Onan 7.5 Kw Genset Access

[RC2018]

I have a 2003 Diplomat with a stationary Onan 7.5 Kw genset. To service the unit (I don't mean changing oil and filters) I mean changing belts and hoses, it will have to be removed from the nice pocket Monaco stuffed it into when it was manufactured. Does any one know if a slide out tray can be added to my Dip? Does anybody know who manufactured the slide out for gensets that are on a slide?

Thanks in Advance

[klcdenver]

You might try a salvage yard and find what you would need.

[Dwight Lindsey]

Randy:

When my 8K Onan failed due to a disintegrating water pump belt (NOT a fan belt, the fan is direct drive), I had to pull it out of the motorhome.  Mine is also bolted in and not on a slide.  I also have thought about adding a slideout for the generator, but after having removed it once, I'm no longer feeling the need.

It was easier than I expected.  While not trivial, in retrospect it wasn't that big a job.

Here's what I did:

First, I soaked the bolts holding the generator in with penetrating oils.  I let that sit a few days.

Then removed the generator door.

Then I unhooked the diesel fuel line and fuel return. 

Then I unhooked the DC connections that are near the fuel lines. 

Then I unhooked the AC connections at the front of the generator.

Then I removed the bolts.  I broke two of them . . . after removing the generator I had to drill them out, later which was the most difficult part of the job.

Then I used a rented manual Material Lift to lift and remove the generator.  I put a strap around the back of the generator to the material lift when I pulled it out.

Then I removed the sheet metal covers top, side and back.

Changed the belt.

Reversed the procedure.

While this all occurred over several days, I estimate the actual work hours at 5 hours.  I only asked for help from my son for a few minutes when re-installing the generator, it helped to get the bolt holes lined up.

Installing a generator slide would mean sourcing a slide (I did find one at a junk yard), removing the generator, welding the slide in place, attaching the generator door to the slide, arranging the exhaust pipe to follow the slide . . . 

When needed, I'll just pull the generator out again as described above.

Dwight

 

[Verde_Windsor]

Oh..h that generator slide.... I can tell you how much I love it... 

First off all - I have all (or most) receipts from new, from previous owners. I know for a fact they had a problems with it. I have a problems with it.

The whole rack-n-slide is nothing special. Any DIY backyard tinkerer with welder can make one.

The pump and hoses situation is.. to simply say it ...not great. In 2023 I can assemble better system with store shelf parts. Took me a whole day, taking it apart and cleaning and blowing and replacing fluid and trying to flex my brain back into 90's to understand it. It still work intermittent. It cheaper to crawl under, undo pin and slide out by generator by hand.

I might rebuild system one day. But then, how often do you need to open it? And it rattle on start up or on big bumps. Just the nature of it. 

So to simplify what I saying - keep it simple. Less to fix, less to worry.

And one more thing, if slide is on the front side of the bus - it have to have safety pin! To prevent it flying out forward, during emergency activities  😉

[Guest Ray Davis]

22 hours ago, Verde_Windsor said:

And one more thing, if slide is on the front side of the bus - it have to have safety pin! To prevent it flying out forward, during emergency activities  😉

My gen slide is probably the same as yours, but I'm not aware of a safety pin.  Where should I look, and what does it look like?

Would it be an automatic device?  Surely you don't have to get out and pull it manually. 

[Tom Cherry]

3 hours ago, Ray Davis said:

My gen slide is probably the same as yours, but I'm not aware of a safety pin.  Where should I look, and what does it look like?

Would it be an automatic device?  Surely you don't have to get out and pull it manually. 

All I can provide is the consensus of the ages from folks with “don’t work” genny slides and two were our founders and not inclined to mega repairs.  First is the control circuitry.  There is a great layout on the original and Monaco changed little.  There is a switch as well as a “safety” switch. As long as you have full 12 VDC and the Pump & Motor are working, the the conventional advice was to “take apart” and rebuild the hydraulic valves….periodically.  Monaco supposedly used Teflon tape, way too much….and the excess or the tape that was “inside” the fitting would eventually break loose….contaminating the fluid.  Flush the system and new fluid and drive on until another shard(s) broke loose…

Thats the 30K macro view from most of our posters on genny slide fixes.

