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Onan generator 7500 need stator and rotor

Kidoo
Explorer
Explorer
Hi, I need to replace the stator and rotor in my HDKAJ 7500 gen set. I took it out and found that the rotor has lost 2 magnets. The stator is also damaged and cannot be repaired, in my area anyway.

Any suggestion for repair or replace beside Onan direct for a better price? I was quoted 1200 for the stator and 621 for the rotor.

Thanks
Monaco Cayman 34 2003, Cummins 300HP
Bigfoot 2008, 10.4, F350, 2006, Diesel 6.0, Black, 4x4, long box, Air lift, Rancho 9000, Rear sway bar.
14 REPLIES 14

FIRE_UP
Explorer
Explorer
wa8yxm wrote:
Your generator assembly has two major assemblies. Motor and Generator
The generator consists of strator rotor brushes and control electroncs. You are replacign 90% of the generator portion of the assembly.


wa8yxm,
Just for your info, there are NO brushes in the rotor/stator operation in the 7.5QD units. It is proximity fit only.
Scott

On edit: Sorry, I didn't see Kidoo already stated there's no brushes.
Scott
Scott and Karla
SDFD RETIRED
2004 Itasca Horizon, 36GD Slate Blue 330 CAT
2011 GMC Sierra 1500 Ext Cab 4x4 Toad
2008 Caliente Red LVL II GL 1800 Goldwing
KI60ND

Kidoo
Explorer
Explorer
There is no brushes on my generator. There is rotor with magnet and a stator with the wire windings, and there is an inverter / computor that controls everything.
Monaco Cayman 34 2003, Cummins 300HP
Bigfoot 2008, 10.4, F350, 2006, Diesel 6.0, Black, 4x4, long box, Air lift, Rancho 9000, Rear sway bar.

wa8yxm
Explorer III
Explorer III
Your generator assembly has two major assemblies. Motor and Generator
The generator consists of strator rotor brushes and control electroncs. You are replacign 90% of the generator portion of the assembly.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times

udidwht
Explorer
Explorer
FIRE UP wrote:
udidwht wrote:
Highway robbery if you ask me. I spent years building Type-4 motors for Volkswagen's and the average cost to do a full rebuild on one ran ~$3500. But for a generator that is far simpler than a Type-4? Cost to do a rebuild on one should be no more than $500 bucks tops.


Well Partner,
You're obviously not too familiar with what we're talking about here. No one's speaking of rebuilding the engine part of the generator. What we're speaking of is, the ROTOR and the STATOR part of the gen. Those two are the major components of making electricity. The engines normally last a long, long time in these gens. It's the electrical side that has more issues. As I stated a while back, my rotor cost me right at $200 and the stator, $1,150. So, that's $1,350 invested in mine at a mere 265 hours.

And, diesel parts usually cost more than counter-part gas parts anyways. I had to replace a head gasket and lower thermostat housing when I did my rotor and stator, that was right at $105.00. So, yep, these things cost for sure.
Scott


Even more to my point. If it's just an electrical item than even cheaper than a rebuild. Much cheaper.
1994 Fleetwood Southwind Storm
P-30 chassis 7.4L 454 TBI 58,301 miles and counting....(as of 06/08/19)
VIN# 1GBJP37N4R3314754
Flight System Generator man 360 (PM me)

FIRE_UP
Explorer
Explorer
udidwht wrote:
Highway robbery if you ask me. I spent years building Type-4 motors for Volkswagen's and the average cost to do a full rebuild on one ran ~$3500. But for a generator that is far simpler than a Type-4? Cost to do a rebuild on one should be no more than $500 bucks tops.


Well Partner,
You're obviously not too familiar with what we're talking about here. No one's speaking of rebuilding the engine part of the generator. What we're speaking of is, the ROTOR and the STATOR part of the gen. Those two are the major components of making electricity. The engines normally last a long, long time in these gens. It's the electrical side that has more issues. As I stated a while back, my rotor cost me right at $200 and the stator, $1,150. So, that's $1,350 invested in mine at a mere 265 hours.

