Alternators - Remanufactured by Bosch vs Locally Remanufactured?

[Jlaa]

Gents - any opinions sourcing alternators?

I wish to obtain a 150amp alternator for my 500E and store it on my shelf - in preparation for the eventual time when my original 110A alternator fails. From various threads, I gather that MB part 010-154-83-02 (from this thread) 150A fits our cars.

This alternator is no longer available new and is available as Bosch remanufactured AL0785X. I have read lots of stories about unreliable remanned alternators. Anyone have any opinions on one of the following two choices:

• Obtain a Bosch AL0785X reman alternator
• Obtain a used 010-154-83-02 alternator from the junkyard (like this one) , take it to a local alternator remanufacturing specialist, and have it rebuilt?

Note - If I obtain a used alternator, I am not sure how to cosmetically restore the cast aluminum either. Perhaps with an air-powered needle scaler tool and/or lots of brake parts cleaner and a brush?

Thanks

 

[gsxr]

Jlaa, could you share some of the stories / concerns with the Bosch remanufactured units? I hadn't heard about this until your post. Also - were those for Mercedes-specific applications, or non-Mercedes?

Not sure if it helps, but there are several different 150A part numbers that will work. However, some will need to be "clocked" to fit on the M119 so the terminals don't touch things they shouldn't (especially for cars that have the engine oil cooler installed).

Cast aluminium: Media blast, after disassembly?

 

[Jlaa]

Jlaa, could you share some of the stories / concerns with the Bosch remanufactured units? I hadn't heard about this until your post. Also - were those for Mercedes-specific applications, or non-Mercedes?

Thanks!

• @gerryvz Bosch Reman w126 alternator diode failure - Alternator/Generator bad? Best Upgrade to 150A ? | Electrical, CAN and Wiring
• Porsche 993 Bosch Remans failing - Alternator Woes - Rennlist - Porsche Discussion Forums
• More Porsche Bosch Reman failures (from the esteemed Steve Weiner (RIP)) - Rebuilt (Bosch) alternator woes - Rennlist - Porsche Discussion Forums
• BMW Bosch Remans failing - https://www.e46fanatics.com/threads/repeat-bosch-alternator-failure.741771/
• More BMW Bosch Remans failing - Repeated alternator failures - help with diagnostics

Hmmmmmm......

 

[gsxr]

Thanks for the links!

Interesting there does not seem to be any common denominator, or at least nobody has done failure analysis beyond "the reman alternator failed". OK, fine, but what exactly failed? The rotor and stator should last a very long time, the typical wear items are the VR/brushes and slip rings, and perhaps a blown diode from a reverse-lead jump start.

Pity nobody digs into this deeper to see if there's something obvious, like using cheap/no-name VR's.

 

[Alphasud40]

Quality of reman components has gone down post pandemic. It even affects OEM suppliers remain parts. When it comes to alternators I am more inclined to purchase a used one and replace the brushes and bearings over buying a rebuilt one.

Even if you send it to a local rebuilder the quality of their replacement parts can be sketchy. Not so much the bearings as you can still source good bearings but the VR assembly made with off shore components or even counterfeit components is more of an issue. That’s what I ended up doing on my Cayenne Turbo. Bought a used alternator and replaced the brushes and bearings. Actually pretty straightforward DIY thing which will save you money and grief.

As far as reconditioning the housing media blasting or just cleaning and painting with engine paints designed to look like fresh casting are available.

 

[Jlaa]

Thanks for the comments. I guess a big question (which I don't have the answer to) is what is all replaced with a "Bosch Remanufactured Bosch Alternator"? I don't really know. I've never had one apart, but from what I can gather, the following is a list of item that MAY be replaced.

• Diodes
• Brushes
• Brush Retainer
• Slip Rings
• Bearings
• Voltage Regulator
• Pulley
• Resistors
• Bolts

I guess the reason why remanned alternators are so variable in quality is because some of the above list are often just "inspected and left alone"!!!!

Here is a statement from Bosch's website, which states: "Bosch Remanufactured Alternators have more new parts and are performance tested to ensure longer, more reliable operation with maximum performance."

