Why Do the alternators seize

[uk pan rider]

Hi All,
I have owned quite a few Pans over the years and have suffered from the annoyingly regular alternator problem.
But, Why?
I don't think I have been unlucky, I think there is a design fault. (state the obvious) But has anyone got the answer as to why. I always thought it was a question of excessive heat build up. But it seems as if it is less of a problem to US pans. We don't get a lot of heat here, and we only get salted roads in the winter. I don't ride much in the winter.
The alternators I have changed have all been 40 amp'ers and all have had cracked rear cases, and have been impossible to turn over by hand, even though the bikes have been riding fine.
How can I prevent this happening again. I am pulling another cracked case alternator from my latest Pan, and looking hopelessly round for a replacement, as ?600 is too dear for a new unit.
Has anyone sited another type of alternator anywhere else on the ST1100 engine. (front pulley drive, cam pulley drive etc)

 

[Firstpeke]

There is alternator reconditioner in Kent and I can't remember who posted the details..... maybe Trosty?

Do a search.... I'm going to bed.....

 

[wjbertrand]

I think they use a lot more salt on the roads in the UK and I think you guys are more all-weather riders than here in the US. The location of the vented 40A unit close to the road spray predisposes the unit to corrosion. I've never heard of this problem happening in the US. It's interesting that on the 1300, the alternator is relocated high and dry up in the "V" of the engine. Gotta be hotter up there than down where the 1100's alternator is, yet failures on the 1300 seem pretty rare.

 

[jim'll break it]

I used a bandit alternator on mine, €20 from the local breakers, i swapped the pans armature over into the bandits one because the shaft couplings were different,
they seem to corrode between the outer,case and the iron stampings of the stator coil
changing the armature is fiddly and you need to be careful pressing the cases apart but it could be done in an evening
Look familiar?

I think the 1200 is the one but im not exactly sure, have a look in your breakers, the cases are identical as are the rectifiers, regulators and electrical connections

 

[George]

I used a bandit alternator on mine, €20 from the local breakers, i swapped the pans armature over into the bandits one because the shaft couplings were different,
they seem to corrode between the outer,case and the iron stampings of the stator coil
changing the armature is fiddly and you need to be careful pressing the cases apart but it could be done in an evening
Look familiar?

I think the 1200 is the one but im not exactly sure, have a look in your breakers, the cases are identical as are the rectifiers, regulators and electrical connections

Les, will you cross-post this to my-mc next time yur up there?

Now THAT is a handy piece of info!! I suspect the Bandit alternator cases will get pretty rare pretty quick.

 

[keith3po]

Anyone else used the Bandit alternator?

 

[George]

There is another thread on here where Trosty documents the rebuild from one of the vendors in England. That one sez a lot about non-OEM internal parts costing ? instead of $.

As to WHY the case cracks in the first place, gotta have something to do with weather/road conditions. I'm gonna take a close look at all three of my 40 ampers for corrosion.

Has anyone bothered to change out the brushes in their alternator? 12 31105-MAJ-G41 HOLDER ASSY,BRU!H

 

[George]

Ought'a mention, STick's amp has <50,000 miles, lipSTicks' ~125,000, and STanley's (nee ReSTored) 130,000. All operate apparently fine at this juncture.

 

[keith3po]

Build up of rust on internal's cause's outer case to crack this is mine.



Got a second hand one on it now but would like to rebuild old one any info on the Bandit one would be good.

Oh should point out it was working perfectly, only noticed crack while doing some maintenance.
Worth putting on your inspection list.

 

[George]

Here's a link to Trosty's thread about 1300 alternators. Also a note in there from Norm about Nippon Denso alternators, providing much info.

At the least, Honda is overcharging on parts. So what else is new.