And, diesel parts usually cost more than counter-part gas parts anyways. I had to replace a head gasket and lower thermostat housing when I did my rotor and stator, that was right at $105.00. So, yep, these things cost for sure.
Scott
Scott and Karla
SDFD RETIRED
2004 Itasca Horizon, 36GD Slate Blue 330 CAT
2011 GMC Sierra 1500 Ext Cab 4x4 Toad
2008 Caliente Red LVL II GL 1800 Goldwing
KI60ND

udidwht
Explorer
Explorer
Highway robbery if you ask me. I spent years building Type-4 motors for Volkswagen's and the average cost to do a full rebuild on one ran ~$3500. But for a generator that is far simpler than a Type-4? Cost to do a rebuild on one should be no more than $500 bucks tops.
1994 Fleetwood Southwind Storm
P-30 chassis 7.4L 454 TBI 58,301 miles and counting....(as of 06/08/19)
VIN# 1GBJP37N4R3314754
Flight System Generator man 360 (PM me)

Kidoo
Explorer
Explorer
Johny Walter.
The rotor is bolted to the crankshaft and the fan is bolted to the rotor, so everything turns with the engine.
The inverter assy kick in the power and as it requires more HP, the governer increase do decrease the RPM to keep up with the required power.
When the rotor throws magnets, it damages the stator and it normally fail. I think I damaged mine when I also had the gen set running on rough Mexico roads.
Monaco Cayman 34 2003, Cummins 300HP
Bigfoot 2008, 10.4, F350, 2006, Diesel 6.0, Black, 4x4, long box, Air lift, Rancho 9000, Rear sway bar.

Kidoo
Explorer
Explorer
FIRE UP wrote:
Kidoo wrote:
Hi, I need to replace the stator and rotor in my HDKAJ 7500 gen set. I took it out and found that the rotor has lost 2 magnets. The stator is also damaged and cannot be repaired, in my area anyway.

Any suggestion for repair or replace beside Onan direct for a better price? I was quoted 1200 for the stator and 621 for the rotor.

Thanks


Kidoo,
I have done just exactly what you're about go get into. I did a rather lengthy thread on it about 5 years ago or more. I have a zillion pictures of dismantling that generator, all the way down to that rotor and stator. I got real lucky on my replacement rotor. I found it on ebay. It was out of an 8KW Onan. It's the same exact rotor. I got it for $200 which, included shipping.

As for the stator, well, that's another story. I looked all over the place and finally found one for $1,150. I bit the bullet and bought it. I did the complete tear-down and install. Our gen is on a sliding tray which, makes this sort of repair CONSIDERABLY easier.

Since the loss of Photobucket, I've not be able to post any pics on here or, otherwise, I'd show you a ton of photos that might help in your process. That is, if you're the one that's gonna be doing the work. If not, no biggie. Any questions, PM me if you'd like.

Scott


I already have the gen set out, it is not on a rail, real pain, needed a motor lift. I took the rotor and stator out and now trying to find the best deal, but it seems like I will have to buy new from Onan.
Monaco Cayman 34 2003, Cummins 300HP
Bigfoot 2008, 10.4, F350, 2006, Diesel 6.0, Black, 4x4, long box, Air lift, Rancho 9000, Rear sway bar.

