Mar 79 FJ40 2F Alternator rebuild Q

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Feb 10, 2008
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Guys... I am trying to salvage ye 'ole alternator. I have managed (with help) to undo the three screws and got to the point where I need to separate the rear aluminium case from the iron core (the 'stator' with the windings & diodes). I have looked at the Alternator Rebuild already. It just says 'remove the rear, use rubber mallet' - great.

I CAN"T remove the rear half!! I have tried:

1) Freeze Release: -> useless
2) blowtorch: afraid to get it really hot as I could cook the enamel on the wires -> no joy
[Combined 1) and 2) : heat the aluminium, freeze the core ->nada]
3) soak in <insert your favourite WD40-type oily stuff here> -> nutin'
4) soak in degreaser -> nah
5) hammer on the iron core with regular (not rubber / plastic) -> nope
6) hammer everywhere with rubber mallet -> guess what...
7) vicious swearing, mean looks -> er... No.

I am afraid of hitting the rear case really hard - it could shatter as it is Al.

Any ideas please ?!?
 
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TRy bending a large paper clip more or less straight and retract the brushes via the small hole near the middle of the alt. rear housing. Then see if it comes apart.
 
OK, you have the front half of the case off, the round rotor is out, and you took the three nuts off the studs on the back of the housing so the diode bridge can come out. Is that all correct? If so then the only thing holding the stator to the rear housing is corrosion. The pic shows where the iron and aluminum will fuse together. The circled area (where the long screws go through the case) indicates where you can insert a small screwdriver to try and pry it a bit.

I did not have too much problem with the F alternator but the 2F was harder to get apart for some reason. Maybe tighter tolerances in the case?
Alternator1.webp
 
Assuming it is not being held together by any missed/hidden fasteners...
Squirt penetrant on the parting line.
Warm up the alum rear case w/ a propane torch. AL has a much higher coefficient of thermal expansion than the iron core, so even if the iron takes some of the heat, the AL case will be expanding more.
Hold the iron core and hit the case down off the core. Keep hitting. It will either give way, or the case will break.

Case comes off- replace brushes & bearings, reassemble.

Case breaks- order reman from FLAPS for $69, exchange broken core.
 
OK, you have the front half of the case off, the round rotor is out, and you took the three nuts off the studs on the back of the housing so the diode bridge can come out. Is that all correct? If so then the only thing holding the stator to the rear housing is corrosion. The pic shows where the iron and aluminum will fuse together. The circled area (where the long screws go through the case) indicates where you can insert a small screwdriver to try and pry it a bit.

I did not have too much problem with the F alternator but the 2F was harder to get apart for some reason. Maybe tighter tolerances in the case?

Yes that is exactly the stage I am at...all screaws are out.

Unfort I do not have those indents on the 2F alternator to insert a screwdriver ... will keep trying I guess.. although I am in Australia and i do not know if i will even be able to get the brushes as they are kinda short now... but the remanuf alternators were 45A early type, mine is 50A late type (no plate holding the front bearing)
 
Assuming it is not being held together by any missed/hidden fasteners...
Squirt penetrant on the parting line.
Warm up the alum rear case w/ a propane torch. AL has a much higher coefficient of thermal expansion than the iron core, so even if the iron takes some of the heat, the AL case will be expanding more.
Hold the iron core and hit the case down off the core. Keep hitting. It will either give way, or the case will break.

Case comes off- replace brushes & bearings, reassemble.

Case breaks- order reman from FLAPS for $69, exchange broken core.

Haha... I am in Aust, reman is 45A early type...I'd like to stick with the 50A ... Yes I have heated the thing exactly 'cause I thought Al and iron will behave differently... maybe I heat it up some more...
and yes i have squirted all kinds of things inside and outside the case, including the famous Freeze Release which until now has not helped me anywhere :-(

Pffff.... back to it...Thank you

UPDATE: IT CAME OFF!!

Pic223.jpg


Man's best friends:

Pic221.jpg


Now look at the brush size :-((

Pic224.jpg


Thanks...
 
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