 

[jim'll break it]

I should have taken photos and posted up a step by step, i would say a hydraulic press or pullers is a must when separating the cases, i changed the oil seal on the shaft while i was at it as well as the bearings,

 

[keith3po]

I should have taken photos and posted up a step by step, i would say a hydraulic press or pullers is a must when separating the cases, i changed the oil seal on the shaft while i was at it as well as the bearings,

Thinking of buying a Bandit alternator off Ebay about ?30/?40 i just need the casing as mine is cracked, anything i should know before buying?
Cheers Keith

 

[jim'll break it]

some models are different, i went to my local breakers and there were about 4 different types on the bandit 12 shelf, id recommend you do the same to make sure you get the right one,
if the cases are cracked i guarantee the stator coil is corroding, thats what causes the cracking, your best bet is to swap the armature of the bandit unit with the one out of your pan,
be careful removing the rectifier, the stator wires can snap if bent too much and be careful pressing the cases apart, it'll take quite a bit of pressure to get em unstuck

 

[Imrubicon]

Maybe get a ST1300 as that doesnt seem to be a problem ????

 

[keith3po]

Maybe get a ST1300 as that doesnt seem to be a problem ????

Hmm maybe oneday, but not just yet.

 

[Andi As]

Hi Jim
If that is the Bandit alternator do you have a better image so that I might be able to interpret the factory label?

EDIT: Hmmmmm..........

http://www.ebay.co.uk/itm/SUZUKI-BANDIT-600-ALTERNATOR-GSF-00-S-/110699430860?pt=UK_Motorcycle_Parts&hash=item19c63343cc

 

[jim'll break it]

Sorry for taking so long to reply, been busy lately
next time i have it out of the bike ill take some shots of it, with a bit of luck that wont be for a while though
someone over on mymc said the gear could be removed from the armature shaft and the splines are the same but mine was a solid shaft with the gear integral to it
i still have it and i just checked, just to put that one to bed,
im kinda sorry now that i didnt document the part numbers, i think i even took off the denso decal, i red oxide primered the casings and stator to try and keep the corrosion down
but i didnt know it was something no-one else had tried at the time (this is my first pan, bought for €400 as a fixer upper, its a 98 abs model btw)

 

[Norm]

The problem with case splitting is due to the tight fit of the iron stator core into the slip ring end housing. In fact, removing the stator from the housing on an alternator which has not been the victim of excessive corrosives is a real bear! It is very, very difficult to extract the stator from the housing without destroying the stator.

The iron stator core corrodes, apparently due to the corrosive road chemicals more prevalent in UK, which expands the iron core until the aluminum alloy housing splits.

I use products called "Fluid Film" and LPS #3 which are wax bases anti-corrosion sprays intended to coat surfaces in order to exclude corrosives. The up-side of the wax is that it seldom affects plastics, "rubber", insulation, etc. Were I a UK owner, would use a wax based spray with care in order to attempt to coat the stator core while avoiding coating brushes and slip rings. I can post some photos of a disassembled 42 amp unit if it would be of value.

FWIW, that little ND alternator can be serviced by an alternator shop who can obtain individual parts for most of the alternator. Many shops, unfortunately will not service these alternators because their test bench accomodates only belt driven alternators and they do not wish to deliver an un-tested alternator to a customer who may find that the alternator does not perform.

I service these from time to time and can obtain parts excepting rotor and drive-end housing. The rotor can be repaired by some specialty shops who can replace the rotor's field winding, pole crowns (can't imagine what would require this), and slip rings.

Several of us have measured Suzuki Bandit alternators which appear to be the same little ND alternator however there are several variations of internal parts within these same frame sizes so I cannot be assured that the two are identical. Our local Suzuki dealer were less that cooperative when I asked to remove the alternator from one of their used bikes in the show-room. Can't imagine why.....

It would be ideal to pull one apart to compare internals however I think that George has swapped parts?

The regulator is no longer available through my sources so am exploring import from Asia but qualities and shipping are an issue. In the mean time am converting another rectifier to the ST1100 configuration which seems a better solution despite the extra work it is still the more economic solution. Given that I'm retired and not doing this for a profit, a bit more time doesn't matter as it gets someone back on the road at modest cost.

I'm still learning on these alternators (no one ever knows it all) and hoping to find other sources.

Anyone have a 60 amp ammeter/amp clamp and interested in doing a load test? I'm still gathering data and can talk about how to add loads if one lacks a heavy adjustable load.

Norm

 

[Simon]

I am in the process of fitting a Bandit alternator to my 1100 - beware, the mounting bolts are in a different position, and the ST shaft is larger than the Bandit one.
Almost finished my conversion prototype.
Fingers crossed, and if it all works out well I'll be able to provide detailed instructions and all the parts require to convert to a cheaper alternator on the ST