JohnyWalter
Explorer
Explorer
New to this site. first post:
I run my RV generator as we go down the road in hot weather. 3k hours, 12 years old. It suddenly stalled. researched the forums and concluded It had thrown off one or more magnets and jammed up the rotor/stator assembly. no fault codes. But,the Generator engine starts, runs and after the normal 30-60 seconds, tries to load up and generate A/C, but just lugs down and acts as if the rotor is stuck. Engine doesn't stop/shut down. I don't let it run long under that "loaded/lugging condition b4 I shut it off. still no codes flashing.
Inspection determines that the fan/rotor rotates smoothly, both directions, so probably not a "thrown magnet". The Inverter output has one of the two (L1/L2) wires fried, as in it looks like a cutting torch cut thru -- thus, no electrical connection for that leg. Terminal block damaged, replacement ordered.
Question: Can this condition in effect cause the generator/rotor to effectively lock up? Is there some sort of "clutch" that allows the generator to seize/lockup w/o stalling the engine? Is this the function of the governor? Isn't the rotor a direct drive off of the crank shaft? Have not determined if the rotor/fan is actually rotating when this happens, but it seems like it must be if the engine doesn't stall. If I assumed that it is rotating, why would it lug down like it's got a big load on it. when i get a new terminal block, I plan to start it and measure voltage at that point and verify rotor/fan actually rotating. can a failed Inverter (electronic control board) cause these symptoms? Thoughts/advice please?
[url]http://jonsguide.org/best-whole-house-generators/#generac-5871-guarding-series-power-generator

FIRE_UP
Explorer
Explorer
Kidoo wrote:
Hi, I need to replace the stator and rotor in my HDKAJ 7500 gen set. I took it out and found that the rotor has lost 2 magnets. The stator is also damaged and cannot be repaired, in my area anyway.

Any suggestion for repair or replace beside Onan direct for a better price? I was quoted 1200 for the stator and 621 for the rotor.

Thanks


Kidoo,
I have done just exactly what you're about go get into. I did a rather lengthy thread on it about 5 years ago or more. I have a zillion pictures of dismantling that generator, all the way down to that rotor and stator. I got real lucky on my replacement rotor. I found it on ebay. It was out of an 8KW Onan. It's the same exact rotor. I got it for $200 which, included shipping.

As for the stator, well, that's another story. I looked all over the place and finally found one for $1,150. I bit the bullet and bought it. I did the complete tear-down and install. Our gen is on a sliding tray which, makes this sort of repair CONSIDERABLY easier.

Since the loss of Photobucket, I've not be able to post any pics on here or, otherwise, I'd show you a ton of photos that might help in your process. That is, if you're the one that's gonna be doing the work. If not, no biggie. Any questions, PM me if you'd like.

Scott
Scott and Karla
SDFD RETIRED
2004 Itasca Horizon, 36GD Slate Blue 330 CAT
2011 GMC Sierra 1500 Ext Cab 4x4 Toad
2008 Caliente Red LVL II GL 1800 Goldwing
KI60ND

Twomed
Explorer
Explorer
I took my stator to two really good rewind shops and both said Onan does something special...don't remember what, but they could not guarantee it.

Lots of work if you have to pull it again, BUT you will be more experienced. 🙂
Happy Trails 🙂
06 Monaco Dynasty
07 Hummer H3
FMCA 279843

lj2654
Explorer
Explorer
I had mine done during a 1000 hour service at Cummins Onan service center. $2800 for service and stator/rotor replacement.
2001 Beaver Contessa Naples 40
2012 Cadillac Srx
retired AirForce 1979-1992

Kidoo
Explorer
Explorer
I got another price from Yakima generator, $557 free shipping for the rotor.

For the stator, there is a place where they rewind it for $750, Eurton Electric, but don't know shipping fees yet, and it is very heavy, probably need a wooden box.

There is a good difference in price, but from Onan, it is new and the did have an upgrade on both parts.
Monaco Cayman 34 2003, Cummins 300HP
Bigfoot 2008, 10.4, F350, 2006, Diesel 6.0, Black, 4x4, long box, Air lift, Rancho 9000, Rear sway bar.

Twomed
Explorer
Explorer
That's a good price, most folks have paid a lot more. I got about that number ten years ago with dealer assist on pricing. USD
Happy Trails 🙂
06 Monaco Dynasty
07 Hummer H3
FMCA 279843