3/4 ton suspension upgrade

[Fargo53]

I have a 53 3/4 ton Fargo dually and I'm looking to upgrade the suspension as I want the option to pull my 5th wheel RV.

Wondering if its easier to put the cab on a newer chassis or put a front end, motor, and rear end in it. Thanks.

[Radarsonwheels]

I see nobody answered this and since I am clueless about towing my inclination is to leave it alone but if nobody wants to step up with hard earned knowledge here’s my worthless opinion:

 

Swapping the frame to modern running gear is great but not easy. It is a ton of work. You will gain modern brakes which is probably the biggest improvement in my opinion. 

 

Our trucks came with solid front and rear axles on leafs which aren’t really too different from many modern heavy duty set ups? If everything is in good working order and not beat up you might come out ahead to just refresh everything and weld up a tow bar to the frame.

 

Now is it a good idea and can you trust other people to act in a way that will keep you out of trouble no matter how carefully you drive? And will truck enforcement and highway patrol think your antique tow rig is as cool as I would?

 

Sorry for more questions than answers! Good luck and hopefully folks with better info will chime in to help.

[59bisquik]

I guess it depends on how big the trailer is. A modern truck would have better suspension, drivetrain and brakes to help with the heavier load. I also think about the legal aspect. If you were to get into an accident and for example the truck is rated for 6k lbs and the trailer is 10k, I believe you would be liable even though you were not at fault. But then again, that might depend on state.

 

So how much does this trailer weigh and how much is a 53 3/4 ton rated at? 

[kencombs]

IMO, your suspension, if in good condition, is more than adequate for a reasonable trailer weight.  That is assuming you will be happy with the cruise speed afforded by the rear gears.  The bigger issue will be power.  It takes a fair amount of HP to drag a big box down the highway.  If you want to lower the cruise RPM using a different differential gearset, the power issue becomes more difficult.  Adding power by changing to a modern engine may be a requirment, if you need more speed, or are in mountainous areas.

[CO54]

I'd also thought about setting up my 3/4 ton for towing my 3500# popup camper.  After some consideration and seeing what the total GVW is on the truck and not really feeling comfortable with the power I'll have in the mountains I've turned against that option for me.  Even with an engine upgrade and other items, I still wouldn't feel comfortable towing without doing some serious frame stiffening in the rear to support the additional trailer weight and inertia from a hard stop.

[wayfarer]

IMHO, a 53 ¾t would be a poor choice to drag a 5th wheel of any size.  The 53 is not a heavy as a newer ¾ and any side wind would push you all over the road...assuming that you could stay on the road....

Depending on the trailer, even some of the small 5th wheel units will have 2,000lbs or more in the bed and gross weight above 8k.........

[JBNeal]

Whenever the towing issue pops up on a vintage machine, I notice ppl overlook one thing:  speed...these trucks were designed before the advent of the interstate highway system, and from what I've seen and heard, speed limits back then, in many locations, were much lower than today, somewhere in the 40mph range.  This was done for safety reasons as bias ply tires and unboosted drum brakes were prominent.  So the vintage machines could do the work, but not in any hurry...modern powertrains have more power (to go and to whoa), and are more stable with radial tires and robust suspensions.  So whenever somebody wants modern performance with the retro look, then I recommend going with the body swap on the modern powertrain...the framework is proven, so grafting the body onto it is the real challenge, not engineering a powertrain into an antiquated framework