RV Trip Planning Discussions

Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > Newmar Owner's Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 06-10-2018, 02:14 PM   #1
Community Moderator
 
Spk64's Avatar


 
Newmar Owners Club
Join Date: Apr 2014
Location: Southern Indiana
Posts: 9,011
Onan 7500 belt replacement

With our generator just kicking over past 1000 hours I had debated the need to change the belt. Some say to let it go till it fails others did a visual and said it looked fine. Not being one who wants to deal with something after it fails I chose to replace the belt.
Since I had been doing other work in the front and had it up in the air decided to tackle the belt change.
I searched around and could not find many details on cover removal. The service manual has a process that only works if genset is out. What I did find out is the top needs removed.
Here is what I found out and what worked with our genset on a slide.
1. Pull generator slide out to access rear.
2. Remove all the bolts holding top cover and may need to loosen some of the bolts on the front side. Then remove the top cover it has to slide back but also right front needs lifted over coolant tank.
3. Fuel lines need removed, be prepared to catch some fuel when lines removed. I placed 5 gallon bucket below. Couple ounces will drain out.
4. Remove battery cables.
5. Remove all bolts holding rear cover.
6. This is the part that was not really mentioned. But loosening or removing all the bolts on the side panels will make it easier to get the back panel out.
7. Remove back panel by lifting up, helps to lift the left side looking from back up also then slide back panel left then it will come back some to drop it out the bottom.
8. Remove 4 bolts holding pulley to water pump.
9. Remove old belt place new belt over bottom pulley then with belt on removed pulley place it back on pump. It may be a little snug as there is not a tensioner on the belt. Replace belt.
10. Replace rear cover and replace all the bolts, lines cables. This part actually goes much quicker than the removal process.
Total time was around 2 hours moving slowly.
Not a job you want to do when out on the road.
Your done for another 5 years or 1000 hours!

Genset slide out and ready to begin disassembly.
Click image for larger version

Name:	IMG_4120.jpg
Views:	133
Size:	273.8 KB
ID:	206581
Back side showing fuel and battery cables in the way.
Click image for larger version

Name:	IMG_4119.jpg
Views:	119
Size:	197.9 KB
ID:	206582
Top cover removed
Click image for larger version

Name:	IMG_4121.jpg
Views:	193
Size:	358.0 KB
ID:	206583
And the belt ready for replacement. Also note fuel lines have rags covering to prevent debris from entering fuel system.
Click image for larger version

Name:	IMG_4125.jpg
Views:	146
Size:	211.1 KB
ID:	206584
Lines and cables up out of way. I did use a hose clamp to prevent excess fuel leaking on line from tank.
Click image for larger version

Name:	IMG_4126.jpg
Views:	97
Size:	229.7 KB
ID:	206585
Old and new belt
Click image for larger version

Name:	IMG_4127.jpg
Views:	137
Size:	265.3 KB
ID:	206586
Old belt with some cracks barely visible. These cracks are very difficult to see on the motor. If the belt is removed and bent backwards you see how bad they really are.
Click image for larger version

Name:	IMG_4128.jpg
Views:	108
Size:	234.2 KB
ID:	206587

Hope this helps anyone else tackling this job.
__________________

__________________
Steve
2002 Newmar Mountain Aire 4095
Spk64 is online now   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 06-10-2018, 02:33 PM   #2
Senior Member
 
tizzyfit's Avatar
 
Join Date: Sep 2002
Location: seattle,wa USA
Posts: 1,013
Thanks, Steve for the write-up. You're lucky your generator pulls out. I'm going through the same process with my Generac 75D only mine needs to be pulled out to accomplish the belt/tensioner replacement. What other components are you replacing now that the cover panels are removed? I've decided to replace the radiator hoses, thermostat, cooling fan belt and tensioner but I've got almost 5,000 hours on the meter and I sure don't want to have to pull this beast out again because a $25 part that could have been replaced was left in.
__________________

__________________
Gary, Maxwell and the Beanie Weenie.
2002 Newmar Kountry Star. Cummins ISB 24 valve
2017 Mazda Miata MX-5 toad on a double axle car hauling trailer
tizzyfit is offline   Reply With Quote
Old 06-10-2018, 03:00 PM   #3
Community Moderator
 
Spk64's Avatar


 
Newmar Owners Club
Join Date: Apr 2014
Location: Southern Indiana
Posts: 9,011
Quote:
Originally Posted by tizzyfit View Post
Thanks, Steve for the write-up. You're lucky your generator pulls out. I'm going through the same process with my Generac 75D only mine needs to be pulled out to accomplish the belt/tensioner replacement. What other components are you replacing now that the cover panels are removed? I've decided to replace the radiator hoses, thermostat, cooling fan belt and tensioner but I've got almost 5,000 hours on the meter and I sure don't want to have to pull this beast out again because a $25 part that could have been replaced was left in.


