dead alternator brushes; alternative brushes (147 TS Magneti Marelli alternator)

[johnl]

So I had the 'Low battery' warning, followed a shortish while later by the engine just shutting off, and a dead battery. Of course this was at a traffic light facing uphill with lots of surrounding traffic and other drivers being less than understanding or sympathetic...

Anyway, on getting the car home (with another fully charged battery), I nonchalantly removed the plenum chamber, which went swimmingly with zero problems (other than all the blood, the sweat, the tears, the cramps, the swearing...). Then I removed the alternator (which was easy...). On inspection the brushes were very short and the slip rings worn and blackened (as expected). I have another 147 I recently acquired for parts, so again I nonchalantly removed the plenum etc (you'd think it would be easier the second time knowing the lay of the land under there, but it was actually more difficult...). I then extracted the alternator, and held it aloft...

I knew this alternator worked, but on inspection it became apparent that it had only maybe 20 or 30 thousand kms left in it (if I was very lucky). Same deal, short brushes, just not as short. At least this unit had better slip rings, was silent and the bearings seemed perfect (which on the other one were questionable if not yet bad). The last thing I ever want to do at the moment is remove the alternator ever again, so not wanting to risk another SH unit, or pay mega bucks for a new one, I started looking for new brushes, and came up with exactly nothing, nowhere. Apparently they are an unusual and rare size, why wouldn't they be...

Plan B, I ventured to the auto electrician and made a pest of myself until they found me some brushes from some Bosch alternator. These are too big, but that is what I was looking for. The original brushes were 3.9mm X 7mm X ?mm length, with a side exit 'pigtail'. The Bosch brushes were 4.9mm X 8mm X 17mm with a side exit pigtail ('pigtail' being the cable attached to the brush.

I removed the old brushes. Then I sanded the new ones down until they fitted and slid smoothly in the brush slots (they sand easily, take your time and measure, measure , measure). I then drilled holes in the metal tabs to which the ends of the pigtails attach / are soldered (one hole per tab per pigtail), inserted the pigtails, wrapped them around a bit and soldered them in place.

This was all a bit fiddly but not too difficult. I filed little chamfers onto the curved ends of the new brushes so that they would fit into the wear slots in the old slip rings, to the bottom of the worn section (the new brushes are a bit thicker than the old ones). This was just to increase contact area while the brushes are wearing in, later they will (should) wear to the exact shape of the slip rings. The new brushes are a much better fit in the slides than the old ones would ever have been (quite a sloppy fit).

The brushes are Bosch GB610, cost $15.00. I don't know what alternators in what cars they are for.

As yet the alternator is still on the bench, I'll be fitting it tomorrow, with fingers crossed...

Regards,
John.

[Citroënbender]

You are ahead of me. I'm still limping along on the dying alternator.

Did you note any identification marks (eg, part number) on the brush-holder/regulator? There's a Polish supplier of almost anything and between them and another East European supplier called Alt-Star it's possible to dig up all sorts of cross references.

https://en.as-pl.com/
https://www.altstar.kiev.ua/index.php

[bazzbazz]

Was it a Bosh Alternator or Magnetti Marelli that you fitted the brushes to?

If it was a Bosch, replacement Regulator Modules (with new brushes) are available from here -

https://www.ebay.com.au/itm/Genuine-BOSCH-Voltage-regulator-F00MA45206/223413331835?fits=Model%3A156%7CMake%3AAlfa+Romeo&hash=item340478e77b:g:ShgAAOSwWkhcuapE&frcectupt=true

or here

https://www.ebay.com.au/itm/Alfa-Romeo-Gt-166-156-147-Fiat-Lancia-BOSCH-Alternator-Voltage-Regulator-1995/162567999221?fits=Model%3A156%7CMake%3AAlfa+Romeo&epid=27015393917&hash=item25d9cecef5:g:KT0AAOSwA~5ccsWH

They just screw on.

Just one thing, did the charge warning light illuminate on the dash display?

[Citroënbender]

Haven't found just brushes yet, but the whole reg/brush holder is neither uncommon nor dear.

MM/Fiat P/N 77365275 or 77365276 (tropicalised)

https://www.altstar.kiev.ua/index.php?pg=podbor&p=77365275

[johnl]

Bazz,
Both of my alternators are the same. The first marks I saw were moulded into the plastic back end cover, and say "Magneti Marelli" (and I just found a number inside the plastic end cover; 8362484.0).

