align the bolts

JamesDean · #**309** 02-03-2015, 04:08 PM

Quote:

Originally Posted by funola

I installed an Eagle Elec 120A alternator on my 83 approx 4 years ago and did not have any problems. Did you compare your old alt to the new alt as far as clocking? I do not remember the details of the install but I think you have to have to install the alt mount and the alt as an assembly. Try it with the belts off, you don't want to be fighting them to align the bolts

I can't remember if I had to clock the SD's alt. I think I had to clock the 420SEL's alt. Both were a long time ago.

But I think you are right. The bracket goes on the alternator, then the assembly gets installed. I do remember having to wiggle things around a bit but it was not a monumental fight.

fahrvergnugen · #**310** 02-03-2015, 06:07 PM

Thanks for All the suggestions so far, putting the bracket on the alt was the bit I had forgotten. However, I am still having trouble getting the top bolt on. The 'dent' in the top Bracket needs to be deeper, I'm still hitting the water outlet. I am considering notching it out so that it will clear more easily.

JamesDean · #**311** 02-03-2015, 07:04 PM

Quote:

Originally Posted by fahrvergnugen

Thanks for All the suggestions so far, putting the bracket on the alt was the bit I had forgotten. However, I am still having trouble getting the top bolt on. The 'dent' in the top Bracket needs to be deeper, I'm still hitting the water outlet. I am considering notching it out so that it will clear more easily.

I do remember some difficulty with the top bolt. It lined up I just had to jimmy it enough to get the bolt through.

Is this on a 123 or 126?

Hit Man X · #**312** 02-03-2015, 07:30 PM

Quote:

Originally Posted by JamesDean

I can't remember if I had to clock the SD's alt. I think I had to clock the 420SEL's alt. Both were a long time ago.

But I think you are right. The bracket goes on the alternator, then the assembly gets installed. I do remember having to wiggle things around a bit but it was not a monumental fight.

I had to reclock it for the 560. It ran a whopping $7 at my local shop.

The Eagle Electric unit I bought was junk. Idle output was comical...worse than the 65A I removed, used it as a core on a Bosch reman.

fahrvergnugen · #**313** 02-03-2015, 07:31 PM

83 300td, w123.

JamesDean · #**314** 02-03-2015, 07:50 PM

Quote:

Originally Posted by Hit Man X

I had to reclock it for the 560. It ran a whopping $7 at my local shop.

The Eagle Electric unit I bought was junk. Idle output was comical...worse than the 65A I removed, used it as a core on a Bosch reman.

I did the re-clocking myself. It was pretty easy. 8 screws IIRC and it came out.

I've been through a few alts before getting good ones. The first 143A I got from Advance Auto for the 190E failed. So did the second...but the third has been fine for 5+ years now.

The 300D's first 143 I failed to properly torque the bolts on after I re-clocked it...and it failed sometime during the week. Ended up driving home with no power. Battery dropped all the way down to 5V by the time I was home lol.

The 150A Bosch I bought on ebay has been fine.

No complaints on the AL129x's I put in. Both were from AutoZone.

funola · #**315** 02-03-2015, 08:19 PM

Quote:

Originally Posted by Hit Man X

I had to reclock it for the 560. It ran a whopping $7 at my local shop.

The Eagle Electric unit I bought was junk. Idle output was comical...worse than the 65A I removed, used it as a core on a Bosch reman.

Can you provide details how you did the test on idle output? The only test I did was idle voltage. Old alt was putting out 13.8 14.0 v. The Eagle elec 14.3 v.