I was curious as to why all Pickups still insist on having a body on frame construction with the exception of the Honda (I think). Many years ago I had a Ford Econoline pickup which had no frame rails per se and the bed was continuous with the cab, essentially a unibody. You could feel the difference in handling and creaking noises when going diagonally over a ridge in your path. I once broke a rear window going over rough terrain in a '72 Chevy pickup it twisted so much. Unibody construction was popularized in the late '50’s with the Mini with Detroit finally catching up by the late '70’s or so. What could possibly be the reason for sticking with a construction technique that goes back to the dawn of the automobile?
sometimes it’s just that old habits die hard.
Also it could be if one company moves to unibody trucks they are afraid the others will run ads against them.
Ford tried it for 1961 - 63. Granted FEA analysis hadn’t been invented yet.
“Shortly after the trucks went on sale, buyers discovered that putting heavy cargo in the unibody trucks could cause the one-piece body to flex with interesting consequences. Stories percolating through the Internet tell of unibody owners who would load their trucks, only to discover that the sills had distorted enough to jam the doors shut. Yet others tell tales of having a fully laden truck twist badly enough to pop a door open when crossing railroad tracks. Age and corrosion only exacerbated issues as the load-bearing bodies began to perforate and rust.”
In the US pickups really are used for hauling and the presence of visible structure is a practical design technique and selling point. Also this structure facilitates various wheelbases, 2WD/4WD, different bed types and lengths, and commercial utility beds.
The Honda Ridgeline is sort of a boutique vehicle which is quite hard to load because of it’s “fastback” roofline, high rear bumper, and lack of adaptability to commercial use.
Unibody design is inherently only suited for lighter vehicles. And especially not for vehicles whose weight is going to vary by a large amount (i.e. adding heavy cargo). Trucks are both of these. And a '72 pickup might as well have been a truck from the 30s*!* In terms of ride comfort and handling pickups (and cars in general) made in the last 25 years are several orders of magnitude more sophisticated…
the old Jeep Comanche pickup was unibody, and the new Ford Transit chassis-cab and cutaway vans are also.
Seconding the remarks about heavier pickups - my F350 can take a significant load that would require a massive unibody to handle adequately. The frame on that sucker is impressive.
Furthermore most larger ‘work’ trucks prefer to have the cab only option so that aftermarket specialty beds or cargo compartments can be used instead of the standard bed.
I imagine on smaller trucks a unibody might be an option.
Unibody pickups would probably be fine for the suburban cowboy sofa & mulch haulers. But I sincerely doubt they would hold up to the towing, hauling, and plowing that some people actually use them for.
For the record, I’m one of those suburban pickup owners who only rarely pushes the limits of the vehicle, but when I do pick up (heh) a yard of stone dust, or use 4wd low to pull something, both of which I do now and again, I am glad there’s a proper frame to underpin the effort.
I have owned a Ridgeline for a couple years now. The bed and rear bumper are no higher than any other 4 wheel drive pickup. It’s about 2 inches lower than my FIL’s 2 wheel drive F-250. The 5 foot bed and rather lame carrying capacity means I can’t carry much of a load. But I love the under bed storage and the 2 way tailgate. I also challenged an off road course a few months ago. Many jacked up 4 wheel drive rigs had some issues while plying the course. Myself and 2 other guys in Ridgelines had no problems completing the course. We all locked in the VTR-4 system, dropped the tranny into low and just had to avoid the real deep stuff. I did it with all season Michelin radials, no off road tires for me.
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Seconding the remarks about heavier pickups - my F350 can take a significant load that would require a massive unibody to handle adequately. The frame on that sucker is impressive.
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I’m trying to visualize how bent up a unibody pickup might get if you tried to tow a 10,000 pound travel trailer with a weight distributing hitch. If it’s balanced right, there’s about 1,000 pounds being borne by the truck at a 2x2" hitch receiver point of contact, and the WD hitch will distribute that weight through the truck as 250 pounds per wheel.
Many pick-ups are still used as trucks.
The small mountain county government I work for has at least a dozen pickups. Each one is fitted with a plow, and an number of them have lifts on the back. They use the plows for the county government parking lots.
