Generator blues

W

WQ59B

Member
This should be the last component to deal with (HA!)

'40 COE with '46-48 59AB motor. All stock spec, still 6V pos ground.

On 2nd trip down the road (1.2 miles), truck starts, runs & drives well- no complaints. Back in the driveway after that 1.2 miles and it suddenly starts doing the same thing it did the last time I ran it- a escalating shrill squeak from the generator. It's been out & apart & fully cleaned, and the rear bushing was inspected and seemed fine. Oil wick/well examined, and I even drilled a hole in the bottom of the rear bushing, not quite seeing how the oil was supposed to reliably go thru that 'oil-lite' bushing (can these get glazed?). If I drip some oil into the oil port, it shuts up.... for a bit, then starts again, like within 2 minutes of running.

I have the dual pulley/ fan-attached generator, and there's no front oil port. I am 100% sure it's coming from the generator. In that the battery seems to just sit at 5.9V even after that drive (new polarized VR), and having no diagnosis from the local since 1946 generator shop (who said he never heard a generator squeal), I was pondering just getting a new generator.

Any opinions/guidance? If the batt (new Optima) was where it should be, like 6.x V, I would replace both the bushing & the front bearing... but I'm willing to 'do it once & do it right'... if I only knew what that was.

If I get another generator, is my fan/dual pulley something I need to make sure the new one will mount OK?
 
The bushing must be an oilite bushing. That is a pressed grainy
material that allows the oil to saturate in it. These bushings need
to reamed with a very sharp reamer so the material is not smeared
which closes the pours. The clearance is VERY important. If it is a
.500 shaft it should be reamed with a .505 to .507 reamer. Oil from
the bushing forms an oil film which the shaft runs on. The shaft
never touches the bushing. Properly fitted and oiled a shaft or bushing
very rarely fails. You want engine oil to lube the bushing not a very
thin oil. G.M.
 
Don't pull anything to bits until you are sure ,Remove the belt then test drive it ,a few blocks wont hurt. set up a tempery belt around the pumps ,cut a old belt and thread some wire through to join it ,Ted
 
Tried to mic the rear bushing but was not getting consistent readings- can try again- thanks for the specs. Bushing doesn't look like it has any visible 'pores' (it's certainly not like a Carter AFB sintered bronze fuel filter). Then again- all the repro bushing pics look the same as mine.

The truck hasn't driven but 2 trips so far, but it's been started 50 or 60 times and ran for various short intervals with never any noise previously. But being a COE, with the doghouse out I can see the commutator spin to a quick stop which perfectly matched the squeal dying down.

But if you look at the generator 'oiling system' with the oil wick & well, it seems shaky at best... that the spinning shaft is going to pull oil up the wick and THRU the porous bearing.
 
I can see you are clear were the noise coming from ,I think the wick should be touching the shaft /need to look at the book ,Ted
 
No; bushing fills the space in the rear cover, the oil wick presses against the outside of the bushing. I would've also thought it should touch the shaft directly... like there should be a hole large enough in the bottom for the wick to go thru... but all repro bushings have no hole. Am I missing something- are replacements supposed to be drilled? The hole I put in is smaller than the wick but I wasn't sure a really large one would be OK...
 
WQ59B said:
No; bushing fills the space in the rear cover, the oil wick presses against the outside of the bushing. I would've also thought it should touch the shaft directly... like there should be a hole large enough in the bottom for the wick to go thru... but all repro bushings have no hole. Am I missing something- are replacements supposed to be drilled? The hole I put in is smaller than the wick but I wasn't sure a really large one would be OK...
Click to expand...

I'm not familiar With the oiling set up other than you put oil in the
Gits cap on the top. I don't see how oil would wick up unless the
friction heat has something to do with it. I would expect the wick
to be on top so oil saturates the bushing. On the water pumps
there is a open area around the bushing where the heavy oil or
melted grease saturates the bushings. In thousands of water pumps
I have seen very few dry from lack of lubrication. G.M.
 
This is similar to mine:
http://www.macsautoparts.com/assets/macs/images/size/160x160/sku/64-14595.jpg
an oil port to the north, the shaft & bushing central, and an 'oil well' & wick below. The oil you dribble in the oil port runs around the rear open end of the bushing... some goes around the shaft, much of it drops down behind & into the well. There's a tiny bleed hole that keeps the well no more than 80% full. The oil wick pressed upward against the OUTSIDE of the bushing. Somehow, this is supposed to draw oil up thru the bronze and around the shaft but I don't readily see how. I don't think it's due to heat; heat comes from friction and properly oiled- there shouldn't be any of consequence.
 