"Magneti Marelli" is also moulded onto the plastic brush holder. So, I had just been assuming it was a MM alternator, until closer inspection reveals a dirty external sticker marked "Denso Made in Italy" with various ID numbers as well. "Denso" is also cast onto the aluminium casing. So...?

The new brushes are made for some Bosch alternator(s) of unknown application. I just hacked them about (carefully) to fit my alternator (MM or Denso? Don't really know...).

CB,
The only marks on the plastic brush holder thingy are "Magneti Marelli made in Italy" with no part numbers. There is a squat metal cylinder attached to the plastic holder marked "Denso L9106  A R22B30328 Malta" (once the dirt is removed...).

Thanks for the link to the regulator / brush unit (looks very similar but not identical, the rectangular mystery box is a squat metal cylinder on mine). I couldn't find any brush holder thingys anywhere for this particular alternator. Neither could the auto electrician find any listings for it on the databases he can access...

Regards,
John.

[bazzbazz]

Did the charge warning light illuminate on the dash display?

The reason I ask is that there is more than worn brushes that can cause your alternator not to charge, such as a dud diode pack!

I just don't want you to go through all the trouble of refitting everything only for it to be still faulty.

[Citroënbender]

I know the reg/brush holder you mean, trying to drag it up now but the Polish site is running at glacial speed.

This one? https://en.as-pl.com/p/ARE4020(MM)

[johnl]

Did the charge warning light illuminate on the dash display?

The reason I ask is that there is more than worn brushes that can cause your alternator not to charge, such as a dud diode pack!

I just don't want you to go through all the trouble of refitting everything only for it to be still faulty.

Thanks Bazz,
No warnings other than "battery charge low", or words to that effect. And no syptoms other than the engine abruptly cutting out and then failing to restart with an obviously very flat battery. I know there is potentially more to it than just brushes, but I'm taking the chance that the issue was brushes since they were visually stuffed, i.e. very short, with one having a dull rubbing surface, and blackened slip ring surfaces where the brushes were obviously were failing to properly contact the rings, i.e. an abvious fault very likely to cause poor charging. I really dislike auto electricals...

The polish part may well fit, but how long to order from Europe? I need to get the car back on the road ASAP, so I needed a local and quickly implementable solution (with luck on my side...).

-----------------------

For those yet to have the pleasure of attempting to access the alternator, there are supposedly two ways to do it, by dropping the subframe or by removing the plenum. I read a someone saying say they had tried it both ways and removing the plenum is easier, Hmmm...

I went from the top. This way the hardest part of accessing the alternator is removing the plenum chamber. The hardest part about removing the plenum is the two bolts beneath the plenum, which attach it to a brace. These are impossible to see, very difficult to find / feel, hard to get a spanner on, and with almost no room to swing the spanner. To add complication, AR has seen fit to provide an effective net of wires and cables in the vicinity around the bolts, which all get in the way.

For further misery, the bolts are zinc (?) plated, screwed into brass inserts in the plastic plenum. It seems the plating and the brass develop a keen fondness for each other and are very unwilling to be parted, i.e. I think there is a chemical reaction between the disimilar metals and they become very bonded...

I managed to undo three of these bolts from above, but couldn't (literally) crack the fourth from there (remember was doing this on two cars, so two plenums and so two X two of these bolts). For the fourth bolt I had to get underneath the car, which was fun due to my trolley jack giving up the ghost so I was unable to lift the car onto a high enough setting on the car stands. Even with my face against the bottom of the floorpan it was possible to get a socket onto the plenum bolt from below using a very long extension (all my extensions joined together). Even so, the offending bolt was still unbelievably tight and difficult to undo (I was expecting the plenum to crack, but it didn't happen). I would have tried this earlier in the day had the jack been working properly, and it's how I'd reccomend approaching these bolts. On replacement the bolts will be slathered in grease in the hope of avoiding similar seizure in the future.

There are also two bolts attaching the plenum to the underside of the manifold, just beneath manifold branches 1 and 4. These are not all that easy to access (at least not the one under branch 1, which is a bit of a stretch to reach under the manifold / plenum from the other end of the engine), but they pale beside the bolts on the underside of the plenum.

Oh, and there are a plethora of wires attached to the back and undeside of the plenum with little clips, which are a pain to undo until you get the knack of it (by which time your fingertips are very sore). When I removed the first plenum, once everything was detached I managed to wiggle it free and out, just. With the second plenum, it just wouldn't come out until I jacked the engine up on its' mounts by a few mm.

I'm confident that reinstalling all this will be an enjoyable and troublefree experience with no unexpected tribulations (I keep telling myself...).