I work for the county, but I drive a desk. My personal truck for home use has a plow on the front and a 10,000lb winch on the back.
If there is a uni-body out there that can take that kind of abuse, I have yet to hear about it.
The thing to consider about unibody is that’s it’s unibody, i.e., the entire body structure participates in the rigidity and strength of the vehicle. With a body on frame, the frame is doing all of the work, because the body is just payload and is quite literally just along for the ride. Trailer weight, winch wait, plow resistance, etc., are all borne by a super rigid, super strong network of high strength steels GMAW’d together, and directly connected to the drivetrain.
Yeah, I’m a suburban pickup owner too, and while I usually don’t do squat as far as taxing things are concerned, about 12 years ago I actually had the guys at Home Depot load a pallet of paving stones into the bed of the Ford Ranger that I had at the time. I thought that the suspension or engine would be the issue; not at all- they just chugged along merrily, while braking was the real issue- it was a lot harder to brake than I’d expected.
I’m not so sure how a unibody truck of similar size would have handled an entire pallet of paving stones…
That would seem to suggest that you could build a unibody pickup that weighed much less than any body-on-frame truck because it’s not hauling around as much dead weight (the bodyshell).
You and I are apparently dealing with different kinds of pallet loads here. A paverstone at Home Depot weighs 3.4 pounds. A pallet usually is 144 items, so you’re talking about 489 pounds in your Ranger.
My Ridgeline has had 1/2 pallet of retaining wall blocks from Home Depot in the bed, each block weighed 21.2 pounds which means I was at 1,512 pounds, just for the bricks. Of course, payload would include myself as well, so I was about 212 pounds over the max payload in the owners manual, but I knew it was less than two miles to my house, and I could go 35 mph the whole way without impeding traffic.
My suspension squatted rather dramatically, but never bottomed out. The unibody itself had no problems with the load. Suspension was for sure the weak point compared to the unibody.
On subsequent trips, I only took a 1/4 pallet at a time, just to not strain the suspension so much.
I have also towed a 4500# sailboat with the Ridgeline, and no issues.
It’s really a great vehicle.
How about “pickups” based on fwd cars…what the Aussies call Utes?
VW Caddy
http://www.avtosklad.bg/img/cars/1335946794xx_vw_caddy_i_82_92_l.jpg
Plymouth Turismo Scamp
I left out the Chevy ElCamino and Ford Ranchero because they are body-on-frame vehicles.
Don’t forget the Dodge Rampage, their version of the VW pickup.
That’s not entirely true.
The pickup bed was supported by a subframe, which was unitized to the cab frame. but the bed was removable. It wasn’t like the Ridgeline.
Utes are not necessarily or even generally based on front-wheel-drive cars. The Holden Ute is based on the Monaro, which in turn is based on the VT, all of which are rear-drive (though derived from the front-wheel-drive Vauxhall/Opel Omega).
The odd thing is that while Utes are unibody cars, they come with live axle rear suspensions and you can get them with cutaway chassis cabs which would sort of make them body on frame behind the B-pillar.
http://www.ford.com.au/commercial/falcon-ute/models/xr6-cab-chassis
The FIAT Ducato/Ram Promaster is also a sort of hybrid.
The cab is a unibody construction but integrates the drivetrain and it has a Macpherson strut front suspension that puts the load on the unibody, but there is also a ladder frame throughout. I’m curious about what the advantages of such a setup would be, from anyone more knowledgable on this stuff.
The question is not whether a pickup could be built unibody and still retain the useful characteristics of a truck, the question is where the limits are. Hauling even 2000lbs in the bed is just scratching the surface, and is limited more by suspension and brakes. It’s things like plowing, stump pulling, and towing really heavy loads that will stress a unibody.
As I said upthread, a vehicle like the Ridgeline (which does, I believe, have a subframe grafted on, though I am open to being corrected on that) will do the work the average homeowner will call for. But given how badly plows beat the crap out of BOF trucks, I can’t imagine a unibody holding up to it. The max towing capacity of a Chevy 1500 is 12,000 lbs. A Ridgeline caps out at 5,000. If it were just a matter of increasing the bakes and adding more transmission cooling, I am sure they would offer a towing package that allowed for more than 5,000 lbs.