Remount camper
- Thread starter garybo
- Start date
dhackney
Expedition Leader
RE: placement of mounts, etc.
The highest stress point for the frame on your truck is just behind the cab (that's not just yours, it's true of all normal straight trucks & semi tractors). That means it's best to pay particular attention to the forward-most mounts and know that your frame is under the most stress at that point.
For that reason, it's best to not rigidly mount the load just behind the cab, like we did, but in any and all payload suspension designs, to let the load move / pivot there (we are rigidly mounted there due to the garage to camper interface clearance, we couldn't have the camper banging on the garage, and besides, in the three weeks I had to design ours I was dramatically under-researched, under-informed and unprepared, including knowing where the highest-stress point was on the frame).
In your case, if you use five Ozzie mounts per frame rail, you should be more than OK. You may also find that at least one of the Ozzie manufacturers can be very helpful in your challenge.
It is critical to distribute the payload weight along the longitudinal (length) of your frame.
RE: weight - springs
Custom spring packs are a very good idea.
Completely fill the truck with fluids and load it for camping.
Go to a flat scale and weight the entire truck, the front and rear axles and each corner. (For a flat scale, try a moving and storage company)
Go to a custom spring shop and have spring packs made up to match each corner's weight.
It is *much* better to use lots of thin spring leaves rather than a few thick ones. It makes the ride much more compliant and much less harsh.
We used Deaver Spring in Santa Ana, CA and were very happy with their quality and customer service http://www.deaverspring.com/
You don't need to take your truck there. Send them the weights and they can ship to you. You can have a local shop swap the spring packs. You will need an alignment after this job.
RE: weight - rating
Our FG generation's chassis is rated to a gross combined weight rating (GCWR) of 17,045 lbs / 7,731 kilos. I don't know what your generation's GCWR is, but that is an important number for you. It's the maximum combined weight of your chassis and any towed load. That basically tells you what the truck's brakes are rated to stop.
Our FG generation's front axle is rated to 5,730 lbs / 2,599 kilos.
Our FG generation's rear axle is rated to 9,480 lbs / 4,300 kilos.
Our FG generation's total GVWR is 14,050 lbs / 6,373 kilos.
Again, those are important numbers for you to discover for your generation truck.
I think you'll find that the FG components, other than possibly the frame, can easily handle your weight.
Since your truck's frame is relatively easy to access and work on, if you are concerned about the frame, then I suggest you sleeve it as illustrated in the body builder's drawings. Note that the step-up requires specific reinforcement. Be sure to do the entire frame, not just where you are attaching the mounts or load. If you only sleeve a portion of the frame you just move the stress points to the next weakest portion of the frame. ( I think you know how I learned this!
)
A truck frame shop can do this work for you.
The highest stress point for the frame on your truck is just behind the cab (that's not just yours, it's true of all normal straight trucks & semi tractors). That means it's best to pay particular attention to the forward-most mounts and know that your frame is under the most stress at that point.
For that reason, it's best to not rigidly mount the load just behind the cab, like we did, but in any and all payload suspension designs, to let the load move / pivot there (we are rigidly mounted there due to the garage to camper interface clearance, we couldn't have the camper banging on the garage, and besides, in the three weeks I had to design ours I was dramatically under-researched, under-informed and unprepared, including knowing where the highest-stress point was on the frame).
In your case, if you use five Ozzie mounts per frame rail, you should be more than OK. You may also find that at least one of the Ozzie manufacturers can be very helpful in your challenge.
It is critical to distribute the payload weight along the longitudinal (length) of your frame.
RE: weight - springs
Custom spring packs are a very good idea.
Completely fill the truck with fluids and load it for camping.
Go to a flat scale and weight the entire truck, the front and rear axles and each corner. (For a flat scale, try a moving and storage company)
Go to a custom spring shop and have spring packs made up to match each corner's weight.
It is *much* better to use lots of thin spring leaves rather than a few thick ones. It makes the ride much more compliant and much less harsh.
We used Deaver Spring in Santa Ana, CA and were very happy with their quality and customer service http://www.deaverspring.com/
You don't need to take your truck there. Send them the weights and they can ship to you. You can have a local shop swap the spring packs. You will need an alignment after this job.
RE: weight - rating
Our FG generation's chassis is rated to a gross combined weight rating (GCWR) of 17,045 lbs / 7,731 kilos. I don't know what your generation's GCWR is, but that is an important number for you. It's the maximum combined weight of your chassis and any towed load. That basically tells you what the truck's brakes are rated to stop.
Our FG generation's front axle is rated to 5,730 lbs / 2,599 kilos.
Our FG generation's rear axle is rated to 9,480 lbs / 4,300 kilos.
Our FG generation's total GVWR is 14,050 lbs / 6,373 kilos.
Again, those are important numbers for you to discover for your generation truck.
I think you'll find that the FG components, other than possibly the frame, can easily handle your weight.