Regards,
John.

[bazzbazz]

Next time do it from below, much less stressful. An extra pair of hands helps getting the alternator back in the bracket, but much easier than getting the plenum and all the other plethora out of the way. (Just my humble opinion)

It may not be quicker, just less stressful, and besides, your on your back rather than bending over, and if you get tired, you can cat nap. 

[Citroënbender]

WoodAuto have a cross to the Polish part number, it's one of their in-house codes. About £40 plus post.

https://www.woodauto.com/product/VRG47439

Does that picture match yours exactly?

[johnl]

WoodAuto have a cross to the Polish part number, it's one of their in-house codes. About £40 plus post.

https://www.woodauto.com/product/VRG47439

Does that picture match yours exactly?

Pretty much does.

Regards,
John.

[Craig_m67]

It may not be quicker, just less stressful, and besides, your on your back rather than bending over, and if you get tired, you can cat nap. 

Said the Bishop to the actress....

[johnl]

Next time do it from below, much less stressful. An extra pair of hands helps getting the alternator back in the bracket, but much easier than getting the plenum and all the other plethora out of the way. (Just my humble opinion)

It may not be quicker, just less stressful, and besides, your on your back rather than bending over, and if you get tired, you can cat nap. 

One of the reasons I decided to go in from the top rather than drop the subframe was specifically to avoid lying on my back working under a car, with too little space, and too little bodily flexibility (I can do it, but my back will likely be an issue the next day...).

So the alternator went back in this afternoon. I was going mad trying to get the 'new' alternator (from the donor car) to fit onto the lower bracket (through which the bigger of the two attachment bolts pass). I spent ages (and spilled blood) but just couldn't get the damn thing to slide onto the bracket. It seemed for all the world as if the alternator was too narrow to fit onto the bracket (which surely couldn't be right...). So, I re-extricate it and measure the two 'nators side by side. Sure enough, the gap into which the bracket fits in the alternator was more 1mm narrower on the donor unit, so couldn't possibly fit onto the bracket. But but but surely these things are mass produced to reasonably tight tolerances??...aargh, bloody Italians...

At least I found the problem before too long and had only gone slightly 'spare'.

What I found; there is a steel tube in one arm of the alternator body which is split along its' length and is 'spring loaded' into its' hole in the body casting. This split tube is a tight fit but it can be moved in or out using some force. I used a vice and a socket to move the tube about 2mm. This widened the gap into which the bracket fits, and it just fell into place on the bracket (well not quite, but it wasn't difficult). Tightening the bolt automatically pushes the tube into the correct position to suit the bracket width. Never seen this before...

Anyway, tomorrow the plenum goes back on. I am worried about the state of the four rubber induction tubes. They are old and hard and seem likely to be brittle. The other day I bought eight new hose clamps to use on these, because I'm not a fan of the clamps AR uses (for starters I don't have the correct pliers, but other than that just not a fan). However, the new clamps are too wide for the old indented clamp grooves in the tubes, and I suspect may destroy the likely brittle rubber when tightened.

I'm not convinced that re-using the old hose clamps on the old hard tubes will result in a good seal (even if I can get them to 'click' without the correct pliers, I may have to get some), so will probably use some 'Aviation gasket', or, consider replacing the tubes...

Regards,
John.

[bazzbazz]

One of the reasons I decided to go in from the top rather than drop the subframe was specifically to avoid lying on my back working under a car, with too little space, and too little bodily flexibility (I can do it, but my back will likely be an issue the next day...).

You don't drop the subframe, you remove the lower engine mount, giving you a large hole to work through to disconnect/undo everything. Then you support the engine with a trolley jack, undo the front engine mount (drivers side) and rotate the engine forward, pivoting on the gearbox mount, to give you the clearance needed to remove Alternator and insert new one through the same hole where you removed the lower engine mount.

What I found; there is a steel tube in one arm of the alternator body which is split along its' length and is 'spring loaded' into its' hole in the body casting. This split tube is a tight fit but it can be moved in or out using some force. I used a vice and a socket to move the tube about 2mm. This widened the gap into which the bracket fits, and it just fell into place on the bracket (well not quite, but it wasn't difficult). Tightening the bolt automatically pushes the tube into the correct position to suit the bracket width. Never seen this before...

What John is referring to here are the mounting bushings on the Alternator.

[Citroënbender]

Split sleeve, what I've always referred to as "slip and grip" for the way they take up clearance then stay solid. You get them in the mountings of some PAS and hydraulic pumps too.