[genemenne]

For what it's worth, I have a 2004 Monaco Knight with a non-sliding 7.5kw Onan generator.  When I had some work done by Cummins on the generator, they lifted up the whole motor home and then put a small manual lift under the generator and removed it from underneath the motor home very quickly.

Gene

[Verde_Windsor]

9 hours ago, Ray Davis said:

My gen slide is probably the same as yours, but I'm not aware of a safety pin.  Where should I look, and what does it look like?

Would it be an automatic device?  Surely you don't have to get out and pull it manually. 

Yes and yes. There is one way valve in the circuit, or sometimes called check valve. Lets fluid go one way and won't let it go back.

 

[RC2018]

I agree with keeping it simple. Maybe I'm over thinking the challenge of sliding the genset out of the motorhome. The genset cover is hinged to a 2" square aluminum tube that seem to be fiber glassed to the front cap, which makes removing the alum. tube a big project in its self. If the tube was out of the way, a fork lift and strap would do the trick.

 

Thanks for the comments

[Guest Ray Davis]

On 8/21/2023 at 9:19 PM, Verde_Windsor said:

Yes and yes. There is one way valve in the circuit, or sometimes called check valve. Lets fluid go one way and won't let it go back.

 

Thanks, got it

[JustaRamble]

On 8/20/2023 at 11:25 AM, Dwight Lindsey said:

Randy:

When my 8K Onan failed due to a disintegrating water pump belt (NOT a fan belt, the fan is direct drive), I had to pull it out of the motorhome.  Mine is also bolted in and not on a slide.  I also have thought about adding a slideout for the generator, but after having removed it once, I'm no longer feeling the need.

It was easier than I expected.  While not trivial, in retrospect it wasn't that big a job.

Here's what I did:

First, I soaked the bolts holding the generator in with penetrating oils.  I let that sit a few days.

Then removed the generator door.

Then I unhooked the diesel fuel line and fuel return. 

Then I unhooked the DC connections that are near the fuel lines. 

Then I unhooked the AC connections at the front of the generator.

Then I removed the bolts.  I broke two of them . . . after removing the generator I had to drill them out, later which was the most difficult part of the job.

Then I used a rented manual Material Lift to lift and remove the generator.  I put a strap around the back of the generator to the material lift when I pulled it out.

Then I removed the sheet metal covers top, side and back.

Changed the belt.

Reversed the procedure.

While this all occurred over several days, I estimate the actual work hours at 5 hours.  I only asked for help from my son for a few minutes when re-installing the generator, it helped to get the bolt holes lined up.

Installing a generator slide would mean sourcing a slide (I did find one at a junk yard), removing the generator, welding the slide in place, attaching the generator door to the slide, arranging the exhaust pipe to follow the slide . . . 

When needed, I'll just pull the generator out again as described above.

Dwight

 

Thanks for this write up. I’ve wondered how it comes out, and it seems like less hassle than I expected.

[Chuck B 2004 Windsor]

I took my 1998 Dip to an Onan dealer.  They lifted it out with a fork lift.  Chuck B 

[Dwight Lindsey]

A couple of years ago, when I was just concerned about possible belt failure and before it actually happened, I called Cummins in Ventura California and asked them about repair.  They quoted 2 hours labor for 2 guys to take the generator out and the same to put it back in.  Then any labor and parts for the repair and testing.

It sounded to me like 12 or more hours of labor plus parts.  I don't recall their labor rate, but I suspect it is North of $100 per hour.

I do recall thinking that it would probably be a repair costing $2000 or more.

And . . . they said it would be about 30 days before they could even look at it.

I thought at the time that a forklift would be necessary and when the belt finally failed, I inquired about renting a forklift.  $400 rental and $400 delivery and pickup . . .

While I wasn't confident about the manual material lift working, it worked perfectly and I did the job myself with a rented manual material lift that cost me $80 for the week.

Dwight

Edited August 29, 2023 by Dwight Lindsey