Like so many before me, it was time to refresh the front generator section of our 2001 U295. At 22 years of age and basically zero maintenance history, I wanted to 100% refresh everything and in my case rebuild and redesign the generator pad. Our Generator has 825 hours.
The rebuild part was due to the fact that the original design of the pan the generator sits in, must have been designed by a sesame street engineer. No one with any sense would ever create a pan out of carbon steel, with sections that could not relieve themselves of any moisture. 2 sections of our mounting were like a bread pan. Then poorly painted at best, if at all, and to add to that, cover it all in a rubber sheet that helps hold any and all moisture. Being at the very front of the rig, it's a no brainer that water could get to it. It was actually still holding about ¼" of water in some section by time of my work. Sure I could have salvaged what was, but, due to the corrosion issue, one of my mounts base was totally rusted away, another close to being so. It would have taken more time and money to try and salvage a sheet of 1/8" steel that needed redesign anyway vs just to replace.
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The re-design was for two reasons, one to create a better approach for element protection as well as to come up with another approach for the mounts that actually support the Gen itself as these are becoming very hard to find and quite expensive if you do. My OE mounts were still in great shape, with exception of 1 where the metal section was heavily corroded.
I started by totally removing the bottom rusted section of the pan. The perimeter shell 1/8" was still 100% intact. I then welded a band of ¼" x 2 inch angle around it. Using 3/16" x 3" channel steel, welded in two cross beams that would act as the new mounting points for the new style mounts. After all welding and finishing, painted with heavy grade tractor implement Primer/Paint. Using a piece of 3/8" polycarbonate, created a new bottom that is screwed to the cross beams and added perimeter mounts. Placed the same holes for engine service and Gen ventilation as the original. However, this pan will never rust again.
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The new mounts I used were sourced from McMaster Carr. Rotating mass mount engineering suggests that the mount specs be based on total mass / number of mounts needed. I have read many opinions on gen weight of about 500lbs. Using bathroom scale and weighing both ends, I showed that mine was in and around 550 lbs. 550/4 = 137lbs per mount. 137lb rated were available but I didn't like the fact that those used a ¼ mounting bolt where the original were 3/8". I opted to go a bit stronger and use a 210 rated mount. These having a mounting height of 1.1" vs the Original style at ¾" height. However, as I was redesigning the entire mounting system, the added height was not an issue.
My math was slightly off on the height, and even though I could have used these mounts 100% as purchased, it would have put my engine pan almost touching my cross beams. Therefore I shimmed my mounts between mount and gen/Eng using 1/4" polycarbonate plates to get the added clearance needed. There is a 3/8" mount available that is a bit taller, but its much stiffer rubber. I prefer the approach I Used.
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I will add this comment for anyone wondering about replacing the OE with these. For the original pan design, the mounts I used could be made to work with the original metal setup by mounting below the existing mounting surface vs on top. The OE mounts are larger in diameter than these and are mounted in a very large hole with minimal actual mounting metal. But it would take a bit of effort and could only be done if the Gen assembly was fully removed from the RV as I did. But considering the ever growing issue of sourcing and pricing the OE whenever needed, I would surely have used these and did the minimum work vs trying to find and take out a loan for the OE...vs $13 each. if metal work was not part of my project. I DID NOT replace the mounts that are between the Generator pan and slide frame. But, if I ever needed to, the same style I used for the pan/Gen are available for that location.
Other than the new mounting. I replaced all hoses for the entire cooling path. New Water pump as the old had a slight weep. New TStat. New Gates 3305 Belt. Adjusted the engine valves as Kubota suggests at 800 hr intervals (.005 - .007). (Several were quite loose at around .009). New valve cover gasket. New start capacitor for the Radiator cooling fan. Refilled with the same coolant I have in the cummins (Peak final charge). New fuel lines for the pan area (entire coach lines done last year). Touched up paint on the engine. New end bearing in the Generator, Fresh gen housing paint. Re-insulted entire Gen enclosure. Cleaned and greased all bearings for the slide section. Repainted entire front of RV Gen area.
Still to finish the rear of the front hood (Gen Access Door). Its insulation was rotten and falling everywhere, as well as moisture/ light rust attacking the hinges/brackets etc., due to being covered with rubber and poorly sealed. All old mess removed/cleaned and painted all parts with POR15. Will recover with the same reflective heat/noise barrier insulation I used around the gen. Just waiting on a day where its not 100+ outside.