Remanufactured Alternators - Remanufactured Alternators - Bosch Auto Parts - Liferay DXP

Bosch Remanufactured Alternators have more new parts and are performance tested to ensure longer, more reliable operation with maximum performance.

www.boschautoparts.com

What does not instill confidence is the fact that Bosch doesn't really mention WHAT is all replaced, just that they replace more (than others). Hmmmmm.

Another route I could take is to get a used one (like you suggest, @Alphasud40) --- and maybe taking to to my local remanufacturer and having them go through it? And, if I do that, then the question is, do I:

• Get a used 010-154-83-02 (150amp) from the 1999-2001 ML M113 chassis
• Get a used 009-154-19-02 (90amp) original to our M119 cars and have it rewound to have higher output

Hmmmm. Maybe I will give my local guy a call (Alternators Unlimited in Berkeley - apparently they have been in biz for 49 years).

https://www.yelp.com/biz/alternators-unlimited-berkeley

 

[gsxr]

I guess the reason why remanned alternators are so variable in quality is because some of the above list are often just "inspected and left alone"!!!!

+eleventybillion. High-volume rebuilders may only replace what has failed or is visibly worn - that's how they make money. Maybe they always install new bearings and VR. Maybe.

• Get a used 010-154-83-02 (150amp) from the 1999-2001 ML M113 chassis

YES!

• Get a used 009--154-19-02 (90amp) original to our M119 cars and have it rewound to have higher output

NO!! Rewinding for higher output almost always results in little, if any, increase in the output at idle. You want to start with a unit that already has the higher idle output (150A).

 

[Jlaa]

+eleventybillion. High-volume rebuilders may only replace what has failed or is visibly worn - that's how they make money. Maybe they always install new bearings and VR. Maybe.



YES!



NO!! Rewinding for higher output almost always results in little, if any, increase in the output at idle. You want to start with a unit that already has the higher idle output (150A).

Got it thanks. For what it is worth, I found this on the Amazon listing for Bosch Remanned alternators w.r.t. what Bosch Remanned Bosch alternators have replaced. Note that the only things that are 100% always replaced are clutch pulleys, bearings, and brushes. Slip rings are replaced or machined. Everything else, including voltage regulators, is just checked.

https://www.amazon.com/Bosch-AL0785X-Alternator/dp/B000BZGMJW

 

[Alphasud40]

Actually I’m okay with the Bosch reman approach. Like I said I feel more comfortable if that was the only thing replaced vs. one that needed a new diode assembly and a regulator. I have seen very little electronic failures in alternators. It’s almost always a bad bearing or brushes that have worn out. I have seen more failures of new or rebuilt alternators with bad diodes or bad VR units. Even after taking all precautions to make sure they receive a gentle break in with a fully charged battery. New electronics have to season. If they make it through this then they will last the duration. Rebuilders like Bosch have realized this. Not only does it make it more economical on the front side but more economical on the back end with warranty claims.

 

[Alphasud40]

If you do go the route of getting a spare alternator I would install it and leave it in service for a while then remove and place on the shelf. Maybe give the one in service to the shop and have them inspect and repair as needed and put it back into service and place the new one back on the shelf. Then you know you will have a good unit.

 

[gsxr]

If you do go the route of getting a spare alternator I would install it and leave it in service for a while then remove and place on the shelf.

I was thinking the same thing. Install the reman 150A and use that for a while. Then either leave it in (and keep the original as a spare), or swap it.

 

[dreaming.haze]

FWIW, I picked up a reman 143A alternator the other day for my 92 300TD. Came factory with a 70A unit, so 143A has been a great upgrade. Purchased mine off eBay (OEM MERCEDES Alternator 0091545602 Bosch S420 S500 S600 0123510018 for sale online | eBay). P#: 010 154 71 02 88.

Unsure on when this reman was completed, but based on packaging it does look a bit older. Been running for the past couple of months without faults or issues, but noted above of the differing quality depending on what was found in the reman process itself.

Out of curiosity, for failures of certain alternator functions, what would a diode failure or regulator failure look like?

 

[gsxr]

Out of curiosity, for failures of certain alternator functions, what would a diode failure or regulator failure look like?

