My generator stopped charging today. Appears the bearing got really stiff and the belt was slipping. Working on getting that solved quickly. But, for longer term, does anyone know of anyone that can overhaul an old generator? Or does someone have a generator that was working when removed that perhaps still has some life left in it?

I am NOT going to swap to an alternator until I have to, for a variety of reasons.

Not sure about aviation-specific repair options, but I have used Haines Auto Electric in twin falls for similar overhauls. Might just need to tell them it’s for a boat.

PM sent

Husky Auto Electric in Boise had done stuff for me in the past. No need to tell them it's from a boat, he knows what it is and doesn't care.

Do you trust your mechanical abilities enough to do it yourself? Pretty easy to repair according to a 'friend'.

I'm guessing its a Delco-Remy? Parts are (were) easy to find. I may have an old one stashed in y hangar, but I think it's only a 35 amp version. No longer have any planes that use a generator.

I'm with you on sticking with a generator, my 53 has a 35A gen & I have no plans to "upgrade".

I'm pretty sure at least one of the accessory outfits still overhauls generators--
sometimes they overhaul yours (long-ish wait), sometimes they just do an exchange for one they have ready.
Maybe check the aircraft spruce catalog & see if they list them.

FWIW my small town has an auto-electric shop which has worked on my airplane stuff.
The owner is an old pilot, so I don't have to pull that "it's for a tractor" BS with him.

Thanks for all the replies.

I think I can get mine operational until I acquire one that I can overhaul. Looks like the bearings got really stiff and the belt started slipping. Just spraying some penetrating oil on the rear bearing made it spin much easier. But it seems the shaft is stuck in the bearing, so I can't get the end cap off yet.

I've had good luck with old Delco Remy repair parts from Niagra Air Parts, you might check with them for bearings, brushes etc.

I know the old 172 manual had information on repairing the generator and starter, the AMM would be a good place to start for information on a Cessna of this vintage.

StillLearning wrote: ...does someone have a generator that was working when removed that perhaps still has some life left in it?....

Since everyone favors alternators nowadays, I'm surprised that no one has spoken up saying they have one left over after an "upgrade".

One was offered, but I have not actually had any communications since.

I bought new old stock brushes on ebay, the bearings are a standard bearing in stock, I just wish I still had my lathe to turn the armature to clean it up.

Aerotech is building me an overhauled generator, will be here in two weeks. But, I'd still like to have a spare sitting here.

I flew 40 minutes with no generator yesterday, running the JPI 830 I had 12.6 volts. After I got halfway back I turned on the radio and audio panel, still had 12.5 volts.

What I found most interesting with no power to the G5's, is that the HSI is gone altogether no information on the screen. The attitude G5 was working, but useless. The attitude indicator showed about a 5 degree right bank when level, I banked to get the attitude indicator to read level just to make sure it wasn't my imagination, it wasn't. I still had altimeter, vsi, and airspeed on the one G5. Battery backup sounds great, but if it won't run the GMU11, or the GAD 29, its kind of worthless.

All this has got me thinking about the generator breaker, its 73 years old and a non-pullable breaker. If I want to remove the generator from the system in flight the only thing I can do is turn off the master, but then I obviously can't use the battery power remaining. I'm thinking I want a pullable breaker, boy are those expensive! I haven't looked at the wiring diagram yet to see if my understanding is correct, will do that today.

Not sure if he's still active, his sign looks pretty faded, but Glenn Nagel has/had a machine shop there on 93 S

I just want to make sure i'm tracking the reason for generator preference: is it so you can make output without a field current from a battery? I can appreciate that. What current output is your generator?

Not arguing, just curious.

My understanding is that alternators are better at most of the things we ask them to do. They are lighter, provide current at lower RPM, and are smaller. They dont however self provide power if you have a completely dead battery. That is why people would want to have some sort of 12 or 24v backup jump to get the alternator online if they have a dead battery. A generator doesnt need this.

I want to stay with the generator for a couple reasons. Reliability is one, the other is the ability to produce electricity without battery power. Cost is not much of a factor, but it is there. A hartzell alternator conversion is roughly $2500, a friend has installed several of them. I am told that nearly everyone of them has a cracked bracket within a year. I have also read reviews on Spruce from people that were not happy with them. I have heard of the alternators not lasting very long as well.