Once back in, all ran just like it used to. Noise, vibration, etc due to any redesign was none. I would recommend these mounts for the application should you find yourself in the same situation.. See attached picture for the details.
Mike
What you didn't include was an estimated number of hours/days involved in this project. Hats off to your meticulous attention to detail.
Awesome job of repairing a real problem with these generators! Nice write up and documentation!
Mike it looks great. Im always trying for improvements with noise and heat reduction. Ive considered wrapping the exhaust and muffler similar to inside the box, but also concerned with added corrosion to the pipe and muffler? Mine doesnt have the corrosion issues that im aware of, but I'll get on it next winter possibly. All the insulation has been ripped out so that too needs addressing. Great job. I agree with the heat. Not as easy as it once was.
Outstanding design and photos!
That's what happens on limited production vehicles when the factory does have that much experience and do many things on the cheap.
Nice work. All the forum members should get together and design a coach.
Pierce
LOL....with my busy schedule, waiting on the parts, a few weeks. But had I worked on it all day for days, and had the parts in hand. probably about 3 days. the only cost to me, was the hoses, bearing and mounts. I had all the rest in my shop.
Scott,
Inside the box it was wrapped that way from the factory, what is under there from what I can tell is the similar stainless/? flex that is on the section leading out to the Muffler. I did add the fiber wrap in the flex area as there were some spots rubbed through that orange cover and on the bottom area due to its proximity to the lexan to avoid any heat transfer there. I think our outgoing pipe and muffler is newer than OE as it just looks too good to be 22 years old, but our unit overall is very quiet.
I think in the case of this ones poor design.....had the Original and prior to us owners had been more the DIY types like you and I are, they would have noticed this was an issue early on....Maybe drill a few holes in that pan, rip out the water holding rubber/foam liner, and take the time to wipe a bit of extra paint and this never would have gotten this way. The only good thing about this was, I found it as part of my pre-inspection during purchase and was able to use it to get the price of the coach reduced by about 1K. Other than my time only spent about $200 for the repair and to put it into a much better long term condition.
The inside looks like firesleeve. Good stuff and long lived. Mine is quiet, but more is always better. In the winter having the added heat under the coach is fine, but summertime, any reduction has to help. This could also include coolant air exhaust deflection?
So were are you storing the mirrors that you place under your show coach so visitors can admire the see threw bottom exposing the inner generator in operation?
Sorry couldnt help myself, it was the very first thing that came to mind when I first read your post
Thank you for the info and the detailed presentation. Definitely adding to my bookmarks for future reference.
Your about same vintage.....if same design....take the time to inspect the top of your pan for deteriorated rubber/foam padding. If so consider removing it and cleaning that area and some fresh paint. Maybe drill a few holes in the bottom of the pan for any sort of moisture removal, particularly under the GEN section.....The OE design does not need to end up the way ours did....what I mention could be done without removing the entire assembly as we did but would be slow tedious work.
Whatever they call it appears to be in great shape other than a few holes rub points that I covered with the kevlar wrap.
Show mirrors.....you crack me up!.....I have a bunch of hushmat on hand as well, and had given though to covering the Clear bottom with it for even more noise suppression, but havent done so yet.
Amazon.com: Aeroquip FCS1210 Firesleeve Hose Flame Shield 0.75 in. I.D. 10... (https://www.amazon.com/Aeroquip-FCS1210-Firesleeve-Flame-Shield/dp/B009FO5JC6/ref=sr_1_5?crid=1UHSWH2Y6XGBE&keywords=firesleeve+3%2F4&qid=1689825896&sprefix=Firesleave%2Caps%2C164&sr=8-5&ufe=app_do%3Aamzn1.fos.f5122f16-c3e8-4386-bf32-63e904010ad0)
Comes in different sizes, this is just an example. All the aviation flex hoses have it. i used to scavenge the old firesleave for everything. Old firesleave felt the same as new. Good stuff. I would probably just use the rap since I got like three roll on the shelf. The aftermarket copies seem real good also
Great job on the refreshing job
Wow pretty pricey stuff....I have bought some similar stuff for the heater hoses on my porsche where they tie into the exhaust manifolds. But in the case of that stuff the old had cracked, Sounds like this stuff is much better.