On reading generator servicing manual the front bush on some are lubed by vapour, maybe the same goes for the rear one .When everything gets hot you get vapour coming up the hole ,ted
 
Theory: are you supposed to drill a hole in the rear bushing large enough for the wick to push thru & ride on the shaft? It's the only scenario that makes logical sense to me. All the repro bushing are hole-less because 1. it's cheaper to produce, and 2. maybe different generators have different size wicks, and 3. it's easier to install the bushing THEN drill it for easier alignment.

Anyone ever seen any info talking about drilling the bushing?
 
The sintered bushings were invented in 1930 by Chrysler Corp. Maybe Ford used plain bronze and needed the oil hole. More modern equipment using sintered bushings many times don't bother with an oiling port so I think that the replacements today don't need a hole, 'though it probably wouldn't hurt anything to have a small one if it made you feel better.
 
The NOS generator end plates come with the bushing installed and there is no hole in the bushing! The bushing does not extend all the way to the rear of the cover there is a small gap of approximately 0.030 to 0.040" Maybe your end plate was not made properly or the bushing was installed too deep and there is no gap. I looked at two end plates as shown in your Mac's catalog and yes both have the small hole it is just to the bottom of the bulge for the rear bushing. You could temporally block the hole and add more oil allow some time for the wick to absorb the oil (maybe overnight) and then unblock the hole and see how this works. The oil on the wick should act much like putting a drop of water on a paper towel The water is absorbed by the paper towel but the area of absorption is much larger that the original drop. If you were to overfill the wick and the well it sits in, the worst that can happen is the rotating armature will throw it off until there is a stable amount of oil. You could add some paper around the rear of the generator to catch the excess oil, so it does not get over the engine or the engine cover.
 
• I reused the wick that was in mine- it was saturated & sound.
• the bushing is not too deep, oil dropped into the oil port definitely gets into the oil well and weeps out the bleed hole when full. Last time I pulled it apart the shaft was liberally oily, plus there was a smear of oil at the bottom inside of the rear cover; it was making it's way out the front of the bushing.

• The squealing noise quickly rises in pitch until no vehicle owner would dream of letting it run 5 more seconds. But both times it did this it did a mile+ of driving before squealing. All thos other times it was started and ran for a few minutes to 10 minutes, it never made a peep.

I'd prefer not to have to buy a new generator if not necessary.

OH... BY THE WAY, I am not seeing my generator offered repro- will the dual pulley & fan mount on any period Ford generator, or does mine have a longer shaft to mount the extra bits?
 
The rear cover usually has a Ford part number embossed inside. You would have to take it apart. You can check with Fred at Southside Obsolete and see if he has a new back cover.
 
WQ59B said:
But being a COE, with the doghouse out I can see the commutator spin to a quick stop which perfectly matched the squeal dying down.
Click to expand...

If the bushing seized enough to stop the generator's rotation as described; it seems strange that it was still oily (vs dry and damaged) when you later inspected it. In my experience, generators, alternators, pumps, etc that mechanically quit turning, stay that way.

Sure it isn't electrical load and belt slippage, bad regulator, etc.
 
A battery voltage of under 6v is worrysome. Excessive electrical load on the generator would cause belt squeel and/or generator complaint.

I recommend you remove all electrical connections from the generator (taping the wires) and do your 1.2 mile trek. The generator will experience the same number of rotations in the same heat conditions. See if it complains with noise then report back.
 
So the generator armature stops turning when the noise is occurring ??? Slipping belts or more likely the generator pulley is not tight on the armature shaft. Nut on armature shaft not tight or if the armature shaft has a woodruff keyway, is the key missing. Need to pull generator apart and check that. Regards, Kevin.
 
No no; when I hear the squeal, I hit the ignition toggle, shutting the truck off. This is maybe a 4 second time span- I'm not eager to see how loud it'll keep getting or what is going to break. If I put oil in the rear port, it's quiet... for about 1-2 mins of idling, then starts again. <-- This procedure has happened twice so far.

Belts are NOT slipping- I have dual belts & the pulleys have enough 'tooth' on them it would be pretty much impossible. I've had the motor turning what I would guess is over 2500 RPM and there was no squeal (VR testing).

Is the front bearing getting warm via engine heat, and then it starts to squeal?

Paul- I'd like to try your test, but know that in order to pull the fan-mount generator out of a COE, you have to drain the coolant and remove one pipe. I'm on my 3rd go-round of doing that, it's a bit tiresome- would like to nail this and call it done.

Right now the collnat is drained, the pipe is off & the gen is ready to come out. Again. Thinking I am going to replace both bearings and button it all back up.

Not sure why I can't get the battery over 5.9V... unless it would take more than a 1.2 mile trip to get some juice in it (before the road trip it was 5.9). Last time we checked the output, after a new polarized VR, we got it up to 6.25V by revving the engine steadily higher... but specs say 7.1-7.4. Also, I have a cut-off switch, when the truck is off the battery circuit gets turned off.
 
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Think I would concentrate on the generator output problem. Something is going on there and may be contributing to your squeal issue.
 
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