There were 3 items on the 1000 hour. Belt, hoses and tstat and clean crankcase filter.
I checked the hoses and they looked like new. I may change them out soon but did not see anything alarming.
I had read about people changing the temp sensor but also read where they have replaced them multiple times. So far we have not had any signs of the sensor acting up so leaving it alone.
Being on a slide definitely makes it an easier job. I cannot imagine having to remove a genset for service on a regular basis.
__________________
Steve
2002 Newmar Mountain Aire 4095
Spk64 is online now   Reply With Quote
Old 06-10-2018, 03:07 PM   #4
Senior Member
 
tizzyfit's Avatar
 
Join Date: Sep 2002
Location: seattle,wa USA
Posts: 1,013
Fortunately, the diesel mechanic who is actually doing the work has a forklift and has pulled in place generators out before. He looked it over very closely and felt comfortable it would take around an hour to get it out. We'll see............
__________________
Gary, Maxwell and the Beanie Weenie.
2002 Newmar Kountry Star. Cummins ISB 24 valve
2017 Mazda Miata MX-5 toad on a double axle car hauling trailer
tizzyfit is offline   Reply With Quote
Old 06-10-2018, 04:03 PM   #5
Community Moderator
 
Spk64's Avatar


 
Newmar Owners Club
Join Date: Apr 2014
Location: Southern Indiana
Posts: 9,011
Something I forgot to add in the original post.
If you remove all the lower bolts on the cover. Take note they are a different length. The are slightly longer than all the other cover bolts.
__________________
Steve
2002 Newmar Mountain Aire 4095
Spk64 is online now   Reply With Quote
Old 02-12-2019, 11:04 PM   #6
Junior Member
 
Skier66's Avatar
 
Join Date: Mar 2011
Posts: 10
Replacing the water pump belt in Onan 7.5 KW

Steve: That was an excellent writeup! I have a 99 American Eagle with a 7.5 KW Onan, I got the Cummins service manual but it does not state there that you need to remove or disconnect the fuel lines. Was that necessary in your setup? Thanks, Carlos Medica
__________________
Skier66
Skier66 is offline   Reply With Quote
Old 02-13-2019, 07:50 AM   #7
Community Moderator
 
Spk64's Avatar


 
Newmar Owners Club
Join Date: Apr 2014
Location: Southern Indiana
Posts: 9,011
I had to remove the fuel lines and the battery cables from the back of the unit in order to get the cover off.
The pictures show the back of the unit and you can see the fuel lines and battery cables are blocking the rear cover for removal. The covers do not easily slide out, takes some maneuvering of the panel and the side covers to get it out.
__________________
Steve
2002 Newmar Mountain Aire 4095
Spk64 is online now   Reply With Quote
Old 08-29-2019, 01:52 PM   #8
Senior Member
 
Join Date: Jul 2014
Posts: 453
500 Hour Onan 7500 Quiet Diesel Service - Belt, Coolant, Thermo, Temp Sensor + Oil

I decided to let Power Field Services (PFS) in Dickenson, TX do a 500 hour service on my generator while I took a cruise out of Galveston (20 miles away). They are also an Onan certified repair facility and RV friendly!

All I had to do was make an appointment; drop off my coach on Sunday outside the gate, but on their property; put my keys in the night drop box; and pick the RV up 7 days later... outside the gate when I returned from my cruise on a Sunday. (Very convenient!)

They charged me 4 hours time to do the above services and sent me pictures of my cracked generator belt. (See below.)

Note: The Onan service manual says to change the belt at 1000 hours, but we elected to do that at 500 because there was one bad crack; and the belt was 15 years old. There were smaller cracks that did not concern us. The point is this: If you have a 15+ year old belt, you might want to inspect it or just change it since getting to the belt is half the work.

Thank you OP for telling us how to change the belt. That said, I presume the job is a lot easier if you have a slideout generator tray.