Yes but the knock off seems to be identical?
Did you replace the end bearing on the power head? I took a look at my generator to see what this would entail. I have the quietbox version and it looks like the cabinet end panel has to be removed. Can anyone say definitively that this can or cannot be done without removing the entire generator from the coach?
I have done 2 coaches with that style quiet box and had to pull the generator out/off the slide tray. The problem was the end panel has to be removed to have enough room to remove the end bell off the generator. The problem with the cabinet end plate is that there were a couple of screws that hold it together that you can't get to without having the hole thing out.
Mike
That's what I suspected. Sounds like a project for next winter...
Yes I refreshed EVERYTHING that was aged. But mine was completely out and disassembled ( right there in my lap). I would think if you slid your gen out as far as it could go and removed that side panel it could be done, but would still be a tight job. If you remove the bar that stops the gen from coming all the way out AND blocked it from beneath to support the weight as its going to start to tilt, you'd have more room. I actually drilled a few more holes to allow to relocate that stop bar further back to allow gen to come out further for future such.
Ill add one more thing not sure if I did above. There was no records or signs when I got in there that my bearing had ever been touched. At 825 hours, which is not much...that bearing was about to go. No dust coming out, but no grease inside and when spinning in my hand could start to feel roughness. Your unit is 1 year newer than mine, unsure how many hours. But I would say anyone of a similar vintage above maybe 700 hours, I dont know that I would run my Gen until I replaced this bearing. we were a few hours of run time at best away from a major expense....IM reading 10-15K worth to replace. I used the Sealed Timken that DSD (Scott) recommended some time back. My plan if we keep the coach that long is to probably replace every 3-500 hrs or maybe 8 years whichever comes first....Even the top name bearings out there these days are not the quality they used to be, but a sealed one as the one recommended would tend to last a bit longer than the OE one that was in it.
IF that is a picture of your actual unit......I see you still have that rubber/foam water catcher inside of a sealed pan beneath that Gen. Look closely at my pictures above. You might want to remove that crap and check that pan....id be surprised if it isnt rusted all to hell.
Nicely done and a great write up too.
Great write up and great job..... I'm inspired and now forced to do this and more as the motor side isn't providing power to the ATS.... I sent you a message Mike. Hope to hear back soon. Thanks
George, it can be done, but all mounts have to be taken off and we used a 2X4 to pry up the generator to allow access to the end bearing! All sheetmetal had to be removed as well. A huge shout out to DSD (SCOTT) for his expertise and assistance on this project!
Be aware that if it fails between now and then, you might be looking at replacing more than the end bearing... Starting in 2010 and continuing forward, I don't believe there are parts available for the 10 kW generator end any longer.
Regardless with the cost of a replacement bearing that is known to fail it just makes sense to stay ahead of it and change it out every thousand hours/ five years for me.
Ours failed in 2010 with around 450 hours on it (IIRC). Had to go with a 12 kW generator end back then...
Its a very easy job once the thing is out. If you remove or relocate the metal tab on the bottom that does not allow it to come all the way out, and drill some more holes to move it further back, then you can let it come out further. Once out further could reach all that needs to be reached to do the job. I would definitely have a support under the front where its pulled out as that is a lot of weight teetering on the roller rack. BUT the entire left hand side which is a 2 piece bent panel, PLUS all the wiring going to the top section would also have to be undone. If you have to do all that might as well just take out.
Seems I recall someone talking about it on another post, and I wish I had done it but did not. If that side panel had a hole with a secondary panel, it could be slid out for the most part, remove that sub-panel do the job. If I ever do mine again, and plan to at around 500 hours or 5-7 years to do so, then I will cut a large hole in that side, make a cover, and the next time much easier.
Cutting that hole could easily be done with a grinder and thin cutoff wheel, but I would throw a towel or something over the gen in order to not have any grinder dust get into it.
James Bock.....we spoke quite a while about this but I never mentioned this thought. I'd strongly consider adding that panel as part of your refresh and you'd be set for the next time.
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Mike,
You inspired me to do a refresh on my 93 U300 generator now that I have the time to do it since retiring. I have a 10K Powertech with a 4 cylinder Kubota V1305 in the side compartment and I was able to slide it out enough to remove the radiator and service it. I also removed fan shroud/doghouse in the other compartment to gain access from behind by crawling in there!