Regulator failure typically results in zero charge / output, the alternator simply doesn't work. But it shouldn't drain the battery. A new VR typically fixes this.

Diode failure may result in draining the battery when parked, along with "dirty" power supplied... high voltage, spikes in voltage, audible RFI/EMI whine, probably other stuff too.

 

[Alphasud40]

FWIW, I picked up a reman 143A alternator the other day for my 92 300TD. Came factory with a 70A unit, so 143A has been a great upgrade. Purchased mine off eBay (OEM MERCEDES Alternator 0091545602 Bosch S420 S500 S600 0123510018 for sale online | eBay). P#: 010 154 71 02 88.

Unsure on when this reman was completed, but based on packaging it does look a bit older. Been running for the past couple of months without faults or issues, but noted above of the differing quality depending on what was found in the reman process itself.

Out of curiosity, for failures of certain alternator functions, what would a diode failure or regulator failure look like?

View attachment 199504

A bad diode will cause noise at idle that will sound like a moan which will increase in frequency as you rev the engine. Noise is created by one of the phases being shorted. Will still produce charging voltage. Easily detectable with a charging system tester. Bad VR will usually cause a no charge situation but I have had a few fail where they produce full field current causing voltage spikes 16 volts and higher.

 

[Jim Rosenthal]

I have had mostly good luck with reman alternators, but I buy them from local shops who will stand behind them. Specifically, PASCO here in Annapolis.

As far as cleaning up an old alternator, if you can find someone who does dry ice blasting, that will make it look like new, and no residue. Dry ice blasting is amazing. The only problem may be it is a small job- maybe group it with some other items that need cleaning up.

 

[gerryvz]

Thanks!

• @gerryvz Bosch Reman w126 alternator diode failure - Alternator/Generator bad? Best Upgrade to 150A ? | Electrical, CAN and Wiring

I will say, in relation to this post that the @Jlaa is referring to: Alternator/Generator bad? Best Upgrade to 150A ? | Electrical, CAN and Wiring

Back in the fall of 2008, my 560SEC's original alternator failed. I had it replaced with a Bosch reman, installed by MBI Motors in Portland. They were preparing the car for me to drive it from Portland to my new home in Houston.

Within literally one mile of leaving the MBI shop, the alternator failed. I was crossing the Willamette River from MBI on the East Side of Portland into downtown Portland. After crossing the bridge, I pulled over and had the car towed back to MBI. They diagnosed the "Bosch factory rebuilt" alternator as a bad one, and replaced it with another Bosch factory reman unit the next day.

That Bosch factory reman worked until 2019, per the above post. The reman unit I installed then, has worked fine, although I haven't put a ton of miles on the SEC since 2019.

I stand by my earlier statements that at least for the M117 Bosch factory reman units, they are not nearly as long-lasting as the original units.

 

[Jlaa]

I will say, in relation to this post that the @Jlaa is referring to: Alternator/Generator bad? Best Upgrade to 150A ? | Electrical, CAN and Wiring

Back in the fall of 2008, my 560SEC's original alternator failed. I had it replaced with a Bosch reman, installed by MBI Motors in Portland. They were preparing the car for me to drive it from Portland to my new home in Houston.

Within literally one mile of leaving the MBI shop, the alternator failed. I was crossing the Willamette River from MBI on the East Side of Portland into downtown Portland. After crossing the bridge, I pulled over and had the car towed back to MBI. They diagnosed the "Bosch factory rebuilt" alternator as a bad one, and replaced it with another Bosch factory reman unit the next day.

That Bosch factory reman worked until 2019, per the above post. The reman unit I installed then, has worked fine, although I haven't put a ton of miles on the SEC since 2019.

I stand by my earlier statements that at least for the M117 Bosch factory reman units, they are not nearly as long-lasting as the original units.

Yikes! May I ask what was the mode of failure of the less-than-one-mile-old Bosch Reman alternator?

I will note - I asked my local independent shop here that services Porsches and Mercedes this morning. This is what he had to say about Bosch remanufactured Bosch alternators (from a Porsche perspective).

 

[gerryvz]

Yikes! May I ask what was the mode of failure of the less-than-one-mile-old Bosch Reman alternator?

