i understand why the dually trucks, such as an F550, are not as good traction-wise as a single rear wheel truck. would it be possible to get all six wheels to spin and brake using some sort of an after market idea? am i nuts?

 

I'm not really following you here. A 4x4 with lockers would turn all tires. Or are you thinking something completely different?

 

my understanding is that the purpose of the extra 2 rear tires are for stability only. wouldn't it be nice if ALL 6 tires accelerated and braked? in other words...a 6 wheel drive and 6 wheel braking.
thanks for your reply

 

like said before if it were 4WD with lockers thats what u would have....

 

any disadvantages to using lockers?

 

Are you talking about a dually or are you talking about a 6x6 with two seperate rear axles? On a dually there's 2 tires per side but they're all on the same axle. They all turn and they all brake. There are custom made 6x6 trucks with 2 rear axles, typically both axles are powered so that all wheels are working.

Disadvantage to lockers is they can cause some unexpected driving quirks, particularly on wet or icy roads as the rear end will go from an open diff to fully locked on acceleration. This isn't a problem in a straight line but can cause loss of control going around a corner if you're not used to driving it. The other option is a selectable locker like ARB or Electrac where you have an open diff until you flip a switch and then the rear end acts like a spool.

 

i'm talking about a dually, 2 tires per side, on 1 axle. in other words...all 6 tires accelerate and brake. an aquaintance recently told me that only the inner tires accelerate and brake and that the outer tires do nothing but turn and act as more stabilty for heavier/wider loads. if for some crazy reason i need serious traction in the middle of ni-where it would be nice not to get stuck. will probably install a winch as backup.

seriously considering the new f550 reg cab dually diesel 84'' CA for pulling gooseneck trailers and/or loading heavy stones onto a custom dump box. i like the idea of having a little more truck than i need because i've always disliked maxing anything out. my current 2003 toyota tundra longbox really sucks for payload.

 

Your aquaintance was high on crack. On a dually the outer wheels and the inner wheels are sitting on the same lug nuts. How can the inside tires accelerate and brake without the outside tires doing anything?? Get a 4x4 dually. You'll be amazed where it will go. If you still need more traction add lockers. One advantage to a dually on soft terrain is the spread out weight in the rear tends to float atop soft ground better, rather than sinking into it like a single tire.

 

makes more sense to me now. never owned a dually and not nearly as mechanically inclined as most of the people on this site. owned an 85' f250 for awhile but the 460 stole all my gas $.

i'm still not clear how lockers give more traction. actually never heard of it til yesterday. your knowledge appreciated.
is it an after market product that an outfitter installs? a mechanic? myself?

 

I'm a lazy typer so I won't get into too much detail but let's see if I can explain it.

The carrier (differential) in your rear axle (and front axle on a 4x4) allows the tires to turn at different speeds because as you go around a corner the outer tires must turn faster than the inner tires, follow me? But the way an open carrier works it'll put the power to whichever tire has the least resistance. This is why if you get stuck and step on the gas a lot of times only 1 tire will be spinning, also if you jack up the rear of a truck and spin 1 tire forward the other spins backward, this is all due to the open carrier. What a locker does is it can allow you to turn corners and have the tires spinning at different speeds but when you accelerate it will lock the carrier so that both tires are getting equal power. This allows both tires to spin in the mud. The downside as mentioned is if you try to accelerate around a corner it wants to lock up but you need the outer tire to spin faster than the inner. So the result is that one tire squeals as you take the corner or in slick conditions it can cause 1 or both tires to break loose completely. You can install an air locker that acts like an open differential normally but can be "switched" on by a control in the cab to fully lock the rear axle for traction when you need it most.

Another option here is "limited slip" carriers or what you may know as posi-traction rear ends. These use clutches like an automatic transmission to put power to both tires but they don't lock up like a full locker so they're much easier to drive with. They will still leave you with only one tire spinning sometimes.