Fortunately the slide out tray and the motor mounts were in good shape and all I had to do was tighten them up and do some painting. Upon inspection I found the back two mounts had worked loose and weren't bolted down. The ground strap was also unattached and could have lead to grounding problems.
I removed all of the old insulation off the compartment walls, ceiling and the doghouse. I scraped off the old glue and replaced it with 1" self adhesive DynaCore DynaCore 1- inch – DynamatStore (https://store.dynamat.com/products/dynacore-1-inch)
I pulled the old cracked fuel lines and replaced them with new Gates 3/8" line from NAPA. I used the old brass fittings on the the tank and new ones for the fuel pump and return line connections. Got those from Home Depot. To make it easier, I removed the rubber grommet in the back wall where the lines pass through to the fuel tank and replaced it with a new one. Also while back there I was able inspect, paint the exhaust manifold elbow for rust and re-wrap the flexible pipe with exhaust wrap from O'reillys. It was very cramped in there but it can be done!
The water pump was okay and I pulled the hoses off. All were good except the water pump return hose which I replaced with a new one. The metal water pump hose connector pipe was also good and just needed cleaning and painting. I bought a long radiator hose from O'reilly's with the right diameter and elbows to cut up for any of the other hoses if I need one.
Replaced:
Gates Truflex 1380 fan belt
Napa Gold air filter 2276, Donaldson Filter Minder RBX 00-2252
Napa fuel filter 3390
Napa Gold oil filter 1344
Prestone radiator flush
50/50 mixture of Autozone Shop Pro conventional green coolant and distilled water
Napa 15w40 heavy duty diesel motor oil
The generator starts and runs much smoother now with less vibration. Seems to be much quieter and should generate less heat. I like the new insulation from Dynamat and time will tell if it was worth the cost. It wasn't easy to do and took me a couple of weeks but glad it's done in case we have a late hurricane this year.
Jerry
Really nice project!
Please advise when you know how the insulation worked.
I am also looking to insulate the engine and gen, and, although I do not want to spend tons on insulation, want to use something that work...
Peter
Thanks Peter,
No complaints so far. I chose this product because it's new from Dynamat https://www.dynamat.com/wp-content/uploads/2023/06/DynaCore-Sell-Sheet.pdf and has both thermal insulation and sound dampening properties. It's 1 inch thick and has a strong adhesive backing. The sheets are light, very flexible and can be cut with a good pair of scissors. I bought 3 sheets of 32"x54" (36sq ft) to cover the compartment and radiator dog house.
I used Hardie board in my refrigerator compartment like Pierce suggested and that worked very well and is extremely fire resistant, but with not removing the generator this was much easier to install. It's not cheap but I will use this for my engine compartment and report the results.
Jerry
Great to hear motivated a few.....can hardly go wrong with Hushmat, Dynamat or any of the similars. Just be sure you did use a roller to aid it in adhering. I have used similar for decades in auto restoration and have had a few times where it turned loose in spots before I learned about using a simple roller for install.....the same holds true for any of the foil HVAC type tapes, if you dont use a credit card or similar to flatten them with some force, they will eventually turn loose.
As for insulation on mine, I used the foil/foam type that is commonly used around HVAC units that are in attics. Sound wise my setup seems about the same as it was before my work, which we were more than satisfied with.
Can anyone give me an approximate weight for a Powertech 12kw generator? I'm getting ready to remove mine and I'm not lucky enough to have a forklift. I would like to know how much weight I'll be dealing with.
About 620 lbs
PowerTech Generators | Quiet Diesel 12 kW Generator - PT-12KSiC (https://www.powertechgenerators.com/products/pt-12ksic)
Curious what your opinion is of the dynamat after it's been installed for a while? My generator housing is due for a revamp!
It's held up very good so far and it has helped with vibration, noise and heat. It sticks to the walls and ceiling very well, but I made sure the surface areas were scraped good and clean first for the adhesive to adhere properly. I'm going to use it in my engine compartment and any other place that could use insulation like the firewall and the bay doors. This time I will go either the DynaCore or with the new the Dynamat ProX. Dynamat® ProX heavy 120mil butyl core & thick 5mil aluminum top (https://www.dynamat.com/products/prox/)
Jerry