Onan L634 - need information (2024)

I aquired an Onangenset for a song awhile back but i need some parts and info on it. Tag on engine reads: McGraw-Edison
Onan L634
Model#L634 D I 10068B
Serial #B833656330
Tag on generator readsnangenset
Model#25.ODL6-15R/14C
Serial#E830660278
Service Rating- Standby
Single Phase KW17 KVA 21
Three phase KW25 KVA 33
This unit is in need of a radiator,fan and fuel tank. I managed to pick up a shop manual on E-Bay.Cummins has no info on it. Onan can't ID the numbers by says the engine is now called the Cummins A-series.

Any info and/or sources for these parts or other literature would be greatly appreciated. Thanks

Your find has a -15 Voltage Code. That means it is a Single Phase/Three
Phase, Reconnectable GenEnd, which is really GOOD, but Your DataPlate
also says that your Genend is NOT, an Extended Stack, which is why it is
deRATED, when connected in Single Phase. Oh well, you can't have
everything.

Bruce in alaska

Extended Stak is a Genend that has more IRON and Copper in it, than
the regular builds. This allows the Genend to put out the same Kw's
when wired for Single Phase, or Three Phase, generation. Your Posted
DataPlate indicates that your Genend is limited to about 2/3 the Kw
output when wired for Single Phase operation. Therefor, it is not an
Extended Stak design, which is fine, if you only need 2/3 power in
Single Phase operation, or can use Three Phase Power in your intended
application. Having a -15 Voltage Code, means that your Genend is
reconnectable in various Voltage and Phase Configurations. This is a
GOOD thing to have, and most guys wish theirs was. Extended Stak is
a BONUS, should one be lucky enough to get one built that way.

Bruce in alaska

k-oss said:

i aquired an onangenset for a song awhile back but i need some parts and info on it. Tag on engine reads: Mcgraw-edison
onan l634
model#l634 d i 10068b
serial #b833656330
tag on generator readsnangenset
model#25.odl6-15r/14c
serial#e830660278
service rating- standby
single phase kw17 kva 21
three phase kw25 kva 33
this unit is in need of a radiator,fan and fuel tank. I managed to pick up a shop manual on e-bay.cummins has no info on it. Onan can't id the numbers by says the engine is now called the cummins a-series.

Any info and/or sources for these parts or other literature would be greatly appreciated. Thanks

Click to expand...

hello. I have the same gen-set,and i am been looking for a manual for some time know.you said that you pick one on ebay.maybe you can help me.you think by any way i can have a copy off it? I will pay for the copy or for the trouble.i have no other choise. I can't find this manual any where.let me know ether way,and let me know if you need my fax# or email.thanks.
Tony

If you can not find the CORRECT parts, you may need to get creative. For a radiator, look to any liquid cooled engine of the same or larger cubic inch displacment. Fan, there are many electric fans on the market. You could use 12 Volt DC or 120 VAC. Fuel tank, You can find any number of fuel tanks in a Auto or Truck Salvage yard.

Kent

I just picked up one these as well, is this a cummins or Onan engine?
Mine says both 30 KW for both 3 phase and single phase, so i guess it's a heavier duty gen end? (the so called extended stak?) It's rating is for standby power though, or so the tag says. When I rubbed the sticker on the engine, all the numbers disappeared. Any help with getting manuals for this would be greatly appreciated, just point me in that direction. If someone here has them and can copy them it would help out.

Model-30DL-6L2879E ONAN
S/N L880186485

The reciept said 30DL6-15R Grove (I think they were the vendor who originally sold it)

Any help from the experts here is appreciated

I just replaced a radiator in one of those. It is no longer available through ONAN. I had a core radiator from a previous job and had a new core put in it.
Water pumps are still available, for $850.00. Thermostats are also still available. If you don't have an emergency need for the generator, I would have the radiator rebuilt. Same with the water pump if you can find someone to do it, if you end up needing one. Water pumps seem to be a problem with these units. I would shop for a used fan via the stak or fleabay. You might be lucky and find a pusher fan to install.
Onan does not do much to support these units anymore.
They were very good generators, but you will have a difficult time finding parts.
I try to run like hell everytime I have to work on one as I know I will have to make everything.

Mikey

To all,

BTW, the Cummins "Bulletin" number is 3810384-00.

The book Billy mentioned is still available through any Cummins distributor--you may have to tell them to look it up through "Western Graphics'--Cummins page.

I attached showing the printing price for a new reprint. I purchased a manual I needed through them once for the job, and the book was $10.50, but they socked me with $11.50 S&H!! (Western Graphics, not Cummins)

You'll have to zoom the picture once to be able to see it clearly.

eric

Fred - Bruce is right. Lots of Onan parts are expensive. Water pump for my MCCK is over $400 from Onan, same pump from the OEM is $250. Don't know about that $800 ignition coil, however.

The best answer is to either fix or rebuild the existing parts when possible, and hunt carefully when looking for new ones. Ebay and cross-references are your best friends.

With these old Onans, even though parts can be expensive, they're pretty reliable units. My MCCK lasted the first 22 years of it's life needing nothing more than seawater pump impellers, points and spark plugs (in other words, general maintenance items). This year was the first time I actually had to replace a part other than that. It got a new coolant pump last week. Unit was built in 1986.

In other words, I wouldn't worry too much about the cost of parts it doesn't need yet.