Community Forums

Stan&Jacquie · 12-03-2019, 09:35 PM

Someone suggested that Onan belts on the QuietDiesels are very hearty and usually can go beyond the recommended 1000hr replacement time.

If you have thrown a belt, please specify your model genset, it's age, and how many hours were on the belt.

If you have exceeded the 1000hr interval, let us know when you changed it (genset hrs) or, if it is still going strong, it's age and the no of hrs on it. Thanks!

USMCRET · 12-04-2019, 03:45 AM

Haven’t thrown a belt, but took my 7.5 in for 1000 hr maintenance yesterday. The genset has 1250 hr. Estimated cost $1800-$2000. Genset has to be dropped out of MH.

We got electrically stranded last winter 2000 miles from home when the rotor decided to throw magnets and take out the stator and inverter in the process. That sucked beyond description. While nothing could have prevented that, I’m not taking chances with preventive maintenance.

hypoxia · 12-04-2019, 05:38 AM

Quote:

Originally Posted by Stan&Jacquie

If you have exceeded the 1000hr interval, let us know when you changed it (genset hrs) or, if it is still going strong, it's age and the no of hrs on it. Thanks!

At 1500 hours I changed the belt. The old one looked great. I also changed the water pump, all coolant hoses, thermostat and coolant temperature sender. Everything I removed looked good. I prefer preventative maintenance in my shop to on the road repairs.

Rusty Kramer · 12-04-2019, 06:46 AM

Stan, when I talked to Cummins/onan at a trade show last year I asked them, what should be done for maintenance (other than oils) on my almost 20 year old 7500?

One of the first things mentioned was the fan belt. Not too hard to replace, low cost and if it breaks will shut the gen down due to heat.

Gary RVRoamer · 12-04-2019, 09:54 AM

Quote:

One of the first things mentioned was the fan belt. Not too hard to replace, low cost and if it breaks will shut the gen down due to heat.

LOL! Spoken by a man who obviously has never attempted to get at an Onan 7500 coolant V-belt in a motorhome installation. I'll bet he was a marketing guy. Or maybe a Onan factory tech who only works on Onans in his well-equipped shop.

If it was easy to do, we wouldn't be having this conversation.

deandec · 12-04-2019, 10:00 AM

Quote:

Originally Posted by Gary RVRoamer

LOL! Spoken by a man who obviously has never attempted to get at an Onan 7500 coolant V-belt in a motorhome installation. I'll bet he was a marketing guy. Or maybe a Onan factory tech who only works on Onans in his well-equipped shop.

If it was easy to do, we wouldn't be having this conversation.

Not a difficult problem on my old PowerTech 7k. Did it myself in about 30 minutes and I am no mechanic.

Spk64 · 12-04-2019, 10:13 AM

I did not throw a belt but when I did the change which was just over 1,000 hours. The belt had many cracks and was stretched. There is not an adjustment for tension so when the belt stretches the belt becomes loose.
Glad I did the change vs waiting till on the road and having a problem.

RichKimball · 12-04-2019, 10:27 AM

Now that I say this...mine will break. Mine is not on a slide out and not looking forward to the day.

Onan 8KQD. 2008 with 3,900hours. Yeah...that many hours.

Normal oil change every 150 and air/fuel every 3 years.

Rusty Kramer · 12-04-2019, 12:38 PM

Quote:

Originally Posted by Gary RVRoamer

LOL! Spoken by a man who obviously has never attempted to get at an Onan 7500 coolant V-belt in a motorhome installation. I'll bet he was a marketing guy. Or maybe a Onan factory tech who only works on Onans in his well-equipped shop.

If it was easy to do, we wouldn't be having this conversation.

Gary, I guess Depends on your past mechanical experience, and projects as to where this will fall on the difficulty scale.
I am not saying I am looking forward to it myself or even that I am competent, but I have enough experience with "mechanical stuff" so I guess this one does not sound too scary for me. But I will find out I am sure.

Ivylog · 12-04-2019, 01:42 PM

Friends 12K in a 02 Sig belt broke (not sure of the hours). Fortunately it’s in a slide so it’s possible to get behind it. Took about 3 hours to change it...lots of screws holding the top and back on that are not easy to get to.

Dav L · 12-04-2019, 02:29 PM

I bet a right angle drill / screwdriver electric would help get to a lot of those hard screws. I use a DeWalt 20v Max with short #2 phillips bit. Don't have to use it much, but it's wonderful when it's needed.

Samdon · 12-05-2019, 02:11 PM

I had to replace the belt on my 12.5QD last year at around 750 hours. It would run for a period, temp rising, until shutting down for safety. I assumed the belt had broken or been thrown so I ran an inspection camera in there and the belt looked perfect......buuuuuut it wasn't. The inner surface was glazed and slick as glass. It turned the fan but only very slowly.

Compounding the issue in my case was the fact that some 1st gen 12.5 Onans used an Isuzu engine. Most have Kubota mills. Even Cummins Power assumed that and sold me the direct drive retrofit kit. Needless to say; the retrofit does not apply to units with an Isuzu engine. They very kindly refunded my money and apologized but were sadly unable to make good on most of a day lost. I was then sold an appliance belt which hopefully takes me another 750 hours. Simple replacement but for the million and one fasteners that must be removed for access.

NHRA225 · 12-05-2019, 03:21 PM

I have serviced a number of the Qd Generators over the years including replacing the Fragmented Rotors and Stators and Shredded Belts.
I would strongly suggest that you follow the Onan recommended service and maintenance schedules in your manuals.
I've seen belts ready to fall off @ 700 hrs and Belts that looked good @ 1500 hrs of service. Excessive Heat is the cause of belt failure.
For those that are tucked up in the front and not on a Slide out - you have my sympathy as some require major surgery to remove costing up to $800 to $1200 for a $15 dollar belt.

Roger G · 12-05-2019, 06:40 PM

It looks daunting but pulling the generator is a really simple project. The only specialized piece of equipment required is a “cherry picker” engine lift, less than $200 at Harbor Freight. I can have a diesel generator sitting out and on the ground in 30 minutes by my self. Requires an additional person to put it back in, the lift point isn’t exactly in the center of the weight.