Rollback weight questions

No, the smaller chassis can't safely or legally pull two cars at a time unless they are very light cars. The 450/4500 has a 16,000 or 17,500 GVWR and the 550/5500 series is 19,500. Both will have a tare weight around 13-14k depending on gas or diesel and steel or aluminum deck.

The 26k GVWR units are better, but not by much eventhough they are used daily as 2 car carriers. They typically have a tare weight of 17-17,500 which only leaves around 8k to be split between the hauled vehicle and the towed vehicle.

As for how the weights are looked at, the weight of the hauled vehicle obviously is 100% on the truck's axles. The towed vehicle has about 40% of its weight transferring to the tow truck and the rest riding on its own axle that is still on the ground. This will add the weight of the towed vehicle to the drive axle of the faltbed plus move about 10% of the weight from the flatbed's steer axle backwards to the drive axle due to the see saw effect of lifting the weight on the wheel lift behind the rear axle.

It is real easy to overload the drive axle on a two car flatbed carrier when towing anything bigger than a small SUV.

As for your last question, to remain non-cdl the weight on the flatbed's two axles (steer and drive) must not ever exceed 26,000 pounds and the vehicle in tow must never exceed 10,000 pounds or have a GVWR of more than 10,000 pounds. DOT will check the truck axle weights and the door jamb of the towed vehicle.

Also note, the typical 2 car flatbed may have a deck rating higher than what the chassis can support because those same decks get mounted on larger chassis. They typically have a 6 ton (12k) rating which is a water load rating (meaning 1 inch of water evenly spread out) but when you look at the tare weight of the truck it can't usually support more than 8k on it.

Also, the typical wheel lift on a 2 car rollback has a 3,500 or 4,000 pound lift rating and a 10,000 tow rating with some having a lower tow rating.

Be sure to study the rating plates and get a scale ticket before deciding if the truck can haul what you intend to haul.

 

Good and thorough explanation there, Brian.
Had 7 trucks since 1983, several were 17,500.
I now run Freightliner M2 106 chassis that are 26000 lb. G.V.W.
I have one with a 3126 Cat and one w/Mercedes.
The Cat is a 6 speed manual, Mercedes one is Allison.
Both have wheel lifts @ 4000 lb.
I towed a MB Sprinter the other day on a Chevy Top kick wheel lift,
because it would be too high if I loaded it on the deck.

I just acquired an 8' X 20' plate of 3/8" steel to make a heavy haul deck.
(Next summer's truck build project.)
I Noted the sheet's 1200 lb weight, but it's worth it.
I replace the ribs of sheet steel with 2" X 6" rectangular tubing.

I use a Chevy Top kick 26,000 G.V.W. w/3126 Cat for wheel lift jobs
cause it works sweet compared to the Freightliners.

I don't generally find the juice of wheel lifts worth the squeeze.
If I "hook and book," wheel lift just slows me down,
but for 50 miles or more - it's worth the time and hassle.