Since your truck's frame is relatively easy to access and work on, if you are concerned about the frame, then I suggest you sleeve it as illustrated in the body builder's drawings. Note that the step-up requires specific reinforcement. Be sure to do the entire frame, not just where you are attaching the mounts or load. If you only sleeve a portion of the frame you just move the stress points to the next weakest portion of the frame. ( I think you know how I learned this!
) A truck frame shop can do this work for you.
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Just had the welded on spacer plates removed from the Fuso frame between the wheels and the metal smoothed out. The u bolts torqued to 75ftlbs. Got a note from Unicell saying they have switched from flat to L angle cross plates on the u bolts and confirmed the torque pressure.
Thanks Doug, for info on Lehel's rig, weights, springs, stress points, frame strengthening and more.
Thanks Owen for showing us your build up- quite impressive.
I'll think about these things after a beer!
Thanks Doug, for info on Lehel's rig, weights, springs, stress points, frame strengthening and more.
Thanks Owen for showing us your build up- quite impressive.
I'll think about these things after a beer!
dhackney
Expedition Leader
No. The problem with welding is the heat. Your frame is a tempered steel frame. The tempering process adds strength, but creates areas where you cannot introduce heat again without weakening the steel.
SkiFreak
Crazy Person
VSB6
As I mentioned in the email I sent you Gary, there is not really a "standard" mount, as subframes and chassis differ greatly.
An example of the spring mount suggested for use here in Australia, can be seen in the Vehicle Standards Bulletin No.6 , on page 14 of Section J.
Any reputable general engineering workshop should be able to manufacture custom made mounts similar to these for your setup.
As I mentioned in the email I sent you Gary, there is not really a "standard" mount, as subframes and chassis differ greatly.
An example of the spring mount suggested for use here in Australia, can be seen in the Vehicle Standards Bulletin No.6 , on page 14 of Section J.
Any reputable general engineering workshop should be able to manufacture custom made mounts similar to these for your setup.
John, look at this site, p.8
http://www.iveco.com.au/dealer.info/Service 2/DB508/A_PS_ET/A_PS_ET.pdf
this resembles the mount I asked to find. Of course it doesn't have any specific info, but others can comment on it.
http://www.iveco.com.au/dealer.info/Service 2/DB508/A_PS_ET/A_PS_ET.pdf
this resembles the mount I asked to find. Of course it doesn't have any specific info, but others can comment on it.
SkiFreak
Crazy Person
I do not believe that three or four point mounting systems, as shown in the Iveco body builder's guidelines, are really suited to the stepped chassis of a Fuso FG.
As Doug has said, the area directly behind the cab is where the most amount of flex occurs in a FG. The more you can distribute the load over the length of the chassis the better off you will be...
As Doug has said, the area directly behind the cab is where the most amount of flex occurs in a FG. The more you can distribute the load over the length of the chassis the better off you will be...
dhackney
Expedition Leader
IMO, it is always best to use the manufacturer's guidelines. They've usually put hundreds to thousands of engineering and analysis person-hours into creating those recommendations to best match the materials and design of the components.
I'm not an engineer, so I can't comment on the subtleties of the difference between an inner sleeve and an L.
From the layman's perspective, the L allows flex between the two components and the inner sleeve could cause interference/binding/wear.
Again, that's a layman's assertion and I think you are best to follow the Fuso guidelines.
The Australian Design Rule 62 states how a load can be mounted to a frame. I found this document to be only words, no pictures. Please correct me if I didn't see the picture. I posted the picture from Iveco's manual as a public domain example of the spring mount. Owen's Canter4x4 site has his rendition of the mount. If anyone can find another public domain example, please post it here.
Contacted Deaver Springs in Santa Ana CA. They will examine my springs and make the plan for new springs in one day. They say the stock Fuso springs are too close to the stops, so the new ones need to be arched higher? to prevent hitting the stops. Making new springs takes one month. Then swap the old for the new in one day. The cost is about $3500 including labor for new springs all around if needed all around.
Contacted Deaver Springs in Santa Ana CA. They will examine my springs and make the plan for new springs in one day. They say the stock Fuso springs are too close to the stops, so the new ones need to be arched higher? to prevent hitting the stops. Making new springs takes one month. Then swap the old for the new in one day. The cost is about $3500 including labor for new springs all around if needed all around.
SkiFreak
Crazy Person
As I mentioned previously, in the Australian Vehicle Standards Bulletin No.6, on page 14 of Section J, you will find information on body mounting, including different types of mounting systems.
dhackney
Expedition Leader
If Deaver extends the arch (good idea, based on our experience), that will change the required length for the shock. You'll need new shocks.
You may want to check with All Terrain Warriors (ATW) to check on the cost of their suspension upgrades for your generation FG. I don't know if they would be price competitive or not, but they've certainly got decades of experience building, fitting and sustaining those suspension components for the Fuso.