I also elected to let PFS change the coolant and thermostat, even though I could have done that myself. Again, after 15 years I felt it was time to change the coolant... but the PFS mechanic said the the loss of conditioners in the coolant (that prevent rust) are probably the bigger reason to change the coolant. He also recommended to replace the Temperature Sensor since he said this part can get rusty. He added: "If you engine starts and then stops one minute later, this symptom might be linked to a rusty Temperature Sensor.

Normally, I would do my own fluids change too, but since I saved $90 in parking fees by leaving my RV at PFS I decided to let them do the whole schmiel. ...And then I took to tow car to the port for easy and quick parking.

So if you are on the road and decide to take a cruise out of Galveston, why not book some generator service with PFS and save $90 in parking fees and the headache of finding parking for your RV at the port of Galveston.

PFS has a very RV friendly company culture. They have a very large and secure yard; and they will be glad to help coordinate a service while you are on your cruise.

Contact: Lindsey or Jay at 281-241-4767.

https://www.powerfieldservices.com/about-us/

PS I like changed from Shell Rotella to Chevron 400SDE (15W-40W) oil and I have had very good success adding 5-10oz of Rislone. Why Rislone? Well, I found this stuff quiets down the Onan lifters and that's good enough proof for me to think this stuff works!

Alternatively, can just do a 3 quart oil change like normal... and then if you need to add 3-5 oz of Rislone ~100 hours later... I have done that too. This way Rislone acts like a conditioner for the last 50 hours of generator use. And then change the generator oil at 150 hours. Try Rislone and see if you like it! ...I'm a big fan of this stuff!!! (But just buy the standard stuff approved for diesel engines. Don't use the "high mileage" Rislone unless your generator is smoking a lot.)

PSS
RCCL Liberty Of The Seas is a fantastic ship!
Attached Thumbnails
Click image for larger version

Name:	7500 Onan Belt Crack.jpg
Views:	24
Size:	149.3 KB
ID:	258393   Click image for larger version

Name:	7500 Onan Belt Crack2.jpg
Views:	32
Size:	260.0 KB
ID:	258394  

Click image for larger version

Name:	Rislone.jpg
Views:	22
Size:	167.6 KB
ID:	258398   Click image for larger version

Name:	Chevron Delo 400SDE 15W-40 Oil.jpg
Views:	25
Size:	119.1 KB
ID:	258399  

__________________
2004 Itasca "Horizon" 40AD, ISC-350HP Cummins with 100,000 miles... and the best of 3 Diesels I have owned thus far!
imnprsd is offline   Reply With Quote
Old 08-29-2019, 06:34 PM   #9
Senior Member
 
Join Date: Jun 2016
Posts: 394
I have the same gen in an 05 purchased from the original owner. At 600 I’m on pins and needles also over the belt. It’s not on a slide out also . Do you mind me asking what the charge was ?
Journey cat is offline   Reply With Quote
Old 08-30-2019, 01:42 AM   #10
Senior Member
 
Join Date: Jul 2014
Posts: 453
The PFS mechanic was kind enough to clarify a few points on my Onan 7500 service:

1) 7.5 generator belts typically last 8-10 years or 1000 hours. However, dusty and dry weather will shorten the lifespan. In this case, it looks like age caused your bet to crack to the point it should be replaced. (I have 570 hours on my generator.)

2) Your temperature sender did have a small bit of corrosion growing. This corrosion will cause a slight deformation in the electrode. This deformation will grow and over 1-2 years time could create a hole that will eventually short the sender out.

Looking at the picture, you might have been able to run your generator for 1-2 years before you had a "hard failure", but more likely you would experience these symptoms very soon:

* A faulty temp sender can make the generator take longer to start. (Yes, that was my problem but only randomly.)

* Further, it will cause the preheat to stay on for up to 30 seconds before starting. So don't be surprised when you have to hold the generator start button down longer when your Temperature Sender is corroded.

* This can also cause your generator to shutdown randomly. (Which did happen once before I serviced it.) Why... I am not certain. I think it's possible the cavity can trap air... and the hot air produces faulty sensor readings.

* The corrosion will also grow more rapidly once it begins. This is caused by the two dissimilar metals and DC current coming in contact with the coolant.

In any event, we owners change the temperature sensor when the generator is 15+ year old generator, no matter how many hours are on the meter.

Owner's comment: At some point, you will have to pay for your generator to be serviced. PFS did all the things I mentioned and billed me 4 hours at $125/hour plus parts. I will pick up my coach next week and let you know what the total bill becomes.