Failure to charge the battery. Instrument cluster lit up like a Christmas Tree.

It is possible to drive for 75+ miles in a W126 just on battery power alone, though. I know .... I've done it twice now. Once here in Maryland (lost alternator belt driving from Annapolis to Dulles Airport ... you helped me out with tools to install new belt in airport garage), and once in Texas driving from Houston to Centerville (@alabbasi remembers this; I installed replacement belt in parking lot in 20 minutes).

 

[Jlaa]

Failure to charge the battery. Instrument cluster lit up like a Christmas Tree.

It is possible to drive for 75+ miles in a W126 just on battery power alone, though. I know .... I've done it twice now. Once here in Maryland (lost alternator belt driving from Annapolis to Dulles Airport ... you helped me out with tools to install new belt in airport garage), and once in Texas driving from Houston to Centerville (@alabbasi remembers this; I installed replacement belt in parking lot in 20 minutes).

Ha! I remember that!!! Now that you mention it was for your w126 and not your w124 (you probably told me at the time and it went in one ear and out the other) I realize that I should have lent you the Krikit tension gauge too!!

 

[gerryvz]

Ha! I remember that!!! Now that you mention it was for your w126 and not your w124 (you probably told me at the time and it went in one ear and out the other) I realize that I should have lent you the Krikit tension gauge too!!

I have a real "Krikit" here in my tool chest at home, and have used it exactly ..... ONCE.

With v-belts as used on the W126, all you have to do to know the belt is exactly tight enough is to twist it 90 degrees at a point directly between two pulleys. If it twists 90 degrees with some resistance, and won't go much beyond that, it is tight enough. If the belt easily twists 90 degrees and you can go beyond that with little difficulty, it is too loose.

The SEC is still running on the belt that I replaced in that Dulles parking garage, several years later. Zero issues. But I did replace the spare v-belt set that I had removed for cleaning (and never put back into the trunk), back into the trunk ... with a fresh set of new belts.

I'm hoping you did receive the tools that I sent back to you via Priority Mail.......

 

[gsxr]

Failure to charge the battery. Instrument cluster lit up like a Christmas Tree.

Likely a failed VR. I'm curious if the VR was not replaced, or if it was replaced with a substandard component.

 

[gerryvz]

The alternator had a new voltage regulator included with it as part of the "reman." MBI did not re-use the old VR.

 

[gsxr]

The alternator had a new voltage regulator included with it as part of the "reman." MBI did not re-use the old VR.

I was wondering if the first Bosch reman process didn't replace the VR (as they normally should!). MBI likely swapped the entire alternator and didn't pull the back cover off to check what VR was present? Or, the new VR experienced near-immediate failure... which makes me wonder if the new VR was genuine Bosch or not.

 

[gerryvz]

Definitely the Bosch factory reman was an authentic unit, with a Bosch VR in it. I saw the box and have the invoice for it that the tech showed me at the time. Bosch wouldn't use a non-Bosch VR in their own factory remans. They did swap the entire alternator in wholesale, though. I doubt if the back cover was pulled off, but heck, this was a long time ago.

 

[Jlaa]

Well, I stopped by Alternators Unlimited and picked up a remanufactured "Alternator for a 2000 MB ML430". It was inexpensive - only $160 + $40 core. Not sure if I got ripped off or what I got is legit. I can return it.....

Alternators Unlimited --- seems legit. Its a small building and there's one guy (the owner since 1975) rebuilding everything himself. Lots of mechanics go here as evidenced by the wall of cards. The son is the one who does the sales and the one who helped me...... he doesn't seem ultra-technical like the dad.



This is what I got. They had two of these that they rebuilt themselves but neither seem to have the Bosch-embossed black plastic cover. They had one more remanned alternator for Mercedes that DID have the Bosch black plastic cover, but it was a 120amp model, not a 150amp model.

The sales-son indicated that they typically don't replace the case nor the diodes since, in his words, "Original diodes often cannot be beat". That said, the alternator DID have a Bosch voltage regulator inside. Taking off the back cover --- things looked nice? But I have no idea how to tell if this is a quality unit. The brushes measure 10.67mm.



