Heavy spec truck purpose?

There are places that you can go in Canada, where they give you map coordinates and the name of the nearest town (which can be a hundred miles away up a dirt trail).

If you have to take a load to Hell, you make absolutely certain that the truck you buy will bring you back. Keep that in mind, as there is nothing else that's more important than coming back from Hell.

Now, 46k rears, lockers, big frames, big front ends, big radiators come with a price: YOU ARE HEAVY.

"How heavy, Six?"

A-typical heavy 3 Canadian spec rig, complete with gear in headache rack, big tranny, bobtail...Id say 9-10000 lbs heavier than the average megafleet box truck. You are not going to get doorslammer fuel economy.

It seems that we get people that want to pull big loads that went to beancounter school, and learned trucking from ivy league beancounters, and they see heavyhaulers and think that they can adapt megafleet doorslammer beancounter economics to OSOW gigs. So they talk about the weight savings that a 9speed direct and 10 speeds have over those 2050 and 2250 transmissions, Next of course is how much weight they can save if they run a multiaxle with supersingles. Some even want to convert their twin screw into a single screw and a dummy. @nate980 has to be doing it wrong! Poor Nate...driving that big ol heavy 3 when he could be doing the same job with a lightweight truck and get a fuel bonus!

 

Because people often think they need a stouter truck than necessary to get a job done.

Having consistently overloaded rears by 35-50% of rated capacity, the 40k rears will handle it without issue if you know how to drive the truck.

 

Some states won't give overweight permits unless you have the gvwr to back it up.

 

Those trucks OP is looking at are in Canada and based on those specs he gave, likely western Canada. Most trucks with those specs are lowbedding, logging, or working in the oil patch. 1/4" frames and 40k rears won't hold up long with heavy weights and constant off highway pounding.

 

If you drive on pavement or concrete.
If you do it occasionally.
If you do it everyday, it will catch up with you.
When you take off out of a freshly plowed field grossing 140,000 lbs over eight axles, accelerate as to fast as you dare in bull-low first gear but can't shift as the truck will stop dead in its tracks. Putting over 91,000 ft-lbs of torque through the rears, climbing an approach to get onto the road, and the truck is loosing speed.
That's why we have heavy spec trucks.

 

Done it out of the mud with 50,000+ on 40k QD100 3.55s.

Heavy spec trucks have their place, but, no amount of heavy-specing a truck will make up for a driver who solely thinks the specs determine the trucks capabilities.

Give an idiot driver a 22918B, a 625 Cat, and 48k rears and they'll wreck it pulling a dry-van.

Give a skilled, knowledgeable driver a 12513 behind a 350 BC-1 and SQHD's and they'll move a D10 with it without wrecking things.

Try to remember they did this stuff years ago with 220s, 4x3s and Timken worms. Not saying we "need" to do it that way yet, but, it shows that for decades this stuff got done with engines, transmissions, and axles half the size of a DS462.

Yes, lighter spec will wear faster, but, talking about snapping axle shafts, suspension damage, etc., the overload factor necessary to do that goes far beyond the difference between 40,000lb and 46,000lb rears. Snapping an axle shaft is a catastrophic failure, generally caused by immediate loss of and regaining traction, especially if you've got the axles locked up. I don't care if they're 36,000lb or 52,000lb rears, in that situation, that axle-shaft is going to snap.

 

Well yes you do have a valid point there.
No amount of great specs will over come a gorilla behind the wheel with no finesse.

 

When I hauled Super B, we had 16k steers(long nose Petes and KWs), 46k rears, 550 hp Cat/Cummins with 1850 torque and 18 speed. Double frames too.

You ask why? Because our highways are in the same shape your county roads are in. Our bush roads are even worse. Often you get off the beaten path and you don't come out of the basement gears, pulling 140,000 lbs. Just in Ontario(no mountains), I've dropped 2-3 gears no problem on some tiny hills hauling that weight.

Someone also mentioned the weight of our heavy units...My little 3 axle tractor(heavy spec with 14.6 steer axle) with a 3 axle float and all my junk I need to chain stuff down tares in at 23,000 KGS, before I even load something on the back.

 

Lmao wow 50000 pounds a real heavy spec truck hauls 3 times that much.

 

You realize that he's talking about having 50k lbs on his drives right?? I have yet to see a true "heavy haul" truck that could handle three times that on the drives. Before you jump on me I've had 54880 on a tandem drive before even rolled thru the Casper scale with it because it's legal here in WY. That was a set of super 40's on low air leaf suspension set at 3.36 I pulled this load out of the field and it was fairly soft, never had a problem just had to be easy on the clutch.