Sturmey Archer AG3 dynohub terminal problem ?

[hoogerbooger]

Hi

( the pun is unintended)

Anyone out there an expert on the left hand side of the SA AG3 ?

just tried to remove the back wheel from an old bike I bought with an AG3 dynohub. One of the dynamo wire terminal nuts unscrewed ok. The other was rusty and the terminal turned with the nut. So have stopped to have a think about options to remove nut & refit later. The wheel can't be removed, unless the dynamo wires are removed.

The exploded parts diagram I've found do not show any detail for the terminal itself and how it's fixed to the armature.

So does anyone know how the terminal is fixed & if I should actually try to undo it... as in is it more likely to cause damage ?? (looks like there is a limit to dismantling , as I've read that I should not separate the armature and magnet)

....or is my safest bet to leave the spade and nut as they are jammed in place ( and hopefully still with electrical continuity), and cut that dynamo wire and install a connector ?? { would be a shame, but better a working dynamo than not]

[Brucey]

I would suggest that you fit an inline connector, assuming that you still have a working generator, that is. The main winding is made of a very thin solid copper wire and it is soldered directly into the back of the fitting; any turning of the stud tends to wring the wire off pdq. If you have done this then it is possible to effect a repair but it ain't easy.

FWIW one thing you shouldn't do is separate the magnet and the armature; this causes the magnet to demagnetise and the output of the generator will be reduced for ever.

cheers

[hoogerbooger]

Thanks & glad I stopped then. It's still working thankfully. So will search out a suitable connector.

Do you think there will be any option to secure the terminal stud later ? solder ? epoxy or not.

[Brucey]

you can cut a slot (e.g. using a junior hacksaw) in the top of both the stud and the nut. This is (once the nut is free) then used to hold the stud when tightening the nut. The old nut can be split off; just cut (or grind using a Dremel tool) the sides of the nut away.

At some point (in a criminally stupid attempt to save a few pennies I think) they changed the nuts from brass to steel and this caused nothing but trouble with seizures. The nuts are a standard thread (IIRC a BA thread) and can be replaced easily enough.

FWIW I recommend getting some eyelet type crimp terminals attached to the hub, and then using the wire receptacle in the terminal as a socket for a small blade or other male terminal. For example I have used a long 3mm blade, folded double, as a male terminal. This arrangement has the great benefit that the wires don't get ripped off if you should take the wheel out or otherwise tug on the wires without disconnecting them first; they just pull out. I have used this arrangement for many tens of thousands of miles with no issues.

cheers

[hoogerbooger]

Thanks again.

1971 brochure shows nuts as part: HMN 140 - 2BA nut

found brass 2BA nuts online so if I find a dremel eventually and cut off I'll replace with brass nuts as well trying to rig up the blade terminals suggested. ( belt and braces)

[fausto99]

AG3 dynohub? I'm probably being dense but I don't know that one. I've only come across a GH6 dynohub. Someone enlighten me please. Is there a pdf out there in www-land?

[Brucey]

AG3 dynohub? I'm probably being dense but I don't know that one. I've only come across a GH6 dynohub. Someone enlighten me please. Is there a pdf out there in www-land?

AG is the dynohub version of AW, i.e. 3s rear dynohub





cheers

[fausto99]

Thanks

[rjb]

More useful information when you come to adjust the left hand cone here.
viewtopic.php?f=5&t=123754&p=1256149&hilit=Sturmey+Dynohub#p1256149

[hoogerbooger]

a couple more questions before I take my 1978 AG apart. Looks to me like the hub has done nothing for many years:

1) Would part HSA 284 be the right replacement main axle bearings ?
When I rotate the back wheel it sounds like the bearings are no longer retained in a cage. I will soon see, but am presuming I will need to replace bearings/cages. A 1971 brochure shows the main axle bearings as: HSA 103 Ball cage & I can't tell if this is just the code of the cage or with bearings. I can't find part HSA 103 to buy though. But can see a HSA 284 on the modern equivalent to the AW

2) size of bearings on 'inner dust ball ring ??

3) read somewhere that standard lithium bearing grease may be too thick and all grease should be used sparingly. So do I need a specific Sturmey archer grease or is there a more widely available grease type that is suitable

4) hub has an oil cap. 1971 brochure says use a few drops of SAE 20 Mineral Oil at least once a month. Elsewhere I've seen SAE 30 rather than SAE 20. So is there an easily available good oil ? and presumably its advisable to inspect and clean/remove at least the worst of any dried up or thick crud, rather than just add new oil ?

[Brucey]

a couple more questions before I take my 1978 AG apart. Looks to me like the hub has done nothing for many years:

1) Would part HSA 284 be the right replacement main axle bearings ?

2) size of bearings on 'inner dust ball ring ??

3) read somewhere that standard lithium bearing grease may be too thick and all grease should be used sparingly. So do I need a specific Sturmey archer grease or is there a more widely available grease type that is suitable

4) hub has an oil cap. 1971 brochure says use a few drops of SAE 20 Mineral Oil at least once a month. Elsewhere I've seen SAE 30 rather than SAE 20. So is there an easily available good oil ? and presumably its advisable to inspect and clean/remove at least the worst of any dried up or thick crud, rather than just add new oil ?

1) it'll work.
2) 3/16" x 24off as specified in numerous places
3) OK to use a typical ( #2) grease in the main bearings (can help with assembly). Not OK the rest of the hub.
4) Use gear oil or SFG (semi fluid grease) inside the hub

cheers