The sales-son ran it on the machine for me twice with two setting --- once w/ the ammeter at 40amp range, and once w/ the ammeter running at 80amp range at my insistence.

In this first run, he verified that the voltage spit out by the alternator was 14.53 volts. He told me that the alternator spit out over 80amps (he said pegging the needle), and that's what he expected so that it meant the alternator was good. I have no idea how fast the electric motor was running or what the size of the pulleys were, so I have no idea if this was supposed to simulate idle speed or what, but I should have asked. Confusingly, I did not understand at all why the machine was set to "40 amp range" when Sales-Son pointed to the needle at 80+ amps. He was really nice and friendly, but he said, "that's the way we test it - we set this super old machine to 40." .

He ran the machine again with the amp range knob set to 80 amps and he said the alternator was spitting out 150amps (again doubling the number which I didn't understand?). Maybe because the alternator spits out AC and not DC?

Anyways, for only $160 + $40 core, I was fairly pleased (especially as a Bosch branded Bosch reman alternator would run me at least $350-$385, shipped to my door) but I still wanted to double check, so I decided to take it to a local autoparts store to test the alternator. OMG I had no idea this would be such an ordeal. I called 4 each of Autozone, NAPA, and O'Reilly. All the Autozones and NAPAs either said they don't bench test alternators anymore or that their machine was broken. Only O'Reilly bench tests alternators around here, and apparently O'Reilly rolled out new bench-testing machines chain-wide that are made for KISS stupid operators. The tester apologized to me profusely that the new machines don't give me an amps rating ---- it only gives me a PASS or FAIL. We input in the year / make / model of the car into the computerized bench tester (where I suppose there is a database of criteria that the machine looks for) and the machines spits out PASS or FAIL. This alternator PASSed, although I have no idea what that really means.



So what say you guys? Keep or Return?

 

[Alphasud40]

I would keep it and install on your car and run it for a few weeks. If it works for a few weeks then you will have a good one that should last a long time. The remark from the shop about the diodes is spot on. They don’t make them as good as they used to and a seasoned diode will probably last longer than a new diode pack from the land of one hung low. Napa learned their lesson the hard way by replacing all the internals during the rebuild process. I replaced countless alternators due to early death syndrome. Even had one that was shorted right out of the box. It’s quite dramatic when you hook up the negative terminal to witness an explosion of sparks not to mention the risk of exploding the battery which happened to me once.

 

[Jlaa]

I would keep it and install on your car and run it for a few weeks. If it works for a few weeks then you will have a good one that should last a long time. The remark from the shop about the diodes is spot on. They don’t make them as good as they used to and a seasoned diode will probably last longer than a new diode pack from the land of one hung low. Napa learned their lesson the hard way by replacing all the internals during the rebuild process. I replaced countless alternators due to early death syndrome. Even had one that was shorted right out of the box. It’s quite dramatic when you hook up the negative terminal to witness an explosion of sparks not to mention the risk of exploding the battery which happened to me once.

Thanks!!

And UPDATE - I am definitely going to keep this alternator. I was peeking in the holes around the case and noted that the word "BOSCH" with the Bosch Logo is in fact cast into both case halves! Score!

 

[skikrazey]

When I had my 93 500E, the starter was going bad. My Indie Repair Shop recommended having the starter rebuilt locally by an Amish shop. They had bad luck with Bosch reman units. I elected to have the alternator sent out as well. Both were original units to the car, which had 151,000 on the clock. The price was $250 for both units to be rebuilt. The Amish did a great job rebuilding both the starter and the alternator.

 

[Alphasud40]

When I had my 93 500E, the starter was going bad. My Indie Repair Shop recommended having the starter rebuilt locally by an Amish shop. They had bad luck with Bosch reman units. I elected to have the alternator sent out as well. Both were original units to the car, which had 151,000 on the clock. The price was $250 for both units to be rebuilt. The Amish did a great job rebuilding both the starter and the alternator.

I used to live close by to the Amish starter and alternator shop in fivepointville I believe. Funny watching the Amish working in bare feet in a shop environment. Amish are very frugal but they always bought the best quality components.