Posted 2005-06-08 4:58 AM (#722) Subject: Truck frame question for Mr.Truck
Posts: 634
Location: Tipton, IN
First, I will gladly read all your posts, but I'm looking for the consumate professional opinion of Mr.T on this. Here goes. I am a died in the wool Ford guy and I believe they have the heaviest(robust) frame of the big3. So what are the actual box/rail dimensions and wall thickness of the 3 respectivly?
Posted 2005-06-08 7:49 AM (#723 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 1563
Location: North Carolina
Efaubert .. Unless you want a mobile balloon anchor, the heaviest frame isn't important. frame stiffness, vibration damping, torsional strength, end to end bending, etc is what effects the handling and load carrying abilities of a truck. The design of the metal shapes and their connections is what gives the frame strength without excess weight.
Posted 2005-06-08 7:59 AM (#725 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 727
Location: sc
Originally written by hosspuller on 2005-06-08 8:49 AM
Efaubert .. Unless you want a mobile balloon anchor, the heaviest frame isn't important. frame stiffness, vibration damping, torsional strength, end to end bending, etc is what effects the handling and load carrying abilities of a truck. The design of the metal shapes and their connections is what gives the frame strength without excess weight.
true, if it is the heaviest id like to know why? lower grade material? makeing up for some other short coming?
Posted 2005-06-08 8:02 AM (#726 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 634
Location: Tipton, IN
They all have short comings. Even my beloved Fords' I am sure. But from the structural standpoint, which is the strongest overall is what I am wondering. If it's GMC/Chevy, so be it, it still won't alter my opinion of what I want. I just want an informed opinion as to which manufacturer has the BEST frame.
Posted 2005-06-08 11:28 AM (#728 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 1563
Location: North Carolina
Originally written by efaubert1 on 2005-06-08 8:56 PM
Ok, lets talk semantics, and we'll change my word from heaviest to robust. That work?
The original post asked for rail thickness and box dimensions comparisons, I don't think it's semantics. But sure... it's your posting. I'd like to know too.
Posted 2005-06-08 1:03 PM (#729 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 634
Location: Tipton, IN
Chadsalt, no I'm not trolling. I don't like newer Chevys, but have owned a great number of 1979 and older ones I loved. I got a bad taste for Dodge in 1982, when I bought a 1981 with a straight 6 that blew up with less than 40K miles on it.
Hosspuller, the frame with the thickest wall section may not be the strongest or the heaviest depending upon the configuration. What spurred me to ask is the stupid commercial they have with Toby Keith for Ford where he walks in with a section of frame from all 3 brands. Just looking to find out how valid Fords claim is here.
Posted 2005-06-08 8:41 PM (#730 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 30
Location: Denver CO
Hi, the Ford Super Duty replacing the Heavy Duty 97 and older was 1/8 inch thicker, again thicker in 2005 Super Duty being boxed under the engine and more frame cross member gussets. Ford 2005 is saying it's 10-17% thicker than 2004. The F450/550 is a thicker frame than F250/350 by at least another 1/8 inch as it was in 99, the difference between the pickup frame and the cab and chassis frame. It's been a one piece cold rolled C-channel frame since the 99 model. I just looked threw all my Ford spec press releases and don’t see an exact frame thickness. I know I have it somewhere on disc, it will just take a while to find it.
Dodge starting in 2003 on 2500/3500 are a 4 piece boxed frame with hydro-formed bed uprights and some gussets. GM I can't remember the year, but on HD2500/3500 it's a three piece frame with engine section being hydro-formed, middle piece stamped C-channel and the last piece under the bed cold rolled C-channel. There is a tinsel strength rating on these frames and that I'd have to look up.
There are two main theories at work with frames. The old one used by Ford on Super Duties and semi trucks using the flexible C-channel frames that twist under load and drive train torque.
The newer direction for frames is the boxed and boxed hydro-formed. The new Ford F150 starting in 2004 has a totally boxed frame that is hydro-formed. The Nissan Titan has a boxed frame. All Dodge trucks have a boxed frame. Using a stiffer boxed frame allows engineers to dial in the suspension for an improved ride.
