Perhaps this is a dumb question, but bear with me because I know little about 5th wheel towing with a pickup.
Can one of our Rams be set up, with the fith wheel hitch and the air compressor and all, to pull a regular semi trailer?
Maybe not a 40 footer, but one of the smaller ones. I'm just wondering because a friend has a new 600 Cummins 3500, and he literally bends the axles on his trailer from the sod overload. He wants to pull some serious weight, and I was thinking maybe a short semi trailer would have the load rating he needs. Perhaps this will overload the truck rating, but we'll cross that bridge after I get the answer to this.

I guess my biggest question, after setting up some air brakes would be, can the fith wheel hitch be set high enough in the bed to allo the semi trailer to clear the bed rails, and would the angle on the semi trailer be too great bny the time all this was done?

Thanks,
Chris

 

You could do it with the right hitch, the right brake setup (?) and you'd need to take your bed off.

 

You can do it. I have used my RV 5th wheel hitch to move semi trailers around in my yard. I also had a flat bed. I have seen some 1 ton pu's with the air brake controls for air brake trailers to haul smaller semi trailers. You can overload the truck real easy this way. The bigger the trailer, the more it weighs empty. Remember, once you get it rolling down the road, you have to be able to control it and stop it when the car with the blue tag on the rear view mirror pulls out in front of you. If you are going to haul more than 24,000, get a truck that is designed to handle it. If you can live with under 24,000, there are a lot of trailers out there that can handle that with ease. Make sure the brakes can handle it too.

 

A couple of points that may strike others differently... A "hot shot" flat bed that is long, like 53 foot, weighs as much as a comparable big truck flat bed and much more than an aluminum trailer for a big truck. To do it properly you would have to lose the pickup bed, the fifth wheel hight should be ok as is. A kingpin hight of over 42 inches, should handle a smaller wheeled big truck trailer.

Big problem as I see it is the control for the brakes. Adding the necessary air and valves is no problem but by law it has to be linked to the truck brakes so one pedal engages all brakes. I have been unable to find such a valve. Anyone that knows of one, I would be interested. I will be experimenting with an air over hydraulic military booster with the hydraulic blocked off and using only the air side to see if that will work. The hydraulic would be teed off of one of the truck brakes, but the output blocked. From looking at the manual on these things, I think that will work. I have that booster on a Ford with a 3208 (LN7000) with hydraulic brakes plus air system to pull air brake trailers.

The other big problem with doing such a thing. The king pin setting on a goose neck for light trucks is 0 inches, ie the coupler is dead at the front of the trailer. This requires about 52 inches to swing the trailer in a turn. That is 52 inches from the back of the cab to the pivot point of the hitch. A big truck trailer is generally a 36 inch king pin setting, the pin is 36 inches from the front of the trailer. This can be moved (with much work) but it takes about 66 inches from the back of the cab to swing a 36 inch kingpin setting. Notice that rv trailers have a negative king pin setting with the king pin out ahead of the trailer. You do not have that much room on a truck that had a 8 foot bed on it.

Weight of the trailer. I have a 40 foot aluminum trailer that is 6800 pounds, just a little lighter than the wedge car hauler that I pull. As long as you can keep the trailer weight below 10,000 pounds, you would be ok and it would tow as well as one built for the light truck. Also would have 10 times the brakes. Also make sure the fifth wheel is strong enough for that use. Also realize that you would have to have a CDL in any case as the gvwr of the trailer would be that high. Also if you should do it, make darn sure that you use a tractor protection valve and caged brakes on the trailer or DOT will eat you alive.

I have some health problems now that may keep me from doing this but my intentions are to pull a big truck trailer with mine. Probably an aluminum drop deck, read $15,000 to $20,000 used. The trailer that I pull now is 102 wide and 50 feet long.

 

Well removing the bed is not an option for my friend. He really likes his 3500 the way it looks now. I suppose a GN would be the best choice, and he'd have to deal with the weight limits involved. Maybe I'll get him a sticker for his trailer that says "DO NOT OVERLOAD". It probably won't work as long as he has that welder guy that fixes his trailer cheap.

Thanks for the info,
Chris

 

Another factor to consider is axle/wheel placement and the effect it has on pin weight. To minimize pin weight carried by "light duty" (up to and including 1-ton) pickups, those 5th wheel trailers (such as my RV - see signature) place the axles close to the midpoint of the frame so as to put about 20% of the total loaded weight of the trailer on the truck as pin weight. Class 8-type semi-trailers, however, have the axles located basically at the rear of the trailer - this placement would put 50% of the total loaded weight of the trailer on the truck as pin weight. This would result in a grossly overloaded 1-ton truck!!!

Rusty

 

When you say bending axles I am guessing that he must have a triple single or something. Why not buy a regular goose neck trailer with a Dexter 12,000# tandom dualls under it? I find it hard to believe that you would bend them. I have a 40' trailer with these axles on that I have run about 27,000# trailer weight with, no problems, and that was down a rough Canada dirt trail!!

 

Maybe he just needs a new gooseneck trailer........ They make gooseneck trailers with huge GVWs.

 

Rusty the reason that I did not mention anything about axles is that I would assume that the owner would have the concept of axle weight down pat if he is trying a conversion such as this. If he is a novice he surly does not need to get into this type of hauling. The actual commercial weight distribution is 25% for a single axle trailer. I would hope that he picks a trailer that was built for single axle use and watches the load placement. Even at that, the truck axle will be heavy and the trailer axles light for their build. In the real world the 10-22.5 tires or larger can be replaced by 19.5 or 8.25-20 equivelent to lighten the trailer weight. A drop deck would be 17.5 tires for the low load deck. He might even single out the trailer tires for this use. There are quite a number of 42 foot trailers with beaver tails made to lengthen them to 53 foot to pull cars. Freight goes on the trailer portion and cars can use the beaver tail to get the length. He will end up with a 15 foot overhang or around there. With that the trailer needs some good skid plates to avoid damage when dragging out of driveways. I have seen times when my three axles are all suspended as the tail drags.

 

Chris removing the bad or modifying it is the only way the proper dimensions can be achieved. I once saw an 80.s ford that had the bed lengthened and the bad would fold down at the chrome trim to clear the trailer. It is something like that or a flatbed does fit.

 

HID,

THIS is what I based my comments on.

Rusty

 

Oh well sometimes I don't read too well....

 

Chris, you know there is a thread in the "Get-together" section that needs your attention....

 

How many pallets of sod does your buddy haul? If he hauls more than about 4 why not let the sod company deliver them for free? They have always delivered them to my job site for me and it never cost my anything. Just trying to help.

Jason

 

He tells my his tandem axle trailer with 8K GVW has seen as much as 12K on it. Maybe he hasn't made the wisest choices on loading the trailer. I am now trying to show him the light. I was asking about this semi trailer thing on my own, before I made any suggestion of it to him. I was almost sure it wasn't feasible, but now I can explain why, if it ever comes up. I'm just gonna try and find him a GN, as that should carry enough weight for anything he does.

He hauls his own sod because he can get it to the job site when he wants it. It seems he's had problems with the suppliers being too backed up and then he's got his people standing around waiting for the delivery. I think he does get it delivered for the big jobs, but the smaller ones are the majority of what he deals with.

Again, thanks to everyone for the explanations.

Chris