Also, my coach was a El Paso coach for the first 5 years and then called Northeast Texas home. So this is close to as-dry as you can get. I frankly was surprised to see bad cracks at 570 hours. So the mechanic maybe correct about dry weather and dust accelerating my belt wear. And I'm sure there are tons of owners with 2000+ hours on their generator and have never changed their belt.

So I would not change the belt unless there are obvious cracks. The problem is that you almost have to take the belt off to pinch in in such a way that you see the cracks. So examine your belt very closely when it's still on the pulley and then rotate the belt several times... looking for deep cracks.

Again... the effort involved in pulling the cover... you might as wall replace the belt. I think it's less than $20 for the part and it will last you 15+ more years. So while there is no hurry, there is also no sense waiting 1-2 years to change the belt if you see yourself owning the RV beyond 2 years. I.e., you will have to spent the money anyway.

And I choose to spend it now only because it was convenient. Remember I was going on a cruise and I had to park the coach somewhere so why not save the parking fees at the cruise port and schedule some generator service?

Now that 1 deep crack was found, I am glad I am spending the money now, because I would not want to know what could happen if you break a belt, and your generator overheats. I think there is a safety shut down for over temperature conditions, but I don't know.

Can anyone tell us what happens when you generator belt brakes and you don't know it happened? What sort of repairs might be involved then?
Attached Thumbnails
Click image for larger version

Name:	Onan Temperature Sender.jpg
Views:	24
Size:	134.3 KB
ID:	258476  
__________________
2004 Itasca "Horizon" 40AD, ISC-350HP Cummins with 100,000 miles... and the best of 3 Diesels I have owned thus far!
imnprsd is offline   Reply With Quote
Old 08-30-2019, 02:14 PM   #11
Senior Member
 
Join Date: Jun 2016
Posts: 394
I may be wrong. Although I believe if it gets hot it will shut down .
Journey cat is offline   Reply With Quote
Old 11-23-2019, 01:35 PM   #12
Senior Member
 
Join Date: Jun 2016
Posts: 394
I removed my 7500 yesterday with 1000 hours . Allso to find several cracks in the 15 yo belt .
Would you happen to know the paet number for that belt ? As mine states Onan 0511 - 0187 . Is there a new number for that belt ? As the only one I can find by that number is on E Bay with a date of 05 . I would not want to purchase a new old belt .Here is a link to that . https://www.ebay.com/itm/New-Onan-05...4383.l4275.c10
Journey cat is offline   Reply With Quote
Old 11-23-2019, 02:59 PM   #13
Senior Member
 
Join Date: Jul 2014
Posts: 453
Onan 7500 Quiet Diesel (HDKAJ) PART NUMBERS

Belt: 0511-0235
Temp Sender: 193-0318
Thermostat: A046Z961 Gasket: 185-2238
Fuel Filter: 149-2513
Oil Filter: 122-0833 (Capacity: 3 qts inc. filter)

Don't forget to purge your exhaust. ...I forgot the size of that bolt. Maybe someone can tell us? ...And you will need an ~10"+ long extension to get to it.
__________________
2004 Itasca "Horizon" 40AD, ISC-350HP Cummins with 100,000 miles... and the best of 3 Diesels I have owned thus far!
imnprsd is offline   Reply With Quote
Old 11-23-2019, 05:04 PM   #14
Senior Member
 
Join Date: Jun 2016
Posts: 394
Thus the number for the belt has changed ? Thank You .
Yes I have all 3 filters . I did the purge the exhaust 6 month back . And will do so once again . I will check the temp sensor . Although there are no signs of crust around the treads
Also was going to check valve clearance . Hoses LOOK good from the outside but one never knows . Im not happy to see the way the fill hose from radiator cap bends .
That may be a weak link in the chain !
.
__________________

Journey cat is offline   Reply With Quote
Reply

Tags
ace, onan, replace, replacement



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Onan 7.5 Water Pump Belt Replacement jbenalpine Alpine Coach Owner's Forum 5 06-05-2017 01:05 PM
Quiet Diesel 7500 belt reosw RV Systems & Appliances 6 12-22-2015 11:53 AM
Onan Drive Belt Replacement Red Dawg RV Systems & Appliances 14 10-11-2015 10:39 AM
Onan 7500 problem Pusherpilot Monaco Owner's Forum 2 10-20-2009 10:13 PM
Onan 7500 GenSet - Maintainance?? H. Miller MH-General Discussions & Problems 3 04-17-2009 10:16 PM

» Featured Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:22 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×