The verdict is still out whether boxed frames will handle the weight loads on heavy duty pickup trucks. Dodge is doing well so far with 3 years of boxed frames. C-channels are easier to mount bed ball hitches and air bags. But the aftermarket manufactures are adapting to the boxed frame.
Posted 2005-06-09 5:39 AM (#732 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 30
Location: Denver CO
It could happen, on the Dodge the end is open where the reciever hitch bolts in and there are holes on the side of all of box frames. Water would run out the holes in the bottom, mud might stay awhile. Frames are galvanized now and coated, they weren't in the seventies. Toyota has used boxed frames for decades as has most Japanese trucks. A chrome moly that wasn't a high grade metal. There is a lot of history in those Land Rovers after WWII with GM engines.
Posted 2005-06-10 10:34 AM (#733 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 2621
A fun question and given the ad that prompted it... well its just an ad and I think we ALL know that there is some parameter that a manufacturer's ad agency can pick on and proclaim "best in class". Where 'class' is undefined, but typically means only products that fall short of this one on this parameter. Ad_geneering - Bleah
There is a lot more to (good) design than material thickness, cross section, stiffness, how formed {"hydro" (-: } etc.
For pulling horse trailers I think a much more interesting parameter and one that we CAN get from spec sheets is Payload. This is a reflection of how strong the bed/chassis is and how much load carrying capacity the truck has.
This is also the param that folk are bumping up against time and again in this forum. We see the answer over and over "Sure that truck could PULL it, but that truck can't CARRY (20 or 25% of) it." (Paraphrased)
Posted 2005-06-10 12:17 PM (#734 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 30
Location: Denver CO
Along the same lines as marketing trucks, Truck manufactures decide what their GVWR, payload, GCWR etc. is. Oh sure they test things, measure things, and then decide what numbers they will stand by. Bottom line is what warranty liability do they want to pay out. Kind of like a drug company deciding how many lawsuits will be still profitable before they pull a drug. It's all about cash flow.
What concerned me is as trucks have become more competitive, each year in the race for more power and payload, some manufactures raise payload and tow capacity without doing anything to the truck physically. That didn't make since to me and shows who decides these towing/payload #'s that the insurance companies and law enforcement folk consider the final word.
I've been giving Ford a hard time for years because their payload and towing capacity was below Dodge and GM. Not that they couldn't tow/haul as much, but that's the numbers Ford chose to stand behind. Then in the 2005 Super Duty, they finally raised their payload/towing ratings above GM and Dodge, but not just numbers, I was happy to see the numbers were justified in real changes to the truck like thicker frame, more gussets, thicker wheels, larger brakes, thicker axle tubes, heavier front suspension etc. So my hats off to Ford raising their ratings and backing it up with a stronger truck.
Posted 2005-06-10 2:36 PM (#735 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 2621
I had thought (still do) that the manufacturers had to prove to DOT (NHTSA or some gummint body) that their vehicles were at least nominally safe at their rated capacities. I think there is some proof required that they can join traffic on freeway ramps by being able to accelerate adequately, brake to a safe stop from highway speeds, take some test curve at given speed, all at rated load. At least I thought I had read about this once upon a whenever...
I guess I believe that if Ford has upped their numbers recently it is because they have beefed things up and are now ABLE to show higher ratings to the authorities that require the proof. Whether marketing dept pull or engineering dept push has caused it - depends on the company, how it is run, who calls which shots, etc.
I think we're going to be seeing smaller lighter trucks in the market place REAL SOON NOW, suvs too (-:
Posted 2005-06-10 3:28 PM (#736 - in reply to #722) Subject: RE: Truck frame question for Mr.Truck
Posts: 30
Location: Denver CO
They definitely go threw tests and guidelines. But the actually payload and towing numbers come from the truck manufacture not the EPA as in gas mileage. They get tested by the insurance institute for crash ratings. But the government does not come up with tow ratings. The GVWR for a truck is from truck classifications, class 3, 4, 5 etc. That's what I'm saying. These tow ratings are taken as the gospel but are a combination of warranty liability, marketing and specs.