My generator is 35 amp, the 50 was optional. I did an electrical load analysis when I installed my new panel, the 35 amp generator met the 85% requirement for essential equipment. I have nearly 1000hrs on my 180, this is the first breakdown in that time (other than a couple of worn out cylinders). I suspect the generator was last overhauled 30 years ago or more, that's not too bad. I don't need the higher output of an alternator, and I am old school. I like simple.

StillLearning wrote:A hartzell alternator conversion is roughly $2500

Ouch!!!

Plus installation.

StillLearning wrote:One was offered, but I have not actually had any communications since.

I bought new old stock brushes on ebay, the bearings are a standard bearing in stock, I just wish I still had my lathe to turn the armature to clean it up.

Aerotech is building me an overhauled generator, will be here in two weeks. But, I'd still like to have a spare sitting here.

I flew 40 minutes with no generator yesterday, running the JPI 830 I had 12.6 volts. After I got halfway back I turned on the radio and audio panel, still had 12.5 volts.

What I found most interesting with no power to the G5's, is that the HSI is gone altogether no information on the screen. The attitude G5 was working, but useless. The attitude indicator showed about a 5 degree right bank when level, I banked to get the attitude indicator to read level just to make sure it wasn't my imagination, it wasn't. I still had altimeter, vsi, and airspeed on the one G5. Battery backup sounds great, but if it won't run the GMU11, or the GAD 29, its kind of worthless.

All this has got me thinking about the generator breaker, its 73 years old and a non-pullable breaker. If I want to remove the generator from the system in flight the only thing I can do is turn off the master, but then I obviously can't use the battery power remaining. I'm thinking I want a pullable breaker, boy are those expensive! I haven't looked at the wiring diagram yet to see if my understanding is correct, will do that today.

Should be easy to add a switch to control the generator output, most older airplanes have one. A guarded switch on the panel looks cool too.

Zzz wrote: "I just want to make sure i'm tracking the reason for generator preference: is it so you can make output without a field current from a battery? I can appreciate that. What current output is your generator? Not arguing, just curious.

I'm with Still Learning on every point.
I'm not convinced an alternator is any better, and I'm cheap--
I don't want to spend a couple grand "just because".
I have a 35A generator, it is suffcient for my plane's electrical needs & has been for over 70 years now.
Electrical requirements are even lower nowadays, with solid state radios & LED lighting.
FWIW I have a 50A generator as a spare for if & when my 35A gives up,
I got it from a friend when he "upgraded" to an alternator "because they're better".

I don't think the available alternators are (much) lighter than my 16 pound generator.
I don't understand why all the alternator conversions for the 6-cylinder continentals are 60 or 70A,
when as I pointed out our electrical needs are much lower now.
I might be interested if they were in fact significantly smaller & lighter.

I'd like to get rid of the belt-drive aspect, so in reality,
the only alternator I'd be interested in would be a little one, 25-35A,
that can mount to the now un-used vacuum pump pad.
They make them, unfortunately:
1) they're not STC'd, and
2) they are too long to fit between the accessory case & the firewall.

If you've not already sourced all the parts good chance a vintage tractor supplier can get bearings/brushes too. I've got an old 6V generator I'd happily let someone pilfer from, but it's barely worth picking up from my pile of boat anchors let alone shipping.
I've worked on both, and no reason a generator can't be reliable. Knock on wood, my feeling is if I'm dead flat on a battery to where I can't flash an alternator field I've got bigger problems.

Main reasons to go alternator:
- they are more reliable - slip rings instead of commutator makes a difference (I've got an old commutator mica undercutting attachment for the lathe I'd sell if someone's nuts enough to buy it)
- likely on the cheaper end of $/lb savings. I mentioned my old generator is with the boat anchors right?

True though, I don't need a 70A alternator in the plane. The only subwoofers I carry are small dogs.
I too with the B&C units were STCd, and they'd make one no longer than the Vac pump so they'd fit all installs.

brushes are easy, I found 6 on ebay for $20 shipped
bearings are readily available though expensive at $140 for the pair shipped
I had the armature trued up on a lathe for $15

Shipping on anything these days is ridiculous, shipping the core back would probably cost about half the value of the core. I am keeping my core, putting it back together for a spare. The core charge is $175, if I sent it back I'd probably net about $100 out of it at best. Add in the bearings, brushes, and lathe work and I'll have a net $275 for a good spare.

I'd love to put in a little alternator that runs off the back of the engine, maybe I should ask the DER working on my Bendix injection approval if he can get it done.

Alternators are obviously much more modern, but that doesn't necessarily make them better. I doubt an alternator installed now will still be in an airplane with having been overhauled once in 73 years.