Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Kent Speers on July 11, 2011, 08:23:51 pm

Title: PowerTech 10K Vibrates the Whole Coach
Post by: Kent Speers on July 11, 2011, 08:23:51 pm
I have been very disappointed with the PowerTech generator and Kubota diesel engine on my U300 since I got it last fall due to a lot of interior noise and vibration. I had MOT check over the generator, genie exhaust and radiator to see what was touching the MH chassis. I couldn't find anything and neither could they. The isolaters seem to be perfectly good. They look like they were replaced sometime in the recent past.

Yesterday I was changing the fuel filter and noticed one of the six mounting bolts that hold the slide frame to the chassis brackets were very loose. I was only able to reach two of the six bolts but tightening them down has dramatically reduced the vibration. These bolts are hard to see and hard to reach but I think when I get back to Blanchard I can reach the other four with my long wobble extension and a deep well 9/16 socket.

I'm guessing there may be many other vintage Foretravels with the same situation. It's worth checking. The interior noise reduction with just two bolts tightened is impressive.
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: jeff on July 11, 2011, 08:31:42 pm
Kent,

I am shocked. You don't have two of those tools with you? That has to be a first.
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Kent Speers on July 11, 2011, 08:40:08 pm
I'm travelln lite this week. Its too darn hot to carry everything.
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Bill Chaplin on July 11, 2011, 08:45:18 pm
Check with Peg before using the "woble Extention" on you mounts
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Dave Head on July 11, 2011, 09:42:07 pm
While I can't say the 10KW unit in my 93 was real quiet I was very satisfied with it. The 95 is a shade quieter, I expect mainly due to front end mounting rather than under the J-lounge.
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Bill Willett on July 12, 2011, 08:25:02 am
Power Tech has Firestone air bags for your genny.
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Pierce & Gaylie Stewart on July 12, 2011, 10:46:57 am
Power Tech has Firestone air bags for your genny.

Kent,

Good work on finding the loose bolts! Will look at mine as I also have not been really happy with the noise and vibration. Bill may be on to something in the quoted post. Mounts that look good may not be doing the best job because of design, etc. Isolating noise and vibration is more than throwing some mounts on. My Onan generator in the old, old Southwind still runs great and you can't really tell it is running when inside the old girl. I have a new Onan Emerald sitting on my garage floor gathering dust. Sometimes feel like throwing it in the compartment. I can never feel any vibration of any kind at any RPM from the Detroit, just the great exhaust note with the window open. The PowerTech should be the same.

We take ours a little off road in getting to some campsites and while I have not scraped the bottom, I have hit the 90 where the exhaust comes out underneath. A future project will to investigate sending the exhaust forward and then out without the pipe being exposed. I think I will change muffler design and increase the pipe size as I don't like the hiss that goes with the exhaust note.

Bottom line is the 10Kw genny is meant to be seen, not heard and can be trained to be that way.

Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Pierce & Gaylie Stewart on July 12, 2011, 10:50:55 am
Power Tech has Firestone air bags for your genny.

Hey Bill,

How about the part number on those Firestones?
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Bill Willett on July 12, 2011, 03:09:46 pm
Firestone Industrial Products W01-358-7001 Air bag, they are not cheap from Power Tech,
 $130.00.
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Kent Speers on July 12, 2011, 03:32:49 pm
My PowerTech seems to be very quiet outside the coach. The vibration in the coach is my big gripe. If tightening the additional bolts doesn't do the job, I might try the Firestone isolaters if they will work on my older mounting system.

Pierce, let me know if you figure anything out. I will do the same.
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Pierce & Gaylie Stewart on July 12, 2011, 05:34:04 pm
Kent,

Figured that was not too bad to do a generator but looked them up and found that is the price for ONE! Thats almost $600 including shipping for 4. Found a used one on ebay to look at. $89 plus shipping. Here it is: NEW FIRESTONE W01-358-7001 CONVOLUTED BUS AIR SPRING on eBay! (http://compare.ebay.com/like/140545816354?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&_lwgsi=y)

Will give your tightening technique and other options a try first.
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Dave M (RIP) on July 12, 2011, 05:47:32 pm
Think the word "Proper" is abused by some when it comes to the rubber mounting cushions on generators. Can assure you I have seen many variations of "simple" mounting, wrong and creative home grown ideas with the overall vibrations were expected.  Along with ducting and exhaust mounting all contribute to how smooth one will run.
Have seen gensets that are a known rough runner (Onan JB Series) installed where they did not vibrate the vehicle.
It should not be a major issue to isolate a 2 cylinder Onan or a 4 cylinder Kubota where you might hear it, but any vibrations would be very minimal at most. 
Do not think Foretravel could sell a coach with a noisy and vibrating generator. ?
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: pocketchange on September 08, 2013, 08:42:34 pm
Goodyear Air-Spring # 1B5-500 is the crossover part number for the
Firestone W01-358-7001 Air-Spring. 

Now for the best part.. if you have an interest in switching over to these,
the Goodyear Air-Spring is $72.00.

I located the Goodyear Air-Spring via Google.

I'd be interested to hear from someone that has made the change and get a report on the upgrade and if it's worth the extra cost of the OEM cushions.







Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Dave M (RIP) on September 08, 2013, 09:32:42 pm
Is that $72.00 for one bag or the kit ?  Is there a kit ?  How many bags are needed ?
I find my 10kw 4 cylinder Kubota very smooth and quiet inside, yes you can hear it IF the TV & a/c is off, other wise it is not there when running. Zero, Nadda, Zip etc ;D
No idea Kent how yours is mounted, Is it on the side under the coach or in front center ?
Clearly under the couch would be more noticeable. ?

I would not be interested in the air bags, even if they were FREE, just more headache, leaks and problems with suspension & rubbing hoses & wire.  My point, why fix what does not need fixed ?  If you have an issue, FIX it with the normal parts as designed.
My Opinion of course
Dave M
Title: Re: PowerTech 10K Vibrates the Whole Coach
Post by: Pierce & Gaylie Stewart on September 08, 2013, 09:49:27 pm
Dave,

Ours are in the first compartment back on the driver's side and right under the sofa (straight sofa on ours).

Everyone with GV and a 10Kw (or 7.5) should pull the generator tray out and check the flexible exhaust pipe for vibrating against the inside wall. Ours had burned through the insulation and was rubbing against the metal.

Damaged generator mounts can be checked at the same time as you can't see the damage from the top, only by looking up from the bottom. Ours are shot.

Pierce