Need help with Onan alternator

[KyleR]

Hi all,

I have a 10kw Onan generator, model MDKWB Series E, and the alternator has seized - again!

It happened the first time back on 11/23/23 and I took it to Holt Generator Shop in Jacksonville,FL and they replaced all three bearings and all seemed good, until today. Seized again, but now I'm in Key West and there are NO alternator shops here. I've called seven shops and no one works on these things.

An OEM one looks like it is running $600+, which just seems ridiculous to me. So, two questions:

1. Has anyone replaced their alternator with a comparable aftermarket one - and been happy with it? The model number for my current alternator is 185-5431 and I'm looking for a like-for-like drop-in as I don't have the ability to change/alter mounting brackets/pulleys/etc.

2. Can anyone recommend someone in the Key West/Marathon areas that has the ability to work on these, including replacing the bearings?

I'm going to disassemble it when everything cools down and if I find out it is something else I'll post back. But for now, it definitely looks like a bearing issue.

Thanks in advance!!
Kyle

[Viper]

I would take it to someone that specializes in rebuilding starters, alternators, etc., even some shops that work on mostly automotive units deal with marine ones also. Doesn't have to be a generator shop, so there may be more options to you than you think.

I would also check the mounting to ensure everything is aligned properly. If it's belt driven, make sure the tension is to spec. You should also ensure it's not running too hot for some reason.

[Midnightsun]

I only have experience from way back when I needed rebuild a Mercruiser alternator. Found out from the local automotive rebuild place that marine units differ really by only have a screen installed (flame arrestor). Point is any automotive shop that does alternators can rebuild a marine alternator. Being you have a diesel setup, I believe the flame arrestor part is not even required.

[bud37]

QR_BBPOST Found out from the local automotive rebuild place that marine units differ really by only have a screen installed (flame arrestor)

Actually there are a few things, port for the fuel return from a bad fuel pump and the bowl vent tubes feed back to the venturis.

Anyway , to add, have a check around small engine/equipment/tractor dealers as these engines are just tractor, big mower engines....maybe someone there can put you on to a rebuilder. Worth a shot.......good luck.

[Midnightsun]

Oppps, corrected my post as I meant to write alternator not carb. Only saw the mistake after you referred to fuel return.

[KyleR]

Thanks everyone. The problem is finding an alternator/starter shop in Key West. This place is filled with boats and marinas - but not a lot of shops that work on them. At least not for the issue I have. And I asked each one I called for a recommendation for an alternator shop and the answer was a unanimous "try Miami"....

Anyway, I found a place in Homestead, FL called Leon's Alternator & Starter who said he probably could help me. It's a 3 hour drive so I've gotta figure out a car rental tomorrow. Neither the Enterprise or Avis car rental places down here will come me up to go back to their store to do the paperwork, so gotta figure out that piece of the puzzle too!

I wish OEM replacements weren't so ridiculously priced!!

I'm telling you, Key West is not as boater friendly as people make it out to be!! Oh well, thanks again for all the suggestions. I'm attaching a pic of the bad bearing just for fun.

[Alanna Mo Cree]

Did you try these folks? https://mobilemarinekeywest.com/

I don't have first hand experience, but follow their Youtube channel. Seem like good people from the videos and they have a 4.8 star rating on 87 Google reviews.

[KyleR]

Did you try these folks? https://mobilemarinekeywest.com/

Thanks Charlie, I did not find them in my searches. I'll give them a call tomorrow and see if they can help. Thanks again!

[tomschauer]

Oh no! stuck in Key West, that must be terrible!
If the bearings seized after only a few months, either they didn't actually replace them, which is unfortunately possible, or they used the wrong bearings, or your alternator is getting hot enough to cook the grease out of them.
Looking at the pic you posted, the shaft is way smaller than the inner bearing race, or the shaft has worn to the point of no return. If that is the case, you may need to bite the bullet and get a new alternator.
Good luck!

[KyleR]

Thanks again for all the replies. I ended up renting a car and drove to Leon's Alternator and Starter in Homestead, FL who replaced all three bearings for only $80. Seemed pretty reasonable to me, plus it was the same price I paid the last time so I felt it was fair. Plus he squeezed me in ahead of other customers and got me in and out in just a couple of hours! Couldn't ask for better customer service!